JP5839273B2 - In-situ test method and in-situ test apparatus - Google Patents

Description

  The present invention relates to an in-situ test method and an in-situ test apparatus for evaluating chemical effects of support in a geological disposal facility.

  FIG. 1 is a schematic diagram showing a nuclear fuel cycle. As shown in FIG. 1, high-level radioactive waste that has been treated at the reprocessing plant F1 and is no longer usable is stored for a certain period in the high-level radioactive waste storage facility F2, and then disposed of in geological formation. Thus, the facility for geological disposal of high-level radioactive waste is the geological disposal facility F3.

  FIG. 2 is a conceptual diagram showing a geological disposal facility. As shown in FIG. 2, the geological disposal facility F3 includes a ground facility S1 and an underground facility S2. The underground facility S2 includes a tunnel group T, and a shaft T1 or a slope (not shown) for accessing the tunnel group T from the ground facility S1. The tunnel group T is provided in a width of several km square, and the tunnel extension is assumed to extend over several hundred km. In Japan, it is stipulated by law that the tunnel group T be an underground facility deeper than 300 m.

  In this geological disposal facility F3, technical examinations and plans related to the construction and disposal of the underground facility S2 are being conducted in the country and related organizations for the rock types targeting hard rock and sedimentary soft rock.

  By the way, the cementitious material used for shaft support and grout reacts with groundwater to make the surrounding environment of the tunnel a highly alkaline environment. This highly alkaline environment chemically affects the bentonite used for buffer materials and backfilling and surrounding rock mass (bentonite and rock mass alteration), and the resulting mechanical performance degradation and degradation (decrease in strength and stiffness) It has been pointed out that hydrological / mass transfer characteristics may change (for example, see Non-Patent Document 1). For this reason, low-alkaline shotcrete and methods for constructing tunnels that minimize the amount of cement used have been studied and developed (for example, see Patent Document 1).

  At the next stage of development, it is required to evaluate the results obtained in the past research and development in situ.

Japanese Patent No. 4356252

"Technical reliability of geological disposal of high-level radioactive waste in Japan-Geological disposal research and development second summary-Volume 2 Engineering technology of geological disposal" Nuclear Fuel Cycle Development Organization, November 26, 1999, p. IV-220

  However, the results obtained through research and development depend on the geological environment such as the surrounding rock mass and groundwater conditions, and accurate evaluation is difficult unless the influence of the geological environment is controlled.

  This invention is made in view of the above, Comprising: It aims at providing the in-situ test method and in-situ test apparatus which can control the influence of the change of geological environment, such as the surrounding rock mass and the state of groundwater .

  In order to solve the above-described problems and achieve the object, the present invention is an in-situ test method for evaluating the chemical effect of a support installed in a tunnel, from the inner space side to the ground side of the tunnel. By excavating into a cylindrical shape, and filling the cylindrical void formed by excavation with a non-cement-based material, the support and the rock at a predetermined depth are isolated from the peripheral support and the surrounding rock, and the gap in the isolated rock The water pressure is measured and the water flowing in the isolated rock is collected.

  Moreover, the present invention is characterized in that, in the above invention, water is collected from a plurality of positions in the depth direction of the isolated rock mass.

  Further, in the present invention, in the above invention, a pressure vessel having an internal space facing an isolated support is provided on the inner space side of the tunnel, and measurement is performed at the deepest part of the isolated rock mass toward the support isolated from the pressure vessel. The water having the same water pressure as the pore water pressure is supplied.

  Further, in the present invention, in the above invention, a pressure vessel having an internal space facing an isolated support is provided on the inner space side of the mine shaft, water of a required pressure is supplied to the pressure vessel, and the flow assumed for the isolated bedrock It is characterized by providing a place.

  Further, the present invention is characterized in that, in the above invention, after a required period has elapsed, the isolated support and the rock mass are over-cored, and a core specimen including the support and the rock mass in contact with the support is collected. .

  Further, the present invention provides a peripheral support for a support and a bedrock of a predetermined depth by filling a non-cement-based material into a space formed in a cylindrical shape from the inner space side to the natural ground side of the tunnel where the support is laid. Is an in-situ test apparatus that is isolated from the surrounding rock mass and used to evaluate the chemical effect of the support in the isolated rock mass, and measures the pore water pressure in the isolated rock mass and collects the water flowing in the isolated rock mass It is characterized by comprising a water sampling pipe and a pressure vessel which is inserted and fixed from the inner space side of the mine shaft to the natural ground side so as to surround the isolated support and the rock, and the inner space faces the isolated support.

  The in-situ test method according to the present invention excavates in a cylindrical shape from the inner space side of the tunnel toward the natural ground side, and fills the cylindrical void formed by the excavation with a non-cement material, thereby supporting and The rocks of a given depth are isolated from the surrounding support and the surrounding rocks, and the pore water pressure in the isolated rocks is measured, and the water flowing in the isolated rocks is collected, so changes in the geological environment such as the surrounding rocks and groundwater conditions You can control the impact. Thereby, according to the in-situ test method concerning the present invention, the chemical influence of the support installed in the tunnel can be evaluated accurately.

  The in-situ test apparatus according to the present invention measures the pore water pressure in an isolated rock mass, collects water flowing in the isolated rock mass, and surrounds the isolated support and rock mass from the inside of the mine shaft to the ground. It is equipped with a pressure vessel that is inserted and fixed on the mountain side and has an internal space facing an isolated support, so it is possible to control the influence of changes in the geological environment such as surrounding rock mass and groundwater. Thereby, according to the in-situ test device concerning the present invention, the chemical influence of the support installed in the tunnel can be evaluated accurately.

FIG. 1 is a schematic diagram showing a nuclear fuel cycle. FIG. 2 is a conceptual diagram showing a high-level radioactive waste embedding disposal facility. FIG. 3 is a schematic diagram showing a test tunnel using the in-situ test method and the in-situ test apparatus according to the embodiment of the present invention in relation to the test access tunnel. FIG. 4 is a cross-sectional view showing a cross-section of the test mine shown in FIG. FIGS. 5-1 is sectional drawing for demonstrating the in-situ test method which is embodiment of this invention, Comprising: It is a figure which shows the test mine used as object. 5-2 is sectional drawing for demonstrating the in-situ test method which is embodiment of this invention, Comprising: It is a figure which shows the state dug cylindrically toward the natural ground side from the inner space side of a tunnel. is there. FIG. 5-3 is a cross-sectional view for explaining the in-situ test method according to the embodiment of the present invention, and shows a state in which a non-cement-based material is filled in a cylindrical gap generated by excavation. is there. 5-4 is sectional drawing for demonstrating the in-situ test method which is embodiment of this invention, Comprising: It is a figure which shows the state which excavated the boring hole toward the natural ground side from the inner space side of a tunnel. is there. FIG. 5-5 is a cross-sectional view for explaining the in-situ test method and the in-situ test apparatus according to the embodiment of the present invention, and shows a state in which a container having an internal space facing an isolated bedrock is installed. It is. 5-6 is sectional drawing for demonstrating the in-situ test method and in-situ test apparatus which are embodiment of this invention, Comprising: It is a figure which shows the state which inserted the water sampling pipe | tube. FIG. 6 is a diagram showing an example in which high-strength shotcrete is adopted for the support. FIG. 7 is a diagram showing an example in which low alkali shot concrete is adopted for support.

  Embodiments of an in-situ test method and an in-situ test apparatus according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the examples shown in the embodiments.

  FIG. 3 is a schematic diagram showing a test tunnel using the in-situ test method and the in-situ test apparatus according to the embodiment of the present invention in relation to the test access tunnel, and FIG. 4 is a test tunnel shown in FIG. It is sectional drawing which shows no cross section.

  The in-situ test method and in-situ test apparatus according to the present embodiment evaluates the chemical effect of the support M installed in the mine shaft, and is similar to the Horanobe underground facility of JAEA (Japan Atomic Energy Agency). Targeted for geological disposal facilities in soft rocks.

  In the in-situ test method according to the present embodiment, as shown in FIG. 3, the test tunnel GT constructed by branching from the test access tunnel GA is used as the original position. The test tunnel GT is provided with a fixed section A1 in which a support M1 having a structure to be evaluated is constructed and a fixed section A2 and A3 in which supports M2 and M3 having a structure to be compared are constructed. In the example shown in the present embodiment, a support constructed with a segment using rock and suppressing the amount of cement used as much as possible (hereinafter referred to as “segment using rock”) is defined as a support M1 having a structure to be evaluated. Supports constructed with high-strength shotcrete and supports constructed with low alkali shotcrete are designated as supports M2 and M3. In addition, as shown in FIG. 5-1, the rock-use segment constituting the support M1 is integrated with the steel frame b by filling the rock a composed of granite or the like into the steel frame b. Therefore, cement mortar c is filled between the rock a and the rock a. Further, the support M1 constructed by the rock-use segment is backed up by using the crushed stone d or the like on the natural ground E side of the segment, while the test tunnel GT side of the segment is covered with the steel plate of the steel frame b.

  In the example shown in FIG. 3, from the test access tunnel GA toward the back of the test tunnel GT, the support M2 of the structure to be compared, the support M1 of the structure to be evaluated, and the support M3 of the structure to be compared are respectively shown. Lay out certain sections A2, A1, and A3. Specific examples include support M2 constructed with high-strength shotcrete (see FIG. 6), support M1 constructed with a rock-use segment (see FIG. 5), and support M3 constructed with low alkali shotcrete (FIG. 7). )), Respectively. The support M (M1 to M3) laid from the test access tunnel GA toward the back of the test tunnel GT is not limited to this order, and may be laid in any order.

  FIG. 5 is a cross-sectional view for explaining the in-situ test method and in-situ test apparatus according to the embodiment of the present invention. Here, an in-situ test method in which the section A1 in which the support M1 constructed by the rock use segment is laid is used as an in-situ explanation will be described. As shown in FIG. 5, the in-situ test method and in-situ test apparatus 1 according to the embodiment of the present invention excavate in a cylindrical shape from the inner space side of the test tunnel GT toward the natural ground E side. By filling the non-cement material P into the cylindrical gap D formed by the above, the supporting MA and the rock E1 having a predetermined depth are isolated from the peripheral supporting MB and the surrounding rock E2, and the pore water pressure in the isolated rock E1 is reduced. While measuring, the water which flows into the isolated bedrock E1 is extract | collected.

  First, as shown in FIG. 5B, after removing the steel plate (steel frame b) in the required range, a predetermined diameter and a predetermined depth from the inner side of the test tunnel GT toward the ground E side. Are excavated in a cylindrical shape so that the support MA and the bedrock E1 remain in the center. The predetermined diameter is, for example, about 10 cm to 20 cm, and is set the same for the support M1 of the structure to be evaluated and the supports M2 and M3 of the structure to be compared. The predetermined depth is, for example, about 1 m, and is set the same for the support M1 of the structure to be evaluated and the supports M2 and M3 of the structure to be compared. For excavation, a cylindrical tool K having a tip for excavating the support M and the rocks E1 and E2 is used. As a result, cylindrical gaps (grooves) D are formed in the support M and the rocks E1 and E2.

  Next, as shown in FIG. 5-3, a non-cement-based material P is filled into a cylindrical gap D formed by excavation. The non-cement-based material P is, for example, a material such as urethane resin, epoxy resin, acrylic resin, or silica resin, and uses a water shielding material that has a small chemical effect on the rock mass E1. Further, the filling of the non-cement system material P is performed from the back side of the space (the ground E side) to the front side (inside air side) so that the space D does not remain. As a result, the support MA and the rock E1 having a predetermined depth are isolated from the peripheral support MB and the peripheral rock E2. The non-cement material P may be filled with the cylindrical tool K left in the excavated cylindrical gap D. Further, a cylindrical metal pipe (for example, a steel pipe) may be inserted into the excavated cylindrical gap D, and then the non-cement material P may be filled. Further, a cylindrical metal pipe (for example, a stainless steel pipe) having a thickness smaller than the thickness of the tool K is inserted into the excavated cylindrical gap D, and thereafter, the non-cement material P is filled. Good. Alternatively, a cylindrical tube having a thickness smaller than that of the tool K may be inserted when the cylindrical gap D is excavated, and the cylindrical tube may be left when the tool K is pulled out.

  Next, as shown in FIG. 5-4, a bored hole B having a required diameter is provided so that the centers coincide with the centers of the support MA and the rock mass E1 isolated from the peripheral support MB and the peripheral rock mass E2. The borehole B is used to measure the pore water pressure in the rock E1 isolated from the surrounding rock E2, and to collect water flowing in the rock E1 isolated from the surrounding rock E2, and more than the rock E1 isolated from the surrounding rock E2. It is the groundwater that flows in from deep places and the water that flows in from the support M side (supplied water).

  Next, as shown in FIG. 5-5, the inner space of the test tunnel GT is surrounded by the support MA and the rock E1 separated from the peripheral support MB and the peripheral rock E2, and is concentric with the cylindrical gap D described above. Excavate in a cylindrical shape from the side toward the natural ground E side. For excavation, a cylindrical tool K2 having a tip for excavating the support M and the rocks E1 and E2 is used. Thereby, the cylindrical tool K2 enters the support M and the rock masses E1 and E2. And this tool K2 is left behind and this tool K2 is diverted to a pressure vessel. The diameter of the tool K2 is, for example, about 30 cm, and the tool K2 having the same diameter is also used in the supports M2 and M3 having the structure to be evaluated. The excavation depth of the tool K2 is, for example, about 50 cm, and is set to the same excavation depth in the supports M2 and M3 of the structure to be evaluated.

  Then, a cement-based mortar (not shown) is filled in the gap generated by excavation with the tool K2 that has entered the rock masses E1 and E2 remaining. Thereby, the tool K2 is fixed in a state where the internal space faces the support MA that is separated from the peripheral support MB. The material used for fixing the tool K2 is not limited to cement-based mortar, and a material such as an epoxy resin may be applied.

  And the cylindrical tool K2 is used as the pressure vessel 2 by fixing a lid to the head of the cylindrical tool K2. The lid (pressure vessel 2) fixed to the base of the tool K2 is provided with a hole 21 through which the water sampling pipe 3 described later passes. In addition, a water injection pipe 22 is connected to the lid of the tool K2. The water injection pipe 22 is for supplying water of a desired pressure to the pressure vessel 2, and as described above, one end is connected to the lid fixed to the head of the tool K2, and the other end is a pump (not shown). Connect to.

  In the above-described example, the tool K2 is diverted to the pressure vessel 2, but the tool K2 is removed from the excavated cylindrical groove D2 having a predetermined depth, and a cylindrical pressure vessel is inserted separately. Good. Also in this case, the diameter and the insertion depth of the pressure vessel are set to be the same for the support M1 of the structure to be evaluated and the supports M2 and M3 of the structure to be compared.

  Next, as shown in FIG. 5-6, the water sampling tube 3 is inserted into the bore hole B through the hole 21 provided in the pressure vessel 2 (the lid fixed to the base of the tool K2). The water sampling pipe 3 measures pore water pressure in the support MA and the rock mass E1 isolated from the peripheral support MB and the peripheral rock E2, and collects water flowing in the support MA and the rock mass E1 isolated from the peripheral support MB and the peripheral rock E2. It has an outer diameter substantially the same as the diameter of the boring hole B, and a required length to the depth of the boring hole B (a length for projecting from the pressure vessel 2 to the inner space side of the test tunnel GT). have. The water sampling pipe 3 is divided into a plurality of sections in the depth direction by the packer 31, and a water sampling pipe (branch pipe (not shown)) is inserted into each section, and the pore water pressure is measured in each section. A sensor (not shown) is provided. Thereby, water can be collected for each section divided by the packer 31, and the pore water pressure can be measured for each section. Note that the water sampling pipe 3 may be divided at equal intervals in the depth direction as long as it can collect water at a desired position and measure the pore water pressure at the desired position. It may be a thing.

  Next, the pump is automatically controlled so that the water supplied to the pressure vessel 2 has a desired pressure. Thereby, the water pressure inside the pressure vessel 2 becomes a desired pressure. Here, the water supplied to the pressure vessel 2 is pure water or groundwater collected at the original position, but the groundwater collected at the original position is affected by the construction of the test tunnel GT (for example, grout). It must be not (not disturbed).

  And while measuring the pore water pressure in the bedrock E1 isolated from the surrounding rock mass E2, the inside of the test tunnel GT so that the water sampling pipe 3 which collects the water which flows into the separated rock mass, and the isolated support MA and the rock mass E1 may be enclosed. The pressure vessel 2 that is inserted and fixed to the natural ground E side from the inner space and faces the isolated support MA constitutes the in-situ test apparatus 1.

  By the way, the pressure (desired pressure) of the water supplied to the pressure vessel 2 is determined by the flow field assumed for the support MA and the rock mass E1 isolated from the peripheral support MB and the peripheral rock mass E2.

  For example, when it is assumed that the chemical effect (ion movement) from the support M to the rock mass E1 is caused by the diffusion of the matrix portion of the rock mass without generating a flow field in the rock mass E1, it was isolated from the surrounding rock mass E2. Water of pore water pressure measured at the deepest part of the bedrock E1 is poured. When the pore water pressure in the deepest part of the rock mass E1 isolated from the surrounding rock mass E2 is assumed to be the same as the initial pore water pressure in the rock mass (natural ground E) measured before constructing the test tunnel GT The initial pore water pressure may be poured.

  On the other hand, when it is assumed that groundwater flows from the bedrock E1 side to the support M side and the chemical influence (ion movement) from the support M to the bedrock E1 is mainly caused by the inflow of groundwater to the test tunnel GT Then, water of a required pressure is supplied so that groundwater of a predetermined flow rate flows through the bedrock E1. Specifically, based on the pore water pressure measured at the deepest part of the rock mass E1 isolated from the surrounding rock mass E2, the permeability coefficient of the rock mass and the permeability coefficient of the support M determined by the in-situ test or laboratory test, from the surrounding rock mass E2 It sets as a relative pressure with respect to the pore water pressure in the deepest part of the rock mass E1 isolated from the surrounding rock mass E2, so that the groundwater of a predetermined flow volume may flow through the isolated rock mass E1. In this case, the water pressure in the pressure vessel 2 is lower than the pore water pressure in the deepest part of the rock E1 separated from the surrounding rock E2.

  On the other hand, when it is assumed that water flows from the support M side toward the rock mass E1, and the chemical influence (ion movement) from the support M to the rock mass E1 is mainly caused by the outflow of water to the rock mass E1, Water of a required pressure is poured so that a predetermined flow rate of water flows through the bedrock E1. Specifically, the rock E1 is predetermined based on the pore water pressure measured at the deepest part of the rock E1 isolated from the surrounding rock E2, the permeability coefficient of the rock mass and the permeability coefficient of the support M obtained by the in-situ test or the laboratory test. Is set as a relative pressure with respect to the pore water pressure in the deepest part of the rock E1 isolated from the surrounding rock E2. In this case, the water pressure in the pressure vessel 2 is higher than the pore water pressure in the deepest part of the rock E1 separated from the surrounding rock E2.

  Next, the pore water pressure is measured at a predetermined time interval for each section and the groundwater is collected. And water quality (for example, pH, dissolved ions, etc.) is monitored for each section.

  Then, after the required period, specifically the period necessary for the in-situ test has elapsed, before the test tunnel GT is backfilled, the rock E1 isolated from the surrounding rock is over-cored, and the support M and the support M A core specimen including the bedrock E1 in contact with the rock and the bedrock deeper than that is collected. Then, chemical analysis and mechanical testing of the collected core specimen are performed. For the chemical analysis of the core specimen, various methods such as X-ray diffraction, thermal analysis, chemical composition analysis, pore measurement by mercury intrusion test, pore water ion analysis, etc. are used for the chemical composition changes of support M and bedrock E1. It is done. In addition to this, neutralization of the concrete used as the support M and changes in the rock a, cement / mortar c and steel plate (steel frame b) used in the rock-utilizing segment are also carried out. Furthermore, the chemical effect obtained from the analysis of the water quality of the groundwater collected at predetermined time intervals and the core specimen will be compared.

  Then, the chemical effect is evaluated using the support M1 constructed with the rock-use segment as an evaluation target, and the support M2 constructed with the high-strength shotcrete and the support M3 constructed with the low alkali shotcrete. Specifically, whether the chemical effect of the support M1 constructed in the rock-use segment on the rock mass E1 is less than the chemical effect of the support M2 constructed of high-strength shotcrete on the rock mass E1. It is evaluated whether or not the chemical influence exerted on the rock mass E1 by the support M1 constructed in the use segment is smaller than the chemical influence exerted on the rock mass E1 by the support M3 constructed by the low alkali concrete.

  And if it is evaluated that the support M1 constructed in the rock-use segment has less influence on the rock mass E1 than the support M2 constructed in the high-strength shotcrete, it is constructed in the rock-use segment from the viewpoint of chemical influence. The supported M1 is superior to the supported M2 constructed with high-strength shotcrete. Also, if it is evaluated that the support M1 constructed with the rock-use segment has less influence on the rock mass E1 than the support M3 constructed with the low alkali shot concrete, it is constructed with the rock-use segment from the viewpoint of chemical influence The supported M1 is superior to the supported M2 constructed of low alkali shot concrete. Even if the support M1 constructed with the rock-use segment has the same effect on the rock mass E1, the support constructed with the rock-use segment is equivalent to the effect of the support M3 constructed with low alkali shot concrete on the rock mass E1. Taking M1's strength and rigidity into account, it has the advantages that the excavation stability is excellent and the supporting pressure is small, so that the excavation cross section is small and the excavation soil volume is small. The support M1 constructed by use is superior to the support M3 constructed by low alkali shot concrete.

  The in-situ test method according to the embodiment of the present invention described above excavates in a cylindrical shape from the inner space side of the test tunnel GT toward the natural ground E side, and does not enter the cylindrical gap D formed by excavation. By filling the cement-based material P, the support MA and the rock mass E1 of a predetermined depth are isolated from the peripheral support MB and the peripheral rock mass E2, so that the influence of the geological environment such as the surrounding rock mass E2 and the state of groundwater can be controlled. it can. As a result, the test environment can be maintained in a stable state for a long period of time, and a chemical influence evaluation that requires a long period of time can be performed in a stable environment.

  Further, by controlling the pressure of the water supplied to the pressure vessel 2, it is possible to evaluate the chemical influence of the groundwater flow on the support M to be compared. Thereby, when the groundwater flows from the rock E1 side toward the support M side or when the groundwater flows from the support M side toward the rock E1 side, it is easy to evaluate the chemical influence exerted by the support M.

  Moreover, since the pressure of the water supplied to the pressure vessel can be the same as the pore water pressure of the rock mass E1 (the pore water pressure measured at the deepest part of the rock mass E1 isolated from the surrounding rock mass E2), a flow field is generated in the rock mass E1. You can artificially create a state without. Thereby, the situation by the diffusion of chemical species (dissolved ions) from the support M to the matrix of the rock E1 can be grasped.

  Furthermore, since the groundwater flow field can be controlled, it is possible to shorten the time required for evaluating the chemical effects associated with the flow of groundwater by increasing the flow of groundwater. If the period required for evaluation is shortened, an economic effect can be obtained.

  Moreover, since the tool K2 to be diverted to the pressure vessel 2 is fixed by filling the gap formed by the tool K2 diverting to the pressure vessel 2 with the cement-based mortar, even if a high pressure acts on the pressure vessel 2, The pressure vessel 2 does not come off.

  Further, by filling the cylindrical gap D with non-cement system, the support MA and the rock mass E1 isolated from the peripheral support MB and the peripheral rock mass E2 eliminate the influence of the inflow of groundwater from the peripheral support MB and the peripheral rock mass E2. it can. In addition, the influence of cement-based mortar used for fixing the pressure vessel 2 can be eliminated. By reducing the effects of construction and other tests, the test environment can be maintained in a stable state for a long period of time, and a test over a long period of time can be performed in an environment where the chemical effect evaluation is stable.

DESCRIPTION OF SYMBOLS 1 In-situ test apparatus 2 Pressure vessel 21 Hole 22 Injection pipe 3 Sampling pipe 31 Packer A1, A2, A3 section B Boring hole D Cavity D2 Groove E Jiyama E1 Rock (isolated bedrock)
E2 Peripheral rock mass F3 Geological disposal facility GA Test access tunnel GT Test tunnel K tool K2 tool M support M1 Support built in the segment using rock (support of structure to be evaluated)
a rock b steel frame c cement mortar d crushed stone M2 Support constructed with high-strength shotcrete (support for the structure to be compared)
Support constructed with M3 low alkali shotcrete (support for the structure to be compared)
MA support (isolated support)
MB Peripheral support P Non-cement material

Claims (6)

An in-situ test method for evaluating the chemical effect of a support installed in a tunnel,
By excavating in a cylindrical shape from the inner space side to the natural ground side of the mine shaft, and filling the cylindrical gap formed by excavation with a non-cement-based material, the support and the rock mass of a predetermined depth are supported in the periphery and Isolated from the surrounding rock,
An in-situ test method characterized by measuring pore water pressure in an isolated rock mass and collecting water flowing in the isolated rock mass and monitoring the water quality .   The in-situ test method according to claim 1, wherein water is collected from a plurality of positions in the depth direction of the isolated rock. A pressure vessel with an internal space facing an isolated support is provided on the inner space side of the tunnel,
The in-situ test method according to claim 1 or 2, wherein water having the same water pressure as the pore water pressure measured at the deepest part of the isolated rock is supplied toward the support isolated from the pressure vessel. A pressure vessel with an internal space facing an isolated support is provided on the inner space side of the tunnel,
The in-situ test method according to claim 1 or 2, wherein water of a required pressure is supplied to the pressure vessel, and an assumed flow field is provided in the isolated rock mass.   After the required period has elapsed, the isolated support and the rock mass are over-cored, and a core specimen including the support and the rock mass in contact with the support is collected. The in-situ test method described in 1. By filling the gap formed in a cylindrical shape from the inner space side of the tunnel where the support is laid to the natural mountain side with a non-cement-based material, the support and the rock mass of a predetermined depth are isolated from the peripheral support and the surrounding rock mass. An in-situ test device used to evaluate the chemical effect of support in an isolated bedrock,
Measuring the pore water pressure in the isolated rock mass, and a water sampling pipe for collecting water flowing in the isolated rock mass;
An in-situ testing apparatus comprising: a pressure vessel that is inserted from the inner space side of the mine shaft to the ground side so as to surround the isolated support and the rock, and the internal space faces the isolated support.

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