JP2010266347A - Geological structure survey system and method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a geological structure original position survey system for integrating and analyzing measured data obtained from each sub-system. <P>SOLUTION: This geological structure original position survey system 1 is constituted of an S-wave structure survey sub-system 100, a core sampling sub-system 200, a JFT measuring sub-system 300, a hole bottom shear strength measuring sub-system 400, a hole inside horizontal loading test sub-system 500, a bore hole television sub-system 600, and a multi-element data integration sub-system 700. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a survey system and method for a geological structure, and more specifically, exploration / investigation / analysis / confirmation of a support base for installing important facilities such as main structures and a geological structure above and below the support base. The present invention relates to a system and method.

  Prior arts and their problems will be described below. When the existing safety review guidelines are applied to or applied mutatis mutandis to the main structure, various exploration, numerous borings (for example, group boring characterized by precise vertical boring), indoor analysis tests, and surveys Expensive horizontal shaft inspection to confirm the result in-situ (if mismatched surface / crack is detected, it is usually forced to extend in the horizontal direction, and the sketch wall is sharpened) and the horizontal shaft in-situ location Implementation of tests, etc. or application thereof is required (hereinafter referred to as horizontal shaft survey).

  Investigations by horizontal shafts or the like in the safety examination guidelines described above tend to be applied mutatis mutandis to various important facilities regardless of the degree of environmental impact that is assumed to originate from the facilities.

  The cause of the request for such an excessive exploration, boring survey, and horizontal shaft in-situ test is that the existing exploration lacks accuracy, mobility and economy, even if the depth is about 100 m from the surface layer, and the conventional type The boring survey is limited to survey information in a point distribution (for example, even when performing group row boring or oblique boring, not as a system but as a single oblique line in stereoscopic view). For this reason, it is difficult for conventional survey methods to detect sharply-sloped slip surfaces, fracture zones, and misaligned surfaces that are difficult to estimate from the ground surface, and fault outcrop information in conventional lineament surveys cannot be obtained. However, it was only a qualitative description, and as for the confirmation method for depths of several tens of meters below the ground, there was no way to confirm whether or not there were underlying faults and slip surfaces.

  In particular, in conventional boring, all-core sampling is said to be easy to cause loss of core fines and loosening of the core based on the water pressure of the drilling water, and the core quality is such as gravel, crushed part, sandy part, clay, It was not able to withstand the determination of geological structure and slip surface, etc. for complex strata containing any of mudstone etc. (In the conventional technology, the core collection rate of 100% means that fine particles, that is, the matrix is washed away. Even if it was allowed). In particular, for gouges that are deeper than a few tens of meters deep and have a low degree of consolidation (a clay layer with a low degree of consolidation including crushed debris), the investigation techniques for collecting high-quality cores were completely ineffective.

  In addition, the planned construction site was selected based on the geological structure information (data quality, creation of database, error theory related to “fluctuation”, and various uncertainties were included because comprehensive analysis was not performed). In order to confirm the in-situ position, we have carried out lithological sketches and in-situ in-situ shear tests, etc. in the side pit survey, which was a heavy burden in terms of cost and time. In some cases, sketches were required for tracking and polishing of the pit walls.

  In addition, the estimation of underground faults and slip surfaces from the surface has been conducted by topographic and outcrop surveys by reconnaissance (limited to estimation from those exposed on the surface), and lineament surveys by decoding aerial photographs. However, in order to confirm the underlying faults, slip planes, and inconsistent planes, it is necessary to rely on group row boring or side tunnel sketches, and support bases for existing important facilities. It was difficult to grasp the strata directly under the surface (because the survey below the horizontal shaft survey level was not possible) without damaging the support base. It was also difficult to change the depth of the support plate slightly deeply and flexibly at the planned construction site of important facilities (in the conventional idea, the horizontal pit was extended in the horizontal direction and the wall was polished and sketched. ).

  Hereinafter, each conventional exploration / core collection method and horizontal shaft mechanics test method will be illustrated and described. PS logging, which is one of the conventional exploration techniques, has the advantage of large reach depth and distance, but uses refracted waves, so it does not directly grasp the S wave structure, and the groundwater level There are problems with the resolution due to various interference elements such as the use of gunpowder as a transmission source.

  The reflection method exploration, which is another conventional exploration technique, can expedite the S wave structure from the surface layer to several hundred meters, but near the surface, depending on the wavelength of the elastic wave, the permeability to the ground It is difficult to display the geological structure with high accuracy and three-dimensionality due to the precise survey line due to the high cost of implementation and the difficulty of the resolution rapidly decreasing, the resolution being limited, etc. It was virtually impossible to ask for sex (change of survey line depending on the situation).

  The microtremor array exploration method, which is still another conventional exploration technique, arranges multiple Rayleigh waves propagating in the ground out of vibrations caused by coastal waves etc. (usually tens to hundreds of arrays). This is a method for estimating the S-wave structure of the target formation by measuring with a detector and analyzing the phase velocity reflecting the ground characteristics, and has the advantage of high mobility. However, although it is suitable for measurement analysis at a depth of -50m to -1000m from the ground surface due to the characteristics of surface waves, it takes time to analyze a large amount of data in multipoint / complex geological formations. Signals near the ground surface are extremely weak and have low resolution, which makes measurement and analysis difficult in shallow formations.

  The surface wave exploration method using an artificial transmission source, which is still another conventional exploration technique, is limited in the energy of the transmission source (using a shading) and the capability of the receiver (generally 4. From 5 Hz), the measurable depth has been shallower than 20 m from the ground surface. There is a method of using a shaker as a method to compensate for the energy shortage, but there is a disadvantage that it cannot be used on complicated terrain such as undulations and marshes.

  All-core sampling using normal water, which is one of the conventional geological survey techniques, is a method that is expected to provide geological information in the depth direction and obtain a borehole with the core. If it sees, it has only brought information as a point. Furthermore, in the case of silt layers, mudstones and fracture zones with low consolidation, or peat layers and sandy mudstone layers with low consolidation, sandwiching boulders and sand, pores based on the water pressure and volume to eliminate slime. As a result, the matrix is washed away, resulting in turbulence, and obtaining cores and boreholes that are sufficient for making accurate judgments that cannot be interpreted in various tests such as geological structure estimation and geochemistry / hydraulics. I could n’t.

  As another conventional geological survey technique, there is an all-core sampling method that uses mud for ordinary boring to adjust the specific gravity of drilling water and protect the hole wall. In a peat layer or sandy mudstone layer with a low degree of consolidation, such as a crush zone or breccia / sand, even if it is slightly improved compared to freshwater digging, As a result, turbulence occurred due to the loss of fine particles, and it was impossible to obtain a high-quality core and high-quality boring hole sufficient to make an accurate judgment without interpretation in the geological structure estimation. The use of muddy water is disliked as a construction method that causes fatal disturbance such as clogging and sorption, especially in various tests such as geochemistry and hydraulics. Furthermore, the information obtained by this survey method remains as point information when viewed in plan, as in the case of the fresh water digging boring method.

  As one of the prior arts, there is a so-called horizontal shaft survey method to confirm the geological structure directly above the support base of the main building. In this survey method, in order to confirm the location of the main structure, a preliminary survey combining conventional exploration and conventional boring is conducted, and then a vertical shaft for access is provided. In the two horizontal shafts crossed around the center, the presence of ground instability elements is confirmed by sketches in the horizontal shaft, etc. of the geological structure, especially faults, slip surfaces, and inconsistent surfaces that are difficult to detect from the surface layer. Conduct such surveys. Next, in order to confirm the laboratory test results of the rock collected by conventional boring at the current position, a rock shear test or the like is carried out in a horizontal shaft that requires a great deal of cost.

  The shortcoming of this survey method is that the geological structure of GL-100m from the surface layer has uncertainty in the conventional exploration method (for example, even the reflection method that is considered to be relatively accurate, In the selection of the center of the horizontal shaft survey that requires enormous costs, the normal boring method used in combination is generally difficult to collect high-quality cores, because the resolution is limited and expensive and therefore lacks mobility. Uncertainty (incidentity) is unavoidable, and for precise mine wall sketches, it is necessary not only to clean the hole walls but also to polish them. When finding a buried fault or inconsistent surface, it was necessary to extend the horizontal shaft and continue the survey.

  In short, there are uncertainties in the accuracy of the conventional conventional exploration method due to the accuracy of the conventional exploration method and the core sampling by boring, the laboratory analysis test, and the horizontal pit survey. In low-consolidated mudstone, siltstone, and fractured zone including sand, gravel, and fractured rock, the reliability of the lithology is low and the vertical excavation is information as a point and the oblique excavation is information as a dotted line In order to avoid damage to the main structure installation base, the cross-sectional survey to confirm the geological and lithological information at the in-situ location is limited to the confirmation by the sketch directly above the base, and the depth below Not only is it ineffective at detecting matching surfaces and slip surfaces and their three-dimensional display, but there is no place to contribute to the analysis method for the flow direction and flow velocity of a specific stratum of interest. It was.

  Therefore, laboratory test results, drilling data, geological structure information, ground strength information, weathered zone information, information on slip surface / misalignment surface / fracture zone, hydraulic / hydrological data, etc. can be retrieved on the map at any time. As a database, it was not possible to comprehensively display them in a three-dimensional display or cross-section using the inverse analysis method.

  In addition, as a conventional technique, there is a method of detecting and confirming underlying faults, slip planes, and inconsistencies from the ground surface using borehole excavation. The construction of a horizontal shaft or a large-diameter vertical shaft was required, and a large-scale construction lacking mobility in terms of cost and time was required. In addition, there are A-type and B-type in-hole loading test devices as conventional in-situ testing devices for obtaining the deformation coefficient, yield pressure, and ultimate pressure number of the ground rock by pressurizing the hole wall in the borehole. The A-type in-hole loading test device is a test machine with a uniform distribution load method, and the measuring tube is composed of a measurement tube made of rubber tube in one chamber. In addition to controlling the pressure, a pressure gauge and a stand pipe for measuring the displacement are provided. The B-type in-hole loading test device is called the uniform load system, and the measuring tube is composed of three chambers: a rubber tube measuring main cell and upper and lower guard cells. The pressure control uses a pressure reducing control valve. The pressure difference is kept constant by an automatic control valve, and is a testing machine having a pressure gauge, a stand pipe for measuring displacement, and the like. In the A-type in-hole loading test device and the B-type in-hole loading test device, high pressure gas or a pump is used to supply pressure through a connecting pipe for pressure loading. At the same time, even in the connecting pipe, there is a need for a small expansion amount with respect to pressurization because of fear of pressure loss. The length of the measuring tube should be long enough to allow the cylindrical pressure field to be considered as two-dimensional. It is required to be at least six times the diameter, and there are restrictions on the calibration time, number of times, loading pressure, etc. Sufficient follow-up and measurement could not be expected for a slip surface with a low degree of binding. In addition to this, there is a C-type in-hole loading test device, which has a structure in which a part of the circumference of the measurement tube is a loading plate, and the measurement of the hole wall displacement is added together with a pressure control pump and a pressure gauge. Although it is a device that measures based on the amount of oil discharged from the pressure jack, it tends to be difficult to recover the device because it is caught on the hole wall, and its use tends to be avoided.

  As a conventional borehole test, after a vane blade is pushed into the soil against a viscous soil with a depth of reach of several tens of meters and soft rock with a low degree of consolidation (especially ground with a zero N value) Although there is a vane shear test that measures shearing force by rotating, it was not applicable from clay to hard rock.

  There is also a ring shear tester. It is a device (non-core measurement) that measures the rotation angle and the stress generated on the ground by attaching a cone with a metal blade to the contact surface radially to the tip of the rod and crimping it to the hole bottom with water pressure. The application depth is limited to several tens of meters due to the problem of measurement error due to the twisting of the rod between the ground and the bottom of the hole. It has been impossible to measure and use the same excavator from cohesive soil to hard rock. There is a rotary sounding device that measures the uniaxial compressive strength by rotating while pushing using a dedicated boring machine using a drag bit or two-cone bit, but only uniaxial compressive strength measurement is out of the question. This device has a very limited reaction force to push the bit, and the maximum application depth is about several tens of meters. There is also a shear test method that uses a large leading bore hole. Once the drilling is stopped and the drilling is continued further using a bit with a small outer diameter with respect to the bottom of the leading borehole, a reamer that opens the tip is applied to the borehole of the small bore to make a donut shape (A cavity with the same radius as the leading hole is formed on the lower side). A method for performing a rock shear test by opening a jig attached to the tip of a rod under a donut-shaped disk and pulling it out has been proposed. This method seems to be able to perform direct rock shear tests, but the smoothness of the bottom of the leading hole (generally, non-core drilling does not bite the bit and the accuracy is not accurate) and the center position of the small outer diameter drilling hole There are many problems to be solved, such as the accuracy of metal, the accuracy of donut-shaped disks by reamer excavation, the contact accuracy of the jig and the positional accuracy of the ground / rock in the shear test, and cost / time / accuracy, potential cracks or The possibility of the presence of a sandwich with a low degree of consolidation is not so easy. Furthermore, it is necessary to consider the relaxation of stress during the preparation time for which such accuracy is required, and the spread of the hole wall sketch cannot be expected. As another shear test method, a large-diameter vertical hole is constructed, and a hollow cylindrical rock mass (taken ring-shaped rock mass with the same shape as the specimen for indoor cylindrical shear test of soil) is self-supported and twisted. There is a method of performing a shear test. This method also has problems such as rock mass preparation accuracy and stress relaxation before the start of measurement, which is no longer a big difference from the block shear test by horizontal shaft construction, and the side wall borehole sketch to be performed together I cannot expect data with such a spread.

  An object of the geological structure survey system and method of the present invention is to solve the problems of the conventional methods by each subsystem. A further object of the geological structure survey system and method of the present invention is to integrate and analyze measurement data obtained from each subsystem.

  In order to solve the above-mentioned problems, the first invention is a geological structure investigation system, which uses a wave structure exploration subsystem for exploring a geological structure by measuring Rayleigh waves and reflected waves, and suspended bubble water. The core collection subsystem that drills the borehole and collects the borehole and collects the core, and the JFT measurement subsystem that measures the water quality and hydrology of the geology by performing a spring pressure test (JFT) using a water-impervious multipacker And a bottom shear strength measurement subsystem for measuring the strength of the geology by performing bottom shear at the bottom of the borehole washed with the suspended bubble water, and a horizontal inside hole for performing a horizontal loading test within the borehole. A multi-dimensional analysis of geology using a loading test subsystem, an in-hole imaging subsystem that images the borehole, and multi-element data obtained from each subsystem. And containing data integration subsystem, a geological survey system constituted.

  According to a second aspect of the present invention, in the geological structure survey system, the S-wave structure exploration subsystem includes a plurality of arranged at each vertex of a grid set on the ground surface in order to measure the Rayleigh wave and the reflected wave. A geological survey system with an array. A third invention is the geological structure survey system, wherein the array is composed of a plurality of receivers arranged at predetermined intervals. A fourth aspect of the present invention is the geological structure survey system, wherein the core sampling subsystem includes a vertical moat and / or a diagonal core sampling device.

  According to a fifth aspect of the present invention, in the geological structure survey system, the multistage packer of the JFT measurement subsystem includes an upper multistage packer disposed above the measurement site and a lower multistage packer disposed below the measurement site. This is a geological structure survey system. The sixth invention is the geological structure survey system, wherein the upper multi-stage packer and the lower multi-stage packer are a plurality of packers.

  The seventh invention is the geological structure survey system, wherein the hole bottom shear strength measurement subsystem has a conical crown that leads the excavation and secures a shear surface, and holds the core during excavation while rotating the core. It is a geological structure investigation system provided with a core lifter for ensuring that the core is lifted by shearing the core from the bottom of the hole.

  In an eighth aspect of the geological structure survey system, the horizontal loading test sub-system in the borehole includes a plurality of cells that measure pressure due to pressure feeding in the borehole and a change in the borehole wall due to the contacted cell. It is a geological structure survey system that measures a borehole wall pressure and displacement in a multi-dimensional manner by providing a plurality of displacement meters to be measured. According to a ninth aspect of the present invention, in the geological structure survey system, the plurality of cells of the in-hole horizontal loading test subsystem each include a deformation follower for causing the plurality of cells to follow deformation of the hole wall. It is a structural survey system. A tenth aspect of the present invention is the geological structure survey system, wherein the cells have elasticity and pressure is transmitted to each other.

  In an eleventh aspect of the present invention, in the geological structure survey system, the multi-element data integration subsystem records the multi-element data obtained by the subsystems and uses the multi-element data as a three-dimensional image. It is a geological structure survey system that analyzes and displays.

  The twelfth invention is a geological structure investigation method, which measures a Rayleigh wave and a reflected wave, explores a geological structure, and drills a borehole using suspended bubble water, A core collection process for collecting the core, a JFT measurement process for measuring water quality and hydrology by performing a spring pressure test (JFT) with multiple packers, and a bottom shear at the bottom of the borehole washed with the suspended bubble water Hole bottom shear strength measuring step for measuring the strength of the geology, in-hole horizontal loading test step for performing a horizontal loading test in the boring hole, in-hole photographing step for photographing the inside of the boring hole, and each of the above steps This is a geological structure survey method comprising a multi-element data integration step for performing a three-dimensional analysis of the formation using the multi-element data obtained in (1).

  According to a thirteenth aspect of the present invention, in the geological structure investigation method, the S wave structure exploration step includes a plurality of arrays arranged at each vertex of a grid set on the ground surface in order to measure the Rayleigh wave and the reflected wave. This is a geological structure survey method. A fourteenth aspect of the present invention is the geological structure survey method, wherein the array is composed of a plurality of receivers arranged at predetermined intervals. A fifteenth aspect of the present invention is the geological structure survey method according to the geological structure survey method, wherein the core collecting step includes a vertical moat and / or inclined core collecting device.

  According to a sixteenth aspect of the present invention, in the geological structure survey method, the multi-stage packer of the JFT measurement step includes an upper multi-stage packer disposed above the measurement site, and a lower multi-stage packer disposed below the measurement site. This is a geological survey method. A seventeenth aspect of the invention is the geological structure investigation method, wherein the upper multistage packer and the lower multistage packer are a plurality of packers.

  According to an eighteenth aspect of the present invention, in the geological structure survey method, the hole bottom shear strength measuring step includes a core catcher that shears the core from the hole bottom by rotating and loading while holding the core during non-digging. This is a geological survey method that measures the tensile strength.

  According to a nineteenth aspect of the present invention, in the geological structure survey method, the in-hole horizontal loading test step includes a plurality of cells for measuring pressures in the borehole and the measurement cell, and a plurality of for measuring displacement of the borehole wall. It is the geological structure investigation method which measures the pressure and displacement of a boring hole wall multi-dimensionally by providing a displacement gauge. According to a twentieth aspect of the present invention, in the geological structure investigation method, the plurality of cells in the in-hole horizontal loading test step each include a deformation follower for causing the plurality of cells to follow deformation of the hole wall. It is a structure investigation method. A twenty-first aspect of the present invention is the geological structure survey method according to the geological structure survey method, wherein the position holding tool is bowl-shaped and elastic and is attached around the cell.

  According to a twenty-second aspect of the present invention, in the geological structure survey method, the multi-element data integration step records the multi-element data obtained in each of the steps and displays the multi-element data as a three-dimensional image. This is a geological survey method.

  The geological structure survey system according to the present invention includes three-dimensional estimated values of buried faults, inconsistent surfaces, and slip surfaces estimated from the S-wave structure by the S-wave structure exploration subsystem, high-quality borehole formation, and high-quality core. Geological and structural data obtained from core data collected using the sampling subsystem, confirmation of geology and structure obtained by the borehole observation subsystem, horizontal loading test subsystem in the borehole, and bottom shear test and tensile strength Obtain the flow velocity (or velocity line) distribution in the ground rock from the in-situ test by the test and the hydraulic and hydrological information from the in-situ permeability test by the JFT measurement subsystem and the pore water pressure test. In addition, using these multi-element data, the multi-element data integration subsystem enables a three-dimensional three-dimensional or planar display of geological structures (further, Surface display) become possible.

It is a block diagram which shows the geological structure in-situ survey system of this invention. It is a figure which shows the principle of the S-wave structure search subsystem 100 of FIG. It is a block diagram which shows the core collection subsystem of FIG. It is a perspective view which shows arrangement | positioning of the S wave structure search subsystem of FIG. 1, and a core extraction subsystem. It is a principle figure which shows the effect of the geological structure confirmation by the core extraction subsystem of FIG. It is sectional drawing which shows the JFT measurement subsystem of FIG. It is sectional drawing which shows the hole bottom shear strength measurement subsystem of FIG. It is sectional drawing which shows the horizontal loading test subsystem in a hole of FIG.

The geological structure in-situ survey system (geological structure survey system) and its method according to the present invention are simply implemented in the borehole (or hole bottom, core, etc.) regarding the stratum and in-situ characteristics of the support base where the important structure is installed. To do. Hereinafter, an embodiment according to a geological structure in-situ survey system and method of the present invention will be described with reference to FIGS.
[System overall configuration]
The overall structure of the geological structure in-situ survey system 1 of the present invention will be described with reference to the block diagram of FIG. In FIG. 1, a geological structure in-situ survey system 1 includes an S wave structure exploration subsystem (wave structure exploration subsystem) 100, a core sampling subsystem 200, a JFT measurement subsystem 300, and a hole bottom shear strength measurement subsystem. 400, an in-hole horizontal loading test subsystem 500, a borehole television subsystem (in-hole imaging subsystem) 600, and a multi-element data integration subsystem 700.

  The S-wave structure exploration subsystem 100 measures an Rayleigh wave and a reflected wave by arranging an array, which will be described later, at the top of the grid. The core collection subsystem 200 collects the core by forming a hole wall using suspended bubble water and using vertical and oblique drilling at the top of the grid. The JFT measurement subsystem 300 performs a multipacker spring pressure test (JFT) to measure the hydrological situation. The hole bottom shear strength measurement subsystem 400 forms a borehole in accordance with fresh water digging by using suspended bubble water by a drilling device included in the core collection subsystem 200, and creates a fresh hole bottom formed at an arbitrary depth. A hole bottom shear test is performed immediately after washing with suspended water.

  The in-hole horizontal loading test subsystem 500 performs a horizontal loading test in a boring hole in a multiple manner. The borehole television subsystem 600 automatically observes the inside of the hole by the borehole television inserted in the borehole, analyzes it with a predetermined algorithm, and records the observation and analysis results. The multi-element data integration subsystem 700 collects and stores data obtained by each subsystem, thereby constructing a database that integrates multi-element data, performs a three-dimensional analysis of the formation, and displays an analysis result as an image. . As a result, the multi-element data integration subsystem 700 enables confirmation of underlying faults, slip planes, inconsistent planes, and strike direction confirmation.

  In the geological structure in-situ survey system 1, it is possible to detect and confirm acute angles or upright underground faults, slip planes and inconsistencies above and below the support base of important structures that were difficult to detect from the ground surface. In addition to eliminating the need for a horizontal borehole survey (or active fault excavation survey), the borehole shear strength measurement subsystem 400 and the horizontal borehole loading subsystem 500 using the boring method can eliminate the need for a conventional horizontal borehole survey. Can do.

  In the prior art, it was not possible to detect the hidden faults, slip planes, and inconsistencies from the ground surface, and it was impossible to efficiently and efficiently confirm the faults. Subsystems 100-300 made this possible. However, as an in-situ test, a large-scale shear test or horizontal loading test was inevitably performed on a conventional horizontal shaft or vertical shaft.

  On the other hand, in the present invention, the in-situ rock test in the horizontal or vertical shaft is performed by the bottom shear test by the bottom shear strength measurement subsystem 400 and the horizontal load test by the in-hole horizontal load test subsystem 500. By implementing in a plurality of boreholes at any depth, in-situ rock properties can be obtained not only above and below the support base but also in the entire ground. That is, at the point of interest, measurement analysis of the deformation characteristics of the ground bedrock (c, φ value measurement analysis for sedimentary soil / soft rock) can be performed by the horizontal loading test in the hole. The horizontal loading test and the bottom shear test in these boreholes demonstrate their effects only by selecting the appropriate site characterized by the vertical and oblique excavation where the test position is selected flexibly.

  Furthermore, as shown in FIG. 4 to be described later, by combining control boring / fixed orientation boring with the geological structure in-situ survey system 1 of the present invention, it is possible to confirm whether there is a fault crush zone, slip surface, etc. In-situ rock strength tests can be performed with high accuracy, and high-precision geological / structural surveys and rock strength in-situ tests can be performed flexibly and economically without leaving many openings.

  The geological structure, stratigraphy, ground strength, hydraulic / hydrological information, flow direction / velocity / trajectory information, etc. obtained from each subsystem, and rock mass test results from the ground surface are integrated into the multi-element data integration subsystem. By 700, the data is displayed as data that can be displayed on the map at any time, and then each data is subjected to three-dimensional analysis by inverse analysis and displayed as a solid image or a cross section. Since the actual measurement data has “fluctuations” as a natural phenomenon, the data obtained from the present invention and the analysis results thereof can be recorded or displayed as errors.

As described above, in the present invention, the detection of geological structures such as buried faults, slip surfaces, inconsistent surfaces and the like by the S wave structure measurement analysis of the support base between the surface and the depth of about −100 m and the ground Rock strength can be obtained effectively. In addition, it is applicable to about GL-1500m.
[S-wave structure exploration subsystem]
The S-wave structure exploration subsystem 100 dynamically detects a geological structure by measuring and analyzing an S-wave structure that combines a Rayleigh wave and a reflected wave. Specifically, the S-wave structure exploration subsystem 100 systematically arranges the micro-vibration array at the center point of a grid (measurement point) set on the ground surface. A boring hole is formed at the center point of the grid, as will be described later, and a weight drop type oscillation source is used that causes an observation wave to be generated by dropping a weight into the boring hole.

  As shown in FIG. 2, the S-wave structure exploration subsystem 100 includes surface exploration provided with systematic arrangement of oscillation sources at grid intersections and a device such as a reception frequency of about 8 seconds, and a natural Rayleigh. A plurality of microtremor small arrays (using a concentric multiple receiving device group shown in FIG. 2A as a receiving unit) that form a unique array using a wave oscillation source are combined.

  FIG. 2A shows a superposition state of an arrangement example of the S-wave structure exploration subsystem focusing on the phase wave velocity in Rayleigh wave propagation (however, only one survey line), and FIG. An example of the array of the structure exploration subsystem 100 is shown. As shown in FIG. 2, the S-wave structure exploration subsystem 100 sets the surface wave exploration survey line of FIG. 4 on a grid assumed on the ground surface at a predetermined interval (for example, an interval of about 25 m).

  The S-wave structure exploration subsystem 100 synchronizes these by performing surface wave exploration at intervals of about 25 m and microtremor array exploration (see Fig. 2 (b) for receiver arrangement) on the same line. , And measured as S wave phase wave velocity modulated by formations of different depths.

  Note that the S-wave propagation velocity obtained by paying attention to the propagation velocity of the phase accompanying the Rayleigh wave generated along the coast of Honshu is uncertain (reflection) in GL-20m to -50m, which was caused by independent analysis in the past. According to the law, the signal was weak and the Rayleigh wave was blurred). However, in the S-wave structure exploration subsystem 100, the measurement points in both the Rayleigh wave and reflected wave exploration measurements are overlapped with each other in order to complement these data and to overcome the weak points in a planned manner. Place it systematically. Thus, the data obtained by both exploration methods (as a common S wave propagation velocity) is analyzed by the following analysis method.

  Since the propagation of the S wave velocity is affected by the underground geological structure, the S wave signal that reflects the influence of the same formation obtained by the measurement method is integrated (overlapped) to analyze the weakness of the conventional weak point. Three-dimensional analysis of the geological structure of the existing surface layer to GL-100m becomes possible. For example, in S-wave structural analysis, the data obtained by both Rayleigh wave and S-wave exploration methods can be used from the surface layer, which has been difficult to implement by the “combined simulation analysis method” that combines the inverse analysis method and the forward analysis method. GL-S wave structure up to about 100 m is obtained. This makes it possible to flexibly and economically compensate for the weak point of the S wave exploration between GL-20m and -50m, which was a conventional weak point, with the improved weight drop type oscillation source.

  Furthermore, the S-wave structure exploration subsystem 100 improves the shortage of artificial source energy against the “reach depth limit of the Rayleigh wave exploration method using an artificial earthquake, which is a conventional method (effective at shallower than GL-20 m)”. Measurement and analysis up to GL-100m is possible by increasing the weight of the mobile drop weight. In addition, the S-wave structure exploration subsystem 100 systematically arranges the transmission source and the receiver on the grid intersection, and arranges the receiver group having the characteristic period (8 seconds ± 2 seconds), so that the fault of the underground geological structure is obtained.・ Interpret slip surfaces and inconsistencies.

In addition, in this Rayleigh wave exploration method using an artificial oscillation source, even if a higher energy excitation device or vehicle is used instead of a falling cone type oscillation source, a combined analysis of Rayleigh waves is not possible. Not only can it do anything, it can increase the certainty of the data. In the concentric Rayleigh wave detection device (S-wave structure exploration subsystem 100) according to the present invention, it is possible to expand and multiplex more than 10 receivers or to use in combination with a single concentric Rayleigh wave detection device. The reach depth in grasping the properties is increased to about GL-about 3000 m. However, in terms of the nature of giving the average value of concentric phase velocity as a feature of Rayleigh wave analysis, the number is used in the present invention to “measure and combine analysis by matching the Rayleigh wave exploration method using an artificial oscillation source with a survey line”. This feature reduces the economic effect, but does not hinder the achievement of the object of the present invention.
[Core collection subsystem]
The core collection subsystem 200 forms a boring hole for vertical digging and oblique digging at the above-mentioned grid apex position, and digs up using an automatic slime function of suspended bubbling water for digging. This makes it possible to form a boring hole having a smooth boring hole wall and to collect the core in a substantial supernatant water moat. In addition, it performs boring by the automatic slime exclusion function of suspended bubble water, and it is a construction method that overcomes these disadvantages by taking advantage of fresh water digging and bubble boring.

  The core collection subsystem 200 is configured as shown in FIG. 3 and has an automatic slime removal function at the bottom of the hole by suspended bubble water. In the raw water tank 202 of FIG. 3, ground water or surface layer water is stored as raw water, and tap water is unavoidably stored, and the raw water tank 202 is also used as a groundwater settling basin. The raw water stored in the raw water tank 202 is continuously pumped by a water supply pump 204 through a water supply pipe to a liquid mixer 208 that generates bubble water suspended in a foaming gas. The foaming gas cylinder 210 and the gas-liquid mixer 208 are disposed outside, and the foaming gas cylinder 210 and the gas-liquid mixer 208 are connected by a gas supply pipe. The gas-liquid mixer 208 is supplied with foaming gas continuously from the foaming gas cylinder 210 through the gas supply pipe at the same time as the raw water is supplied. Therefore, in the gas-liquid mixer 208, the raw water and the inert gas are mixed and dispersed at a high speed to generate bubble water suspended in the foaming gas. In addition, valves 206 and 212 are arranged in the pipes before and after the liquid mixer 208. Suspended bubble water (fresh water) generated by the liquid mixer 208 is guided to the vertical excavation core collection device 220 and the inclined excavation core collection device 230 via a pipe. At the hole bottom of these core collection devices, the core 250 is excavated using suspended bubble water.

  In addition, as shown in FIG. 4 to be described later, the core collection subsystem 200 is intended to confirm the support base surface at the target survey position and the upper and lower geology / structure sandwiching this, and minimize damage to the support base surface. For this purpose, boring and all-core sampling, which is characterized by oblique excavation performed systematically (systematically, at predetermined intervals), is performed on the four sides of the target support base region.

  Note that when the reflection method and Rayleigh wave measurement points are arranged at the grid apex as in the S-wave structure exploration subsystem 100, if the ground bedrock with similar bulk density or the layer thickness is thin, the resolution is limited. Therefore, there is a limit that it is difficult to make accurate analysis and image expression precise and clear in different ground rock facies (for example, mismatch). As described in the section of the prior art, many vertical borings that form group rows are not suitable for detection of subsurface faults, slip planes, and inconsistencies that are close to the vertical, and damage to ground rock masses. In order to overcome this problem, the core collection subsystem 200 is devised by focusing on the fact that it is close to labor. This core collection subsystem 200 uses the “Shimizu Mine Core Collection Method” with “Automatic Slime Eliminating Function Using Suspended Bubble Water” instead of the conventional ordinary method (Shimizu Mine) boring. It is carried out in combination with a plurality of inclined borings and vertical borings.

  As for the arrangement of these vertical borings (see FIG. 4), a grid is formed at predetermined intervals so as to surround the center of the planned building site and this, and a vertical boring group arranged at the apex thereof is formed. An inclined boring group is formed so as to sandwich the vicinity of the arrangement. The geological structure survey boring system with oblique digging boring groups arranged in this way makes it difficult to confirm the presence / absence of underground faults, slip surfaces, and inconsistencies in outcrop and liniment surveys from the surface. It is possible not only to check the geology and structure with a wide structural extent, that is, depth and strike slope, but also to reduce the uncertainty related to the evaluation of the geological structure left in the complex surface wave exploration system, and to make numerical evaluation To.

  In the core collection subsystem 200, as an excavation method, application of “control boring using suspended bubble water”, application of “fixed orientation core collection using suspended bubble water”, and “depending on depth and rock type” “Replacement of crown, change from mud or surfactant to suspended bubble water”, “use of air pump and compressed air cylinder to generate suspended bubbles, nitrogen / argon as inert gas Changing the cylinders and their grades, using hydrogen-mixed inert gas cylinders, etc., are all right, and the same excavation system can be applied (use of suspended bubble water generation system and excavator). Not only does this impair the effect, but combining these elemental technologies as needed according to the hardness and softness of the ground rock increases the effect of the present invention.Further, as in the core collection subsystem 200, a method using nitrogen, high purity nitrogen, argon, hydrogen-filled argon, helium or the like instead of air may be used for the “fresh water core collection method”. In this case, not only crystalline rock but also mudstone with low consolidation, semi-consolidated mixed layer of debris like crush zone, mixed layer with low consolidation of gravel and clay, etc. smoothly In addition to being able to collect cores that are free of runoff and disturbance of core structure, microbiological tests, geochemical tests, environmental chemistry can be performed by changing the cores and groundwater according to the purpose of investigation. It becomes possible to correspond to a static test.

  In the core collection subsystem 200, a surfactant may be used for stabilizing the bubbles in the suspended bubble water, but even if a surfactant is not used, crystalline rock has a low degree of consolidation. Mudstone, semi-consolidated mixed layer containing debris such as shattered zone, mixed layer composed of gravel and clay, etc. with low degree of consolidation smoothly, without losing fine particles, and without disturbing the core structure Since it is possible to collect high-quality cores, it is advantageous to accelerate the process if there are no geochemical constraints.

  In the core collection subsystem 200, the same hole bottom shear test conical crown and excavation device are used in principle (the conical crown enables all core sampling (double core tube method), and the vertical excavation part and the hole bottom shear test). A hole bottom shear test weight crown composed of a diamond bit hill group arranged in a spiral shape to form a contact surface, and a device for measuring a rotation angle and a rotational stress are provided on the ground portion of the excavation rod.

Moreover, the excavation core collection device of the core collection subsystem 200 is arranged at each grid intersection (FIG. 4), and boring is performed by vertical moat or inclined excavation. Since the core collection subsystem 200 performs boring while cleaning the borehole with suspended bubble water, slipping due to adhesion / precipitation slime on the hole bottom / hole wall is eliminated, and a diamond bit is used. A smooth hole wall that is polished with diamond dust can be obtained. As described above, by using the core collection subsystem 200, it is possible to analyze the geological structure obtained by the S-wave structure exploration subsystem 100 with respect to the minerals and soil structure of the core sample, and to grasp the structural slip surface. It becomes possible.
[Arrangement of S-wave structure exploration subsystem and core collection subsystem]
FIG. 4 illustrates the interrelationship between the arrangement of the S-wave structure exploration subsystem 100 and the core collection subsystem 200. 4, a plurality of S wave structure exploration subsystems 100 are arranged on the ground surface 1000 at predetermined intervals as shown in FIG. 2, and a target construction surface 1100 is located in the ground below the ground surface 1000. The survey required depth plane 1200 is located at the survey required depth below the plane 1100. In FIG. 5, the conventional method boring 260 is performed up to the survey required depth plane 1200 at the outermost periphery with respect to the main structure position as the site survey. Further, as a support base survey, the vertical boring 270 of the core collection subsystem 200 is performed up to the survey required depth plane 1200 at the rectangular apex and the main building position of the outer peripheral position closer to the main building position than the position of the conventional method boring 260. . Further, the vertical boring 280 of the core collection subsystem 200 is performed at the midpoint of each side of the rectangular outer peripheral position as the outer periphery supplementary survey. In addition, as a tilt mismatch confirmation investigation, tilt boring 290 of the core collection subsystem 200 is performed up to the main structure ground contact surface 1100 within the outer peripheral position.

  In addition, the S-wave structure exploration subsystem 100 grasps data relating to different surfaces with different S-wave propagation speeds by exploring from the ground surface, and gives three-dimensional information on points and supporting base depths that are candidates for precise investigation. The core collection subsystem 200 is arranged at the grid intersection, and thereby it is possible to confirm a buried fault having a structural extension, a slip surface, inconsistency, and the like. By using the borehole TV subsystem 600 in the borehole, these data can also be measured for strike faults of underlying faults / misalignments / slip surfaces.

FIG. 5 is a principle diagram showing the effect of confirming the geological structure by the core collection subsystem 200 that performs vertical and oblique excavation by a systemized arrangement. Vertical excavation by conventional ordinary method
Although it was difficult to grasp the group fault boring and underground faults, inconsistencies, and slip planes from the ground surface (or by lineament survey), the core sampling subsystem 200 is an upright vertical fault / slip with a near vertical angle. Detection and confirmation of surface / misalignment is possible. Note that the S-wave structure exploration subsystem 100 and the core collection subsystem 200 can be implemented in parallel, and facilitate their flexible implementation by exchanging the obtained data (information) as needed. In addition, the data accuracy can be improved. Further, the geological survey by boring by the conventional method is performed so as to surround the high-quality vertical digging / inclined digging system of the present invention, or the geological survey using suspended bubble water itself is inferior in accuracy, but the present invention Improvement in accuracy is expected.
[JFT measurement subsystem]
The JFT measurement subsystem 300 is based on the measurement of recovery speed of the borehole water level in addition to the observation result of the borehole TV in a plurality of boreholes having high-quality hole walls obtained by suspended bubble water boring. Apply the spring pressure test (JFT) with multiple packers to the stratum, measure the hydraulic conductivity and spring pressure at multiple points, and measure the flow velocity of the groundwater in the specific strata To analyze.

  As shown in FIG. 6, the JFT measurement subsystem 300 includes a multistage packer JFT. This multistage packer JFT has an upper multistage packer 302 disposed above the target formation in the borehole 301 and a lower multistage packer 304 disposed below the measurement range which is the target formation. Each multistage packer is a double packer in FIG.

  Inside the borehole 301, a strainer (porous pipe) 318 equipped with a trip valve 314 is provided, and at the position where the target formation is sandwiched at a specific depth in the borehole 301, the pore water pressure of the target formation is first removed by removing the water in the hole. Form. Thereafter, pressurized water is fed to the multistage packers 302 and 304 through the pressure pipes 306 by the pressure regulator 308 so that the multistage packers 302 and 304 are brought into close contact with the hole wall. Sex is guaranteed. The strainer 318 has a large number of openings and is arranged on the tube wall of the measuring tube 317 located between the multistage packers 302 and 304. The spring water of the formation flows into the measuring tube 305 from the hole wall through the opening of the strainer 318. The trip valve 314 is disposed directly above the strainer 318 and below the upper multi-stage packer 302 and in the measurement tube 317, and closes or opens the measurement tube 305 above and below. After measuring the JFT internal pressure by the lower pressure sensor 312, the trip valve 314 is opened by the action of the falling cone 316, and the spring pressure and the hydraulic conductivity are measured by the upper and lower pressure sensors 310 and 312. The measured spring pressure and hydraulic conductivity are transmitted to the recording unit 322 via the communication cable 320 and stored.

As described above, this system enables the high-precision use of JFT in an arbitrary depth boring hole, which has been impossible in the past, because of the high-quality boring hole wall due to the use of suspended bubble water. The formation is fundamentally different from the conventional JFT, and the use of multiple packers enables highly accurate measurement of spring pressure and hydraulic conductivity. Moreover, the JFT measurement subsystem 300 can obtain the flow velocity of the groundwater in the specific formation from the measurement / analysis of the spring pressure and permeability measured in a plurality of boreholes without using a tracer or the like. The JFT measurement subsystem 300 can be applied up to about GL-1500 m. Furthermore, if the JFT measurement subsystem 300 is used, a water sampling apparatus equipped with a single pipe or a plurality of high vacuum pipes through one or a plurality of valves is used to collect the in-situ gas in the deep underground. Water does not impair the effectiveness of this subsystem.
[Hole bottom shear strength measurement subsystem]
The hole bottom shear strength measurement subsystem 400 collects all cores to any depth with a specially shaped bit in the hole bottom shear test, and once stopped, washed with suspended bubble water, and conducted a shear test on a fresh hole bottom. In the same excavation system, it is possible to repeatedly perform shear tests at arbitrary rock quality and arbitrary depth, and when recovering the core at the end of excavation, the tensile stress between the core catcher holding core installed in the inner tube and the rock mass Strength analysis is performed.

  As shown in FIG. 7, the hole bottom shear strength measurement subsystem 400 includes a specially shaped bit (cone crown) 402 at the tip of the outer tube 401. This bit 402 has a cone-shaped bit 402a in which a group of diamond hills arranged in a spiral shape is implanted in order to keep the contact with the bottom rock always fresh during the shear test, and a vertical leading excavation for collecting all cores at the tip thereof. And a tip bit 402b similar to the bit. In the bit (cone crown) 402, the tip bit 402b leads the excavation, and the cone-shaped bit 402a ensures a shear surface. The inner tube 404 also includes a core catcher (core lifter) 406 for securing the core 405 cut out by the bit 402 and a core sleeve 408. The core catcher (core lifter) 406 ensures the core lifting for shearing the core from the hole bottom by applying a rotational force while holding the core during excavation. In addition, when using suspended bubble water, cleaning in the hole is performed simultaneously with the excavation. Even if the vinyl sleeve 408 is used, the outer diameter of the bit 402 is slightly oversized with respect to the outer tube 401, and the outer diameter of the outer tube 401 and the diameter of the rod 410 are made to coincide with each other. Contact can be avoided. If further care is taken, it is conceivable to perform a new in-hole shear test in a hole having an appropriate clearance after inserting the casing, but for centering at the start of the bottom-shear test, Caution must be taken. Moreover, although the same excavation apparatus may be used to conduct a shear test on viscous soil, a metal crown may be used as the shear test weight crown.

  As shown in FIG. 7, above the outer tube 401, an in-hole rotation measurement unit 412 that measures and records the rotation angle and rotation stress (upper cone cone torque, digging pressure, and tensile stress) of the outer tube 401, and a suspension A water pressure measurement unit 414 that measures and records the water supply pressure from the bubble water supply unit 418 into the hole. Immediately before the hole bottom shear test, the excavation is stopped once and the tip of the bit (cone) 402 and the inside of the hole are cleaned using the automatic slime removal function of the suspended bubble water used for the excavation. Conduct a bottom shear test. This makes it possible to repeatedly carry out shear tests at an arbitrary depth on fresh soil and rock at the bottom of the borehole. Note that the rotation angle (displacement) of the rod 410 and the stress in the rotation direction are used as a measure of the degree of rotation, so that the ground torque measurement unit 422 provided on the ground and the in-hole rotation measurement provided on the upper portion of the outer tube 401 are measured. By measuring with the part 412, the torsional error of the rod 410 which changes with the depth can be corrected. In addition, regarding the in-hole rotation measuring unit 412 and the water pressure measuring unit 414, the battery type is used for the power source, and the data recording and transmission by the timer operation is convenient for the transmission of the digital signal.

  The hole bottom shear test can be repeatedly performed on the bottom of fresh ground rock at an arbitrary depth. In such a case, the excavation is stopped immediately before the start of the test, and the suspended bubble water used for excavation is allowed to flow. Wash the slime at the bottom of the hole. In addition, mud water gives lubricity, and slime is useless because it causes the blow-up and settling near the bottom of the hole. After the cleaning, c and φ can be obtained by adjusting to a predetermined (rod weight adjustment) supply pressure and increasing or decreasing the rotational force, and the uniaxial compressive strength is obtained from the excavation speed at a constant vertical load and rotational speed. I can do it. At the end of excavation, oil is used as a negative pressure transmission medium, the tensile force is transmitted to the rod 410, and the core is collected by the core catcher 406 that is provided on the inner surface of the bit 402 and can smoothly rotate independently. Thereby, the stress required for the tensile cutting of the core 405 self-supported from the borehole bottom ground rock, that is, the tensile strength of the ground rock is measured. The core catcher 406 is provided so as to protrude from the inner surface of the bit, and allows the core to advance in the inner tube 404 during excavation and holds the core when not excavating.

  In this way, the bottom shear strength measurement subsystem 400 can perform in-situ in-situ ground tests from sedimentary soil to soft rock and hard rock. Enables economic geological surveys. In addition, this sub-system eliminates the need for rock testing and sketching in horizontal shafts. Note that the usable limit of this subsystem is about GL—about 1500 m, and the applicable limit of the rod diameter is about φ116 mm. The hole bottom shear strength measurement subsystem 400 uses the same special shape diamond bit as the use of a special all-core sampling bit and can dig regardless of whether it is hard rock or soft rock. . Moreover, the excavation apparatus used for the hole bottom shear strength measurement subsystem 400 may be an ordinary excavator if the excavation pressure (supply pressure) can be controlled by hydraulic pressure and has a margin with respect to the planned excavation depth. In addition, by changing the use conditions of the suspended bubble water generator, not only boring but also all-core collection, wire line digging with vinyl sleeve and core collection are possible.

  The hole bottom shear strength measurement subsystem 400 includes a drilling device, a rotational force / digging pressure transmission rod 410 and a ground torque measuring unit 422 that can be attached thereto, and a bottom bottom shear test with a leading digging portion at the underground tip of the rod 410. An inner tube 404 equipped with a specially designed bit 402 and a core catcher 406 having a working surface is provided. Inside the inner tube 404, a water pressure measurement unit 414 that performs water pressure measurement and AD conversion recording, and torque measurement on the crown of the cone In addition, an in-hole rotation measuring unit 412 that performs digging pressure measurement and tensile stress measurement is mounted. It should be noted that the bit 402 can be switched to not only a diamond bit but also all-core sampling by metal bit, non-core excavation, etc. at any time according to the soil and lithology (similar to water for advancement).

  The core collection subsystem 200 digs the suspended bubble water up to a predetermined depth to the borehole used for digging, stops the digging once, and uses the function of automatically removing the suspended bubble water slime, And immediately start the hole bottom shear test. After completion of the hole bottom shear test, with the special spindle for hole bottom shear test attached, the drilling was continued while collecting all cores, and when the rod was pulled up at the end of the drilling, it was built in the inner tube 404. The core 405, which is self-supporting from the hole bottom by the action of the core catcher 406 and normally protected in the vinyl sleeve 408, is pulled upward, and an approximate number of tensile strengths in the original position of the core 405 can be obtained. it can. Data is provided from the core 405 obtained in the state of being accommodated in the vinyl sleeve 408 by observation of the situation immediately before and after the shear test. The bottom shear test by the bottom shear strength measuring subsystem 400 is different from the horizontal shaft lock shear test, and there is no vibration and time slack due to cutting and polishing of the specimen lock. And it can be repeated economically.

The hole bottom shear strength measurement subsystem 400 can measure / analyze and measure the maximum stress for soft rocks and clayey soils, and measure the maximum stress for hard rocks. Applicable to various ground rocks. It is possible to measure and analyze sedimentary soil, soft rock, and hard rock using the same excavation device, and repeat it at any depth from the surface layer to about 1000m below the ground, and on the way from the bottom of the hole to the ground surface. It is possible to automatically measure, compensate, and analyze pressure loss, stress relaxation and signal attenuation due to torsion of the rod. Further, this bit 402 is characterized by the fact that the small-diameter bit portion at the tip can collect all cores in the same manner as the double core tube (no rotational stress is generated even if a vinyl sleeve is used). When a self-supporting core is lifted from the ground rock held by the core catcher 406 provided in the base, it is possible to measure the approximate number of tensile stresses. You can get about the rocks. However, since the hole bottom shear strength measurement subsystem 400 alone is limited to a pinpoint investigation with respect to the planar spread regarding the rock mass characteristics, implementation with a plurality of holes increases the effect. .
[In-hole horizontal loading test subsystem]
The in-hole horizontal loading test subsystem 500 includes a plurality of cells maintained at an equal pressure, a displacement meter for measuring the amount of hole wall displacement, and the like, and performs a horizontal loading test.

  The configuration of the in-hole horizontal loading test subsystem 500 will be described with reference to FIG. The subsystem 500 includes a multi-measurement cell 502 group with a built-in pressure sensor / AD converter, a sensor unit composed of a shift meter 506 group, a water supply / drainage unit 508 equipped with a pressure gauge, a valve, and the like, and a sensor unit. And a measurement record control unit 512 that controls and manages the water supply / drainage unit 508. The cell 502 contains a pressurized medium transmitting substance (water or oil) and is kept at an equal pressure. The cell 502 includes a pressure measurement sensor and a power source / signal transmission device.

  Further, both ends of each cell 502 are bowl-like and elastic, for example, are made of metal or the like and are tightened and protected by a jig 502a for tracking the deformation of the hole wall, and depending on the degree of pressure supply, the deformation of the ground / soft rock / rock Each cell 502 can follow the deformation according to the degree of consolidation of the sandwiched object in the crack (fracture zone) independently and with high accuracy. Easy point correction. Note that the sensor unit is collected while being gradually drained by the drain pump of the water supply / drainage unit 508 while paying attention to the pressure balance near the ground after the measurement is completed.

  Further, the horizontal loading test subsystem 500 in the hole includes an AD converter 504 that digitizes measurement values obtained from each cell 502 alternately and on time, an armored cable 510 for inserting and removing the cell 502 into the borehole, and the like. A display device that includes a recording unit 512 that records the received signal on the ground with a recording device (which also serves as power supply, pressure transmission, and measurement signal recovery) and outputs an image at a preset time interval (Not shown). By the horizontal loading test subsystem 500 in the hole, each test cell 502 receives a uniform pressure, and the pressure and the deformation characteristics of the test cell hole wall surface are measured for each hole wall (layer) to which each test cell 502 is pressed. Can be measured. The deformation characteristics are a deformation coefficient, a yield pressure, and an ultimate pressure.

  The measurement operation procedure of the in-hole horizontal loading test subsystem 500 will be described below. A sensor unit coupled to the water supply / drainage unit 508 and the measurement / recording control unit 512 is suspended from the armor cable 510 and installed at a predetermined depth in the borehole while being balanced with the hydraulic head pressure. The pump 508 supplies water while recording the change of the displacement meter 506 in the sensor unit. A zero-point interpolated value (from the mode value) regarding the breakthrough of the plurality of variometers 506 is obtained. By obtaining the water supply pressure of each cell 502 included in the sensor unit and the measured value of the displacement meter 506, the deformation characteristics of the ground rock mass to be pressed can be measured.

The horizontal loading test subsystem 500 enables horizontal loading tests even for low-consolidated gouge layers (clayous strata containing active fault crushed rock fragments) generated by past active fault activity. It becomes. Note that the depth of use of the in-hole horizontal loading test subsystem 500 is about surface layer to GL—about 1500 m.
[Borehole TV Subsystem]
The borehole TV subsystem 600 applies the borehole TV (optical method) to the hole wall obtained by the suspended bubble water boring of the core collection subsystem 200, and confirms the geological structure by measuring, recording, and analyzing the hole wall. .

  After excavation with suspended bubble water by the core collection subsystem 200, all cores are collected and analyzed by the vertical boring method and the oblique excavation method shown in FIG. 3, or oblique excavation is featured by the suspended bubble water method. A plurality of boring holes with hole walls are determined and arranged in a systematic direction. Then, observation, recording, and analysis by the borehole television subsystem 600 are applied to these.

  As a result, the results of high-quality all-core sampling and core analysis analysis by the oblique excavation method confirm the survey results by the vertical boring method, improve the accuracy of the survey, and also by the combined surface wave exploration by the S-wave structure exploration subsystem 100 By comprehensively analyzing the results together with the measurement and analysis results, it is possible to detect the presence of buried faults, inconsistent surfaces, slip surfaces, etc., further selecting and confirming candidate sites and excavating to the facility installation base surface After that, geological confirmation (sketch) and rock mass test will be performed on the rock surface just above and below the basement.

  The borehole television subsystem 600 can eliminate the need for the rock test and sketch (experimental mine investigation test) in the horizontal shaft, which has been indispensable in the past, by executing the continuous recording / automatic analysis function of the borehole television.

  By using the borehole TV subsystem 600, it is possible to obtain a three-dimensional grasp of faults, slip planes, and misalignment planes that are difficult to detect from the surface layer that is upright or obliquely crossed with the ground, and the potential crack planes. Enables direct detection and confirmation. For the collected core, it is possible to obtain data with higher accuracy than the conventional method for core analysis, laboratory mechanical test, water permeability test, latent crack analysis, and the like.

  The borehole television subsystem 600 performs continuous recording / analysis of hole wall development images, and performs a flexible, economical in-situ test from the ground surface in place of a side pit test / sketch at an arbitrary depth. In addition, as an implementable depth, it is applicable to about GL-1500m.

Continuous recording and analysis by the borehole TV subsystem 600 may be performed not only in the vertical boring hole but also in the boring hole at a horizontal or near-inclined angle by the control boring, and this operation is performed on the ground directly under the existing main structure. It can also be carried out in bedrock, and at that time, it is possible to carry out orientation-oriented core sampling.
[Multi-element data integration subsystem]
The multi-element data integration subsystem 700 converts the data obtained from each of the subsystems 100 to 600 into a database as multi-dimensional three-dimensional data and analyzes it as three-dimensional geological / hydrological data (groundwater flow direction flow velocity / trajectory line). Display as direction / cross-section image.

  The multi-element data integration subsystem 700 makes it possible to analyze and image a step-like geological structure that has been difficult to obtain by three-dimensional analysis and imaging of these data, and to flow the specific direction groundwater flow velocity Enables analysis and imaging of the distribution. The multi-element data integration subsystem 700 integrates each measurement value obtained from each subsystem, analyzes them in a three-dimensional or four-dimensional (including time series), and performs image processing. From any cross-section to 3D and 4D images.

  Previously, it was obtained as various test data such as geology, rock formation, soil, etc., laboratory test data, and S-wave structure data by measuring methods that can only be displayed in two-dimensional section for each layer. The surface and inconsistency surface could not be accurately estimated / confirmed, and it was limited to image formation based on individual interpretation by experts.

  However, in the multi-element data integration subsystem 700, the S wave structure data obtained by the S wave structure exploration subsystem 100 is taken into the database. However, with only the S wave structure data, despite the improvement in efficiency and accuracy of the S wave structure exploration subsystem 100, smoothing is applied due to the resolution limit of the exploration method and complementary analysis characteristics. There are places where it is difficult to match the common sense of geological experts regarding the sharpness and resolution of inconsistencies.

  Therefore, clear measurement data related to underlying faults, slip surfaces, and inconsistencies characterized by soil lithologic analysis data by analysis of cores collected by drilling combined with vertical and oblique excavation by the core collection subsystem 200 is obtained. Import into the database of the integrated subsystem 700. It should be noted that the core collection subsystem 200 alone enables accurate data confirmation regarding acute buried faults, slip planes, and misalignment planes that cannot be seen from the ground, but strike inclination is only an estimate.

  Next, a lot of measurement data on strike slopes related to each underlying fault, slip surface, and misalignment by borehole TV (performs automatic data recording analysis) in the borehole TV sub-system 600 borehole and borehole combined borehole. Import into the database of the element data integration subsystem 700. Note that only the borehole television subsystem 600 provides information on the strike and inclination of the specific strata, but it is only an estimate for hydraulics and hydrology.

  Furthermore, using the JFT measurement subsystem 300, the data set in three-dimensional coordinates of the spring pressure and hydraulic conductivity measured by the JFT measurement characterized by multi-stage packers in the specific crack and strata in the vertical and oblique drilling boreholes. To the database of the multi-element data integration subsystem 700. Note that the JFT measurement subsystem 300 alone is not sufficient for hydraulic and hydrological analysis.

  The multi-element data integration subsystem 700 performs the smoothing process on the three-dimensional interrelationship of the data obtained from each subsystem by the multiple average method, thereby obtaining the data of each borehole in the core collection and the S wave structure. 3D data, data obtained by borehole television, and hydrological data are superimposed and analyzed. This complements the weaknesses of each method (the sharp changes in the formation are expressed on average), which helps detect hidden faults. From the stratum surface of the core, only the strike direction is known. In addition, it is more reliable and more realistic by expressing a slip surface that was difficult to determine because it is difficult to distinguish it from the false layer, etc. A close image (small error from the analysis calculation result) can be obtained.

  The multi-element data integration subsystem 700 re-analyzes the data groups obtained from each subsystem and obtains them as a plurality of orthogonal or oblique data groups (preferably in a grid-like arrangement). A comprehensive database having data groups (data of different personalities) belonging to spatial coordinates (four dimensions if time is included) is constructed. The three-dimensional distribution of pore water pressure and hydraulic conductivity obtained by multiple boreholes not only gives the three-dimensional flow velocity of groundwater, but can also be imaged and shown with other data as a trajectory or flow velocity distribution. .

  In-situ survey information based on ordinary exploration and construction methods for narrowing down the main building ground contact candidate areas is not only useful, but by incorporating such information into the multi-element data integration subsystem 700, the analysis accuracy is further improved. Rise. In addition, this invention does not exclude the survey data in the site by the conventional exploration method or the ordinary construction method (Shimizu digging) boring and logging. Furthermore, the present invention can also investigate the geological structure directly under the support base of existing structures.

  In the conventional three-dimensional imaging system, from the database of independent elements, in each data processing, the equivalent data is analyzed as a continuous equivalent curved surface and complemented to display based on the estimated value, and smoothed by a computer. Since the process is performed, the intrinsic discontinuity surface is only estimated from a sudden inflection position (by human intervention called an expert) (in the reflection S-wave structure analysis, finally, human interpretation) Therefore, it is highly dependent on the experience and interpretation of engineers who interpret images, and for the inconsistency of interest, a large number of boreholes (normal “group” Surveys (such as row boring) were required (such surveys are not allowed as the base survey of the main structure will damage the support base).

  The multi-element data integration subsystem 700 according to the present invention can reduce such uncertainty. That is, in the database of the S-wave structure exploration subsystem 100, the analysis data of the core obtained by the boring method characterized by the oblique excavation of the core collection subsystem 200, and the stratigraphy, hydraulics and hydrology obtained from the laboratory test data Related to the data, observation data from the borehole TV subsystem 600 in the borehole, and the stratigraphy, hydraulics and hydrology in the borehole logging, interstitial water pressure measurement, in situ hydraulic conductivity measurement, etc. The groundwater flow direction flow velocity is analyzed by estimating and calculating the total flow direction flow velocity in a specific formation or groundwater from the data to be obtained.

  The multi-element data integration subsystem 700 that analyzes the flow direction flow velocity of groundwater does not use a tracer, and also provides highly reliable flow direction / velocity information, three-dimensional display of trajectory lines, and pumping environment associated with construction of large-scale facilities. It can be used for pre-analysis such as impact assessment and planning of measures based on monitoring data.

  The multi-element data integration subsystem 700 constructs a database of three-dimensional data, performs three-dimensional imaging, and analyzes the data, thereby identifying the geological structure related to the foundation of the main structure, particularly the fault and slip surface. Data can be obtained. Therefore, it is possible to evaluate the reliability of the support base (by the Terzaggy method) based on primary / secondary consolidation (creep characteristics) and fault / slip slip surface information (confirmation that it does not exist) as long-term ground stability evaluation.

  The multi-element data integration subsystem 700 enables geological structure, mechanical characteristics of main structures, layout design data of seismic S wave structure exploration subsystem and core collection subsystem, long-term stability evaluation, and excavation (open After cutting), it will be possible to conduct a full-scale geological survey on the foundation by an expert. This method was sketched superficially in a limited space in the tunnel in the horizontal shaft survey that has been carried out in the past, but since it can be performed on the excavated installation base surface, it has excellent quality information and Provide economic improvement.

  In addition, the conventional horizontal shaft shear test for confirming laboratory tests is easy to make a minor change in the position of the main building installation, and can be implemented on the constructed installation base surface. Economical improvement is possible. Since the combined exploration / investigation / three-dimensional imaging system of the present invention is excellent in economic efficiency and mobility, it is possible to compare two candidate points that have been given up in the past (especially underlying faults and slip surfaces).・ In terms of long-term stability evaluation).

  In addition, the multi-element data integration subsystem 700 combines information on the ground, bedrock, etc. based on the above-mentioned exploration / measurement and all-core sampling / analysis / test results, and in-situ permeability tests / water level observations, etc., to be performed separately, When the three-dimensional display is performed by the multi-element data integration subsystem, the flow direction flow velocity can be analyzed.

1 Geological structure in-situ survey system 100 S-wave structure exploration subsystem 200 Core sampling subsystem 300 JFT measurement subsystem 400 Hole bottom shear strength measurement subsystem 500 In-hole horizontal loading test subsystem 600 Borehole TV subsystem 700 Multi-element data integration sub-system

Claims (22)

A geological structure survey system,
A wave structure exploration subsystem that explores geological structures by measuring Rayleigh and reflected waves;
A core collection subsystem that drills the borehole using suspended bubble water to form the borehole and collect the core;
A JFT measurement subsystem that measures spring water pressure (JFT) with a water-impervious type packer to measure geological hydrology,
Hole bottom shear strength measurement subsystem for measuring the strength of geology by performing hole bottom shear at the bottom of the borehole washed with the suspended bubble water;
An in-hole horizontal loading test subsystem for performing a horizontal loading test in the borehole;
An in-hole imaging subsystem for imaging the borehole;
A geological structure survey system comprising a multi-element data integration subsystem that performs three-dimensional analysis of geology using multi-element data obtained by each of the subsystems. The geological structure survey system according to claim 1, wherein the S-wave structure exploration subsystem includes a plurality of arrays arranged at each vertex of a grid set on the ground surface in order to measure the Rayleigh wave and the reflected wave. Equipped with a geological structure survey system. The geological structure survey system according to claim 2, wherein the array is composed of a plurality of receivers arranged at predetermined intervals. The geological structure survey system according to claim 1, wherein the core sampling subsystem includes a vertical moat and / or oblique core sampling device. The geological structure investigation system according to claim 1, wherein the multi-stage packer of the JFT measurement subsystem includes an upper multi-stage packer disposed above the measurement site and a lower multi-stage packer disposed below the measurement site. Constructed geological structure survey system. The geological structure investigation system according to claim 5, wherein the upper multistage packer and the lower multistage packer are a plurality of packers. 2. The geological structure survey system according to claim 1, wherein the hole bottom shear strength measuring subsystem has a conical crown that leads the excavation and secures a shear surface, and applies a rotational force while holding the core during excavation. A geological structure survey system comprising a core lifter for ensuring that the core is lifted by shearing the core from the bottom of the hole. 2. The geological structure inspection system according to claim 1, wherein the in-hole horizontal loading test subsystem measures a plurality of cells that measure pressure due to pressure feeding in the boring hole, and a transition of a boring hole wall due to a contacted cell. A geological structure survey system that measures the pressure and displacement of a borehole wall in multiple ways by providing a plurality of displacement meters. The geological structure investigation system according to claim 8, wherein the plurality of cells of the in-hole horizontal loading test subsystem each include a deformation follower for causing the plurality of cells to follow deformation of the hole wall. system. The geological structure survey system according to claim 8, wherein the cells have elasticity and pressure is transmitted to each other. 2. The geological structure survey system according to claim 1, wherein the multi-element data integration subsystem records the multi-element data obtained by each of the subsystems, and analyzes and uses the multi-element data as a three-dimensional image. Display, geological structure survey system. A geological survey method,
S-wave structure exploration process for exploring geological structure by measuring Rayleigh wave and reflected wave;
A core collecting step of excavating a borehole using suspended bubble water and collecting a core;
A JFT measurement process in which a spring pressure test (JFT) is performed by a multipacker to measure water quality hydrology,
Hole bottom shear strength measurement step of measuring the strength of the geology by performing hole bottom shearing at the bottom of the borehole washed with the suspended bubble water,
In-hole horizontal loading test process for performing a horizontal loading test in the boring hole,
In-hole photographing process for photographing the inside of the boring hole;
A geological structure investigation method comprising: a multi-element data integration step of performing a three-dimensional analysis of the formation using the multi-element data obtained in each step. 13. The geological structure investigation method according to claim 12, wherein the S-wave structure exploration step includes a plurality of arrays arranged at each vertex of a grid set on the ground surface in order to measure the Rayleigh wave and the reflected wave. , Geological structure survey method. The geological structure investigation method according to claim 13, wherein the array is composed of a plurality of receivers arranged at predetermined intervals. 13. The geological structure investigation method according to claim 12, wherein the core collecting step includes a vertical moat and / or an oblique core collecting device. 13. The geological structure investigation method according to claim 12, wherein the multi-stage packer of the JFT measurement step is composed of an upper multi-stage packer arranged above the measurement site and a lower multi-stage packer arranged below the measurement site. The geological structure survey method. The geological structure investigation method according to claim 16, wherein the upper multistage packer and the lower multistage packer are a plurality of packers. 13. The geological structure survey method according to claim 12, wherein the hole bottom shear strength measuring step includes a core catcher that shears the core from the hole bottom by rotating and loading while holding the core during non-digging. Geological structure survey method to measure 13. The geological structure inspection method according to claim 12, wherein the in-hole horizontal loading test step includes a plurality of cells for measuring pressures in the borehole and the measurement cell, and a plurality of displacement meters for measuring displacement of the borehole wall. The geological structure investigation method which measures the pressure and displacement of a boring hole wall in multiple ways. The geological structure investigation method according to claim 19, wherein the plurality of cells in the in-hole horizontal loading test step each include a deformation follower for causing the plurality of cells to follow deformation of the hole wall. . 21. The geological structure survey method according to claim 20, wherein the position holding tool is bowl-like and elastic, and is attached around the cell. 13. The geological structure investigation method according to claim 12, wherein the multi-element data integration step records the multi-element data obtained in each step and displays the multi-element data as a three-dimensional image using the multi-element data. Structural survey method.

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