JP2002156459A - Geologic survey method for existent tunnel and maintaining and managing method for existent tunnel using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To take a geologic survey of an existent tunnel while minimizing restrictions on tunnel passage. SOLUTION: The geologic survey is taken by installing impact receiving devices 12 on the passage surface A of the existent tunnel 10 and exciting them by an exciting device 16 such as a hydraulic impactor. A hydraulic small- sized exciting machine which can travel by itself is used as an excitation source and then even the existent tunnel for which explosives excitation such as blasting can not be adopted can safely and easily be surveyed. According to the geologic survey result, it is decided whether tunnel deterioration is caused by the ground state and proper maintenance measures for the deterioration place of the existent tunnel can be taken. Or geologic information is obtained which is needed to expand the width of the tunnel 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a maintenance management technique for properly performing necessary maintenance work or a construction work such as a tunnel widening work for the purpose of properly maintaining an existing tunnel and ensuring safe traffic. Regarding the prior survey technology, in particular, the geological survey of the existing tunnel will be conducted while maintaining the service condition of the existing tunnel, and necessary maintenance measures or widening work of the existing tunnel will be performed based on the results of the geological survey.

[0002]

2. Description of the Related Art Japan has many mountainous areas, and railroads and highway networks are stretched vertically and horizontally through such mountainous areas. For this reason, many tunnels are indispensable for daily traffic. In addition to mountain tunnels,
There are also submarine tunnels connecting sections separated by straits.

[0003] In such a large number of existing tunnels, a large amount of concrete is used as lining concrete covering the inner peripheral surface of the tunnel, and supports the safety of the tunnel structure. Since existing tunnels naturally deteriorate over time, necessary maintenance work such as repairing cracks on the concrete surface of lining concrete and filling up holes in the spalled concrete part is performed properly, and traffic safety is achieved. .
Prevention is achieved in advance by using a patrol or the like to visually recognize the expected spots or the like by a method such as visual inspection or hitting with a hammer.

In the problem of deterioration of the existing tunnel, the internal factor depends on the quality of the concrete itself and the construction method, and the external factor is groundwater flow, inflow, or traffic in the tunnel due to a change in ground conditions. The amount and the accompanying vibration can be considered. Among them, external factors based on the condition of the ground where the existing tunnel is located are considered to be the main cause. Degradation of lining concrete due to infiltration and softening caused by the flow of groundwater).

[0005] Therefore, when performing an appropriate maintenance operation, it is necessary to determine whether the cause is an external factor or an internal factor when judging individual situations. For example, it is necessary to determine whether the deterioration phenomena such as peeling of the lining concrete are based on the ground conditions that are in direct contact with the lining concrete or based on factors that are completely unrelated to the geological conditions such as traffic volume. It is.

[0006] For the maintenance management of the existing tunnels, diagnosis of the soundness of concrete including lining concrete, connectivity with concrete ground (whether there is no cavity between concrete and surrounding ground, etc.) ), Concrete repair technology, and research on concrete materials (chemical degradation, material properties, etc.) are required from various viewpoints, and a comprehensive measure of these approaches is desired.

As described above, the problem of tunnel deterioration in the maintenance management of the existing tunnel is related to the above-mentioned concrete material or the environmental condition of the tunnel, or to the ground conditions such as shatter zones, deterioration and stress release. It is important to clearly identify the problem and to solve it according to the problem situation when selecting an appropriate solution.

[0008] As described above, it is extremely important to properly maintain and manage the existing tunnel so that daily traffic can be performed safely. However, the existing tunnel is already suitable for the current traffic situation. Sometimes it's gone. In the current situation judgment by the maintenance management of the existing tunnel, there is a case where a tunnel having a scale suitable for a large amount of traffic is required based on the predicted increase in the traffic volume in the future, rather than performing the current state of maintenance management. In such a case, the construction of a new tunnel that is different from the existing tunnel or the widening of the existing tunnel must be considered.

However, in reality, it is more difficult to widen the existing tunnel to a large tunnel due to various factors such as the problem of architectural limitations, economy, construction conditions, and effects on the surrounding environment.
This is more advantageous than setting up a new tunnel.
Widening of existing tunnels is increasing.

[0010]

As for the maintenance and management of an existing tunnel, it is necessary to determine whether the problem at hand is related to the situation of the mountainous ground as described above. But,
For existing tunnels, the geological data on the natural conditions of the tunnel is usually not fully utilized,
It is not possible to fully understand the mountain conditions.

Regarding the condition of the ground in the tunnel, an elastic wave exploration (refraction method) and a boring survey are performed from the surface side at the time of tunnel planning, and are used as design data. In addition, the construction proceeds while confirming the actual geology of the tunnel construction site through face observation and various measurements during construction.
Therefore, the maintenance of the tunnel after completion of the tunnel should be able to identify the cause of the tunnel deterioration by using such geological survey data.

However, such materials are scattered in the existing tunnel which has been constructed for a long time after construction, so that such materials cannot be fully utilized for maintenance and management, and the cause of the tunnel deterioration cannot be practically isolated. Has occurred.

[0013] Furthermore, it is sufficiently possible that the surrounding ground after the opening of the tunnel changes over time, leading to a deteriorated geological condition different from that at the time of construction, and there is also a case where it is not possible to quickly determine the cause of the deterioration of the tunnel. is there.

As described above, in the field of maintenance management at the site,
In analyzing the cause of the deteriorated part of the tunnel, it was not possible to adequately divide the case, as described above, into the case where the concrete itself had a problem as described above, or the case where the problem occurred due to a problem in the ground conditions, and it was not possible to take proper measures In many cases, it is difficult to obtain necessary information.

[0015] Even if the results of the geological survey at the time of construction cannot be fully utilized, it is absolutely necessary to grasp the geological situation where the tunnel is located from the inside of the tunnel in order to manage the safe passage of the tunnel. As a conventional geological exploration method, a TSP method and an HSP method using blast as a vibration source have been proposed, but such methods can be applied at the time of tunnel construction. The above-mentioned method of performing geological exploration based on blasting vibration in an existing tunnel that is actually opened and where traffic is routinely performed is not a realistic exploration method.

As a method not using blasting as a vibration source, there is, for example, an elastic reflection method using high-voltage plasma as a method applied at the time of tunnel construction. In such an exploration method, it is necessary to bring a large transformer into the tunnel and generate a high voltage in the tunnel. Unlike at the time of tunnel construction, even if traffic restrictions etc. were thoroughly performed,
There is also a fear of unpredictable accidents due to stray currents due to high voltage, so it is practically unsuitable as a geological exploration method for existing tunnels.

The above-mentioned method proposed as a method for geological exploration of a tunnel is an exploration method that is necessary only when constructing a tunnel. It cannot be easily applied from various viewpoints such as safety.

In a tunnel that is used on a daily basis, especially in a tunnel with a large traffic volume, it is necessary to minimize traffic regulation even temporarily, even for geological exploration. In the case of railway tunnels and road tunnels where there is no appropriate detour other than using the tunnel, the effect of traffic regulation is extremely large, and in some cases, the economic activity in the area related to the tunnel may be significantly affected. Envisioned enough.

In such a situation, the above-described conventional method cannot be easily adopted, and when it is considered that there is a problem in the mountainous state, a method of examining the point by a boring survey or the like has conventionally been adopted. Was.

However, in a tunnel in operation, the operation is restricted, and it is actually very difficult. Also,
The data obtained by the boring survey is only data of a certain point (point), not the ground information over the entire tunnel line from the tunnel at one end to the tunnel at the other end.

Further, it is theoretically possible to conduct a boring geological survey over the entire tunnel line, but depending on the distance of the entire tunnel line, unless a very large number of boring points are set. However, it costs a lot of money and is not a realistic exploration method.

Under such site conditions, in recent years, lining concrete has come off, which has become a major social problem. By non-contact, non-destructive investigation method, the ground condition of the entire tunnel of the existing tunnel actually used is safely and easily explored without significantly affecting the usage situation, and the results It is urgently necessary to formulate an appropriate tunnel degradation measure based on this.

On the other hand, in parallel with the problem of maintenance and management of the existing tunnel, the widening work is carried out in view of the maintenance and management costs required for maintaining the current state in view of the current situation of the existing tunnel and an increase in future traffic volume. In some cases, renewal measures for existing tunnels, including the above, may be necessary.

Considering the recent traffic situation, the traffic of large vehicles is increasing more than before, and the existing tunnel is to be replaced with a large one in consideration of the problem of building limits, economy, construction conditions and surrounding environment. Work to widen the tunnel is increasing. When a new tunnel is set up separately from an existing tunnel, various problems are involved, including land acquisition.
It is difficult to respond early. Unlike the case of such a new tunnel, the widening of the existing tunnel makes it easier to respond quickly. In such widening work, geological information on the widening side of the existing tunnel is required.

In tunnel construction, geological surveys are conducted at the planning and design stages, and at the time of construction, excavation is carried out while examining the tunnel geology through face observation and various measurements. In many cases, geological information necessary for construction cannot be obtained. In particular, there are many cases where various materials are not provided at all in a tunnel whose construction time is old (for example, a tunnel that has passed 30 years or more after construction).

Also, even if there are existing survey results,
In many cases, it does not conform to the current technical level (investigation method, tunnel excavation method). In this case, it is desirable to conduct another survey that conforms to the current technical level. As described above, in the widening work of the existing tunnel, a new survey on the geological information such as the surrounding mountainous condition is required as in the case of the maintenance management measures.

With regard to the geological survey of the existing tunnel, the same problem as that involved in the geological survey performed when separating the influence of the ground condition for the maintenance management occurs. In other words, it is conceivable to carry out surveys under livelines while minimizing traffic restrictions, and to investigate boring geology.

Therefore, even as a geological exploration method for widening the existing tunnel, the geological condition of the entire tunnel of the existing tunnel can be changed without greatly affecting the use state.
A safe and simple exploration technique is preferred. It is preferable that a method of exploring the state of the ground at the widened portion of the tunnel be applied by a non-contact / non-destructive investigation method.

Further, if geological information is obtained by such a method, an appropriate boring point can be confirmed even if a situation in which a boring survey is used for a more detailed survey occurs.

The object of the present invention is to provide an existing tunnel
The aim is to conduct geological exploration while minimizing tunnel traffic restrictions.

Another object of the present invention is to easily perform a geological survey without hindering the passage of a tunnel even in an existing tunnel in which geological materials cannot be used, and based on the result,
The purpose is to enable sufficient maintenance and management of the tunnel.

Another object of the present invention is to easily perform a geological survey without hindering the passage of a tunnel even in an existing tunnel where geological materials cannot be used, and based on the result,
The purpose is to be able to use it for preliminary surveys such as tunnel widening work.

[0033]

The geological exploration method for an existing tunnel according to the present invention is a method for exploring the geology around an existing tunnel after opening, and includes a method for detecting the geology of one of the existing tunnels from one tunnel entrance to the other tunnel entrance. A plurality of vibration receiving devices are installed at a predetermined interval, and the inside of the existing tunnel pit is hit with a vibration generating device to generate vibration in response to the vibration receiving device. A reflected wave according to a mountain condition is received by the vibration receiving device, and the reflected wave is analyzed to search for geology around the existing tunnel.

A section from the one tunnel entrance to the other tunnel entrance is divided into a plurality of geological measurement sections, and the plurality of vibration receiving devices are installed by moving the plurality of geological measurement sections in order. It is installed over the entire line of the existing tunnel. The vibration receiving device is installed on an underground traffic surface of the existing tunnel and / or on a lining concrete surface, and the vibration device hits and excites the underground traffic surface of the existing tunnel.

In the analysis, at least a forward reflected wave reflected from a position ahead of the front end of the front and rear ends of the measurement section and a back reflected wave reflected from a position behind the rear end are used. And The front reflection is a front reflection wave reflected from a measurement section immediately before a front end of the measurement section, and the rear reflection is a rear reflection wave reflected from a measurement section immediately after a rear end of the measurement section. The ground condition of each measurement section is analyzed by superimposing the forward reflected wave obtained by the measurement in the immediately following measurement section and the back reflected wave obtained by the measurement in the immediately preceding measurement section. Features. The polymerization may be performed, for example, such that the waveforms of the front reflected wave and the rear reflected wave are overlapped on the same drawing.

The geological information obtained by the geological exploration method for an existing tunnel having any one of the above-mentioned structures is used for a pre-construction pre-construction survey of the existing tunnel, such as widening work. Geological exploration method.

The present invention is a maintenance management method for an existing tunnel in which a judgment is made as to whether or not the cause of the deterioration of the tunnel in the existing tunnel is based on the condition of the ground, and based on the judgment, maintenance measures are taken for the deteriorated portion of the tunnel. The determination as to whether or not the cause of the tunnel deterioration is based on the ground condition is performed based on geological information obtained by applying the geological exploration method of the existing tunnel.

In the above configuration of the present invention, for example, a plurality of geophones are installed on the traffic surface of the existing tunnel, and vibration is generated by a vibration device such as a hydraulic impactor corresponding to the location of the vibration device on the traffic surface. Thus, safe geological exploration can be performed without using blasting as a vibration source. A self-propelled hydraulic small vibration exciter can be used as the vibration source, so it is possible to easily conduct geological surveys of existing tunnels that are actually used without any significant traffic restrictions such as blocking all roads. be able to.

By using a vibration generating device such as a hydraulic impactor or a hydraulic vibrator as a vibration generating source, a vibration generating device having a frequency characteristic in accordance with the ground characteristics can be adopted, and a more accurate vibration of an existing tunnel can be adopted. High ground conditions can be grasped.

[0040]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIGS. 1A and 1B are explanatory diagrams showing the installation status of measuring instruments in a pit when performing geological exploration necessary for maintenance management of an existing tunnel. FIG.
FIG. 2 is a plan view schematically showing the situation of FIG. 1 as viewed from above in the tunnel.

As the existing tunnel 10 shown in FIG.
For example, it is assumed that a long time has passed since the construction, the result of the geological survey at the time of the construction is not easily available, and a geological survey for smooth maintenance and management of the tunnel 10 is required again. It is assumed that the tunnel 10 is regularly used as a road tunnel, and it is difficult to completely block traffic for geological exploration.

According to the geological exploration method of the existing tunnel of the present invention, the geological exploration can be performed only in the other one lane while securing one side of the tunnel 10, that is, while allowing the vehicle to pass on one side. .

As shown in FIGS. 1 and 2, in a section from one well 11a to the other well 11b of the tunnel 10, a plurality of measurement sections of the same length are formed on the entire tunnel along the direction in which the tunnel 10 is laid. The line section L is set. 1 and 2, only one measurement line section L is shown for simplicity.

As shown in FIG. 2, since the measurement line section L is set to one lane in the tunnel as described above, it is not necessary to restrict the entire traffic in the tunnel when applying the present invention. Only one-sided traffic regulation is required. This is shown in FIG. In FIG. 3A, the left side of the drawing is secured so that a vehicle W or the like can pass, and the geological exploration is performed by setting the survey line section L on the right side of the drawing.

In the survey line section L, as shown in FIG. 1, a plurality of vibration receiving devices 12 are provided along the tunnel direction. The vibration receiving devices 12 are installed at predetermined intervals on the traffic plane A along the tunnel direction in the survey line section L. In the case shown in FIG. 1, a configuration in which eight vibration receiving devices 12 are arranged is shown for simplicity. However, an appropriate pitch is set so that accurate measurement data can be obtained, and the pitch is matched. An appropriate number of vibration receiving devices 12 may be installed according to the site conditions of the survey line section L.

A plurality of vibration receiving devices 12 are connected in groups of several units, and each group is connected to a remote unit 13 which is an A / D converter. The remote units 13 are connected as shown in FIG. 1 and further connected to a recording / analysis device 14.

As the vibration receiving device 12, for example, a geophone (small seismometer) 12a having a configuration shown in FIG. 4 may be used. The geophone 12a is composed of a vibration receiving device main body 15a and a spike portion 15b detachably provided on the vibration receiving device main body 15a. Basically, the spike portion 15b is inserted into the measurement ground surface to form the geophone 12a. It is configured so that it can be fixed.

Therefore, when the traffic surface A is unpaved,
As shown in FIG. 4 (A), the spike portion 15b may be inserted and fixed to the traffic surface as it is, but if paving such as asphalt pavement is applied, mounting that can be stably mounted on the traffic surface A The vibration receiving device body 15 having the seat once provided on the passage surface A and the spike portion 15b removed from the mounting seat.
What is necessary is just to fix and install a.

The plurality of vibration receiving devices 12 installed in this manner
Are digitized by the remote unit 13 and then sent to the recording / analyzing device 14 for recording,
Is parsed. As shown in FIG. 1B, the recording / analyzing device 14 is configured to issue a wired or wireless oscillation command to a vibration generating device 16 that vibrates near the vibration receiving device 12.

As the vibration generator 16, for example, a hydraulic impactor shown in FIG. 5 may be used. A small vibrating device that generates an elastic wave can be used by hitting and hitting the ground plane that is moved up and down hydraulically with the traffic plane A. Alternatively, apply the vehicle weight to the diaphragm
Alternatively, a vibrator such as a hydraulic vibrator, which can change the frequency of the generated elastic wave by being press-bonded, may be used.

As shown in FIGS. 1 to 3, the vibration generating device 16 sequentially moves near the sides of the plurality of vibration receiving devices 12 and strikes the roadbed surface A to generate vibration and generate elastic waves. The frequency of the generated elastic wave may be changed in accordance with the conditions of the ground at the site. The frequency may be changed by selecting and using the vibration generating device 16 that generates an elastic wave suitable for the frequency.

The vibrating is performed for each of the plurality of vibrating devices 12 in the above-described manner. If necessary, the vibrating (called stacking or superimposing) is performed a plurality of times at the same vibrating place.

The elastic waves generated by vibrating the vibrating device 16 in the vicinity of the respective vibration receiving devices 12 propagate radially in the ground from the point of vibration and change the geology in the ground. Is reflected by Such a reflected wave is received by the vibration receiving device 12, and the reflected wave is analyzed from the relationship between the elastic wave velocity and the reflection time, so that the location of the geological boundary surface can be known.

The reflected wave received by the vibration receiving device 12 may be a reflected wave directly below the excitation point (hereinafter referred to as a reflected wave directly below), or a reflected wave from underground located in front of the excitation point. (Hereinafter, referred to as a forward reflected wave) and a reflected wave from the underground at a position behind the excitation point (hereinafter, referred to as a backward reflected wave).

Therefore, the geological survey of the survey line section may be performed based on the analysis result of the directly reflected wave and the analysis results of the forward reflected wave and the backward reflected wave. As shown in FIG.
Exploration of the horizontal structure of the geology immediately below the survey line section by using the reflected wave immediately below which the elastic wave generated from the excitation point of , Called horizontal structure exploration).

Further, as shown in FIG.
The acoustic wave generated from the point of excitement is reflected by the geological boundary surface running in the direction crossing the roadbed surface A ahead of the point of excursion. Exploration of the vertical structure of the geology in the survey section in front of Similarly, the back reflection wave can also be used to search for a vertical structure in the rear measurement section (hereinafter, referred to as a vertical structure search).

That is, as shown in FIG. 6 (C), the horizontal structural condition of the geology using the direct reflection and the geological structure using the forward reflected wave and the backward reflected wave are generated by the excitation in the survey line section. Investigate the vertical structural status of each, and understand the overall geological status.

When analyzing the forward reflection wave and the back reflection, as shown in FIG. 7, the immediately preceding measurement line section L1 set adjacent to the front of the measurement line section L and the setting of the immediately preceding measurement line section L adjacent to the rear of the measurement line section L are used. Immediately after this, the geological situation with the survey line section L2 can be known. In the analysis of the reflection data shown in FIG. 7, the case where the reflection data immediately below the measurement line is omitted and the front reflected wave and the rear reflected wave are analyzed is shown. The analysis of the superposition of the forward reflected wave and the rear reflected wave and the analysis of the directly reflected wave may be performed separately.

When analyzing the reflection data, the reflected waves within a predetermined range of reflection time are used, so that the obtained reflection data can be narrowed down to only the reflection data from the set immediately before or after the set line section. it can.

In FIG. 7, the line section L, the immediately preceding line section L1, and the immediately following line section L2 are set on the horizontal axis assuming the entire tunnel line. On the lower side of the horizontal axis taking the survey line section L, the front reflected wave reflected by the area corresponding to the immediately preceding survey line section L1 of the elastic wave generated by the vibration generator 16 in the survey line section L, the rearward reflected wave in the area corresponding to the immediately following survey line section L2, and the rear side An analysis diagram F of the reflected wave is shown. In the analysis diagram F, the reflection time may be taken in the vertical axis direction, and the installation point of the vibration receiving device arranged in the measurement line section L, that is, a plurality of vibration receiving points s may be taken in the horizontal axis direction. Data on the number of reflected waves corresponding to the number of receiving points s is acquired.

The reflection time is short when the light is reflected from a short distance and long when the light is reflected from a long distance. Therefore, if the reflection time is set in an appropriate range as described above, it is set in advance. Immediately preceding reflection section L having the specified section length
1. It is possible to narrow down the reflected wave for analysis to only the reflected wave corresponding to the immediately following reflection section L2 and perform the analysis. In FIG. 7, the state of the reflected wave is omitted from the central part in the analysis diagram for simplicity.

From the analysis of the forward reflected wave and the backward reflected wave, the boundary between the few geological features of the reflecting surface and the multiple geological features of the reflecting surface can be found.
The existence of the boundary surface where the geology changed from soft to hard and from hard to soft, and the geological condition of how long the soft zone and the hard zone corresponding to these boundary surfaces respectively continue.

Incidentally, in order to obtain data with good accuracy, the intervals of the vibration receivers 12 may be shortened, but a larger number of the vibration receivers 12 will be installed. In the experiment, it was confirmed that accurate data acquisition was possible if the sensors were installed linearly at 1.5 to 2 m intervals. Of course, the installation interval may be appropriately set in consideration of the site situation and the accuracy of the desired data.

The analysis diagram F of the survey line section L in FIG. 7 schematically shows an analysis waveform group in which reflected waves other than the front reflected wave and the back reflected wave are removed as noise. The large number of reflected waves shown in the analysis waveform group indicate the front reflection wave and the rear reflection wave received at the reception point s corresponding to the many excitation points shown on the horizontal scale of the analysis waveform group on a one-to-one basis.

FIG. 7 shows that each of the forward reflected wave and the backward reflected wave is caused to vibrate a plurality of times at each of the vibration points, and the waveform superimposed by the individual stacking is applied to another vibration different from the vibration point. A plurality of reflected waves obtained by oscillating at a point are subjected to position correction as performed at the oscillating point, and a superimposed waveform is further superimposed.

The reason why the two different stacking operations can be easily performed is that the present invention uses a self-propelled vibration generating device without using blasting as a vibration generating source.

As shown in FIG. 7, the group of analyzed waveforms is
It can be seen that there are portions where large waves x are continuously seen and portions where small waves y are seen continuously. Each receiving point s
At the boundary between the large wave x and the small wave y at a straight line, diagonally above and to the right (or diagonally above and to the left of the drawing)
By extending the extrapolation line z toward, it is possible to predict the existence of an interface between a relatively hard geology and a relatively soft geology where a large wave is reflected forward (or backward reflected wave). It can be determined that the portion where many large waves x are seen is relatively hard geology, and the portion where many small waves y are seen is relatively soft geology.

That is, it is possible to read the intersection distance between the extrapolated line z connecting the crests at the boundary between the portion where many large waves x can be seen and the portion where many small waves y can be seen and the horizontal axis. For example, it can be roughly determined that there is a boundary surface (geological boundary surface) between the soft and hard parts of the geology from the survey line section L1. FIG. 7 shows a case where the geological situation before and after the survey line section L is zoned by the front reflection surface or the number of back reflection waves.

The immediately preceding survey line section L thus determined
1. The geological condition of the immediately following survey line section L2 is shown on the horizontal axis of the corresponding section. In FIG. 7, in the immediately preceding survey line section L1, from the side closer to the survey line section L, in order, toward the front (in FIG. 7, toward the right side of the drawing), the reflecting surface with few reflecting surfaces, the geology (hard), and the reflecting surface A complex geological situation where the geological situation frequently changes is confirmed as many reflecting surface multi-geological (soft), reflecting surface low geological (hard), reflecting surface multi-geological (soft), reflecting surface low geological (hard).

On the other hand, immediately after the line section L2, the line section L
From the side close to, sequentially toward the rear (in FIG. 7, toward the left side of the drawing), the reflection surface with low geology (hard), the reflection surface with multiple geology (soft), and the reflection surface with low geology (hard) repeat at substantially equal intervals. It is clear that the geological conditions are relatively stable. In this way, from the survey in the survey line section L, the geological conditions of the immediately preceding and following survey line section L1 and the immediately succeeding survey line section L2 can be known.

When the geological survey in the survey line section L is completed in this way, the geological survey is performed by moving to the immediately preceding survey line section L2. In this embodiment, since the plurality of survey line sections are set to the same length, the survey line section L and the immediately preceding survey line section L1 have the same length, and the same as when the vibration receiving device 12 is set in the survey line section L. Thus, the installation of the vibration receiving device 12 can be easily performed. The vibration receiving device 12, the remote unit 13, the recording / analysis device 14, and the like are set in the same way as the survey line section L, and the vicinity of the arranged plural vibration receiving devices 12 is sequentially vibrated by the vibration generating device. A geological survey of the survey line section L1 may be performed.

In the geological survey of the survey line section L1, the forward reflected wave and the backward reflected wave are analyzed in the same manner as in the survey line section L, and the immediately preceding survey line section L3 and the immediately preceding backward survey line are compared with the immediately preceding survey line section L1. A geological survey of the survey line section L corresponding to the section is performed. In this manner, the vibration receiving device 12 is installed by sequentially moving the plurality of measurement line sections, and the vibration
, The data is acquired while receiving the reflected wave, and finally the data over the entire tunnel can be acquired.

As described above, while sequentially moving along the survey line section, the geological data of the section immediately below, immediately before, and immediately after the survey line section are acquired, and the geological state of the entire tunnel line is analyzed by combining these geological data. The procedure is shown in FIG. FIG.
, Along the entire tunnel, set six blocks of measurement line sections a, b, c, d, e, and f, and sequentially move through each measurement line section, using reflected waves before and after. Shows how to conduct a geological survey.

FIG. 8 shows a state in which the geological condition obtained in each of the measurement line sections is grasped from data of measurement line sections before and after the measurement line section currently being measured. In the survey line section adjacent to the pits at both ends of the tunnel, the reflection of either the forward reflected wave or the backward reflected wave is obtained as data.

That is, in the measurement in the survey line section a of FIG. 8, the geological result of the survey line section b corresponding to the immediately preceding survey line section and the geological result of the section outside the tunnel entrance are obtained as the forward search result A1. . In the measurement in the survey line section b, the geological result of the survey line section c corresponding to the immediately preceding survey line section and the rear search result B
As 2, the geological result of the line section a corresponding to the immediately following line section is obtained.

In the measurement in the line section c, the geological result of the line section d corresponding to the immediately preceding line section is obtained as the forward search result C1, and the geological result of the line section b corresponding to the immediately following line section is obtained as the backward search result C2. In the measurement in the survey line section d, the geological result of the survey line section e corresponding to the immediately preceding survey line section is obtained as the forward search result D1, and the geological result of the survey line section d corresponding to the immediately following survey line section is obtained as the backward search result D2.

In the measurement in the line section e, the geological result of the line section f corresponding to the immediately preceding line section is obtained as the forward search result E1, and the geological result of the line section e corresponding to the immediately following line section is obtained as the backward search result E2. In the measurement in the survey line section f, the geological result of the survey section e corresponding to the immediately following survey section is obtained as a forward search result of the area outside the tunnel entrance and a rearward search result F2.

As described above, except for the survey line sections on both sides of the tunnel at both ends of the tunnel (for example, corresponding to a and f in FIG. 8), the geological result of each survey line section is as shown in the analysis result at the bottom of FIG. , A1 + C2, B1 + D2, C1 + E2, D1 + F
As in 2, for example, the analysis can be performed as a superposition of the forward search result and the backward search result. In the present invention, since the measurement data of both the front and the rear of each survey line section can be matched, compared with the case of analyzing based on either one of the data, the accuracy is higher and a detailed geological survey can be performed. .

Further, in each survey line section, in addition to the result of the vertical structure exploration obtained from the front and rear reflected waves, the horizontal structure exploration result can be obtained from the immediately below reflected wave as described above. Geological exploration results with higher accuracy than the analysis results of

As shown in FIG. 9, by performing the analysis in the above-described manner, for example, a crush zone,
Alternatively, it is confirmed that there is a fragile portion of the ground, a geological boundary, and the like, and that the ground is loose, for example, can be confirmed behind.

According to the geological exploration method for an existing tunnel of the present invention, as described above, without restricting traffic on the entire surface,
Since the geological exploration of the tunnel can be performed with a simple exciter, the tunnel maintenance management method of the present invention incorporating such an exploration method does not greatly impede traffic even in a high-traffic trunk tunnel, etc. In addition, appropriate maintenance measures against tunnel degradation can be formulated.

In the above description, a plurality of survey line sections (measurement sections) are set in advance, and reflected wave data is acquired in each survey line section by moving a set of a vibration receiving device or the like sequentially through each survey line section. Although the method of performing the analysis has been described, for example, in the case of a short tunnel, a vibration receiving device may be installed at a predetermined interval over the entire tunnel and measurement may be performed. In the analysis stage, a method of analyzing data by dividing the data into a plurality of survey line sections may be adopted. Of course, the analysis can be performed without dividing the data into a plurality of measurement line sections.

In a long tunnel or the like, an extremely large number of vibration receiving devices must be installed to install the vibration receiving devices on the entire line at one time. As described above, if a plurality of measurement line sections are set in advance and a certain limited number of vibration receiving devices are sequentially moved and measured, it is easy to deal with the site.

In such a case, for example, a plurality of sets of vibration receiving devices and the like to be installed in the measurement line section are prepared, and while the measurement is currently being performed by the vibration generator, a forward movement is performed to the measurement line section ahead. If you set the vibration receiving device, etc., the vibration is not stopped every time the vibration receiving device is set, and the vibration is continuously generated toward the survey line section where the vibration receiving device is set ahead. Therefore, efficient geological exploration work can be performed.

Next, the maintenance management method for the existing tunnel according to the present invention will be described. The tunnel maintenance management method of the present invention is a method for appropriately performing maintenance and management measures based on the results based on the above-described geological exploration method for an existing tunnel.

A monitoring patrol over the entire line of the tunnel examines the state of deterioration of the tunnel in detail. For example, how much cracks are in the lining concrete in the pit, how much concrete is not peeling, etc.
Observe the situation closely and record the situation. At the time of recording, the situation is sketched or photographed as appropriate.

At the same time, the ground conditions around the existing tunnel are determined in accordance with the geological survey method described above. Along the whole line of the tunnel, we break down each small section and examine the mountain conditions in detail. Such a small section may be the same as the survey line section defined by the geological survey. By applying the geological exploration described above, the geological configuration, the ground strength, the deterioration range, the ground bearing capacity, and the like for each survey line section are evaluated.

The evaluation and the deterioration state of the tunnel obtained by the monitoring patrol and the like are compared for each survey line section, and summarized in a document form such as a tunnel deterioration investigation report or data readable and writable by a computer. deep. At the time of summarizing, along the entire line direction of the tunnel, for each measurement line section, for example, in m units or cm
It is necessary to make it possible to quickly compare the geological situation and the degradation situation at that position in units.

Further, the tunnel deterioration report includes:
It is possible to easily describe the state of change of the deterioration state and the mountainous state in the future, and to make it possible to quickly compare aging.
According to the confirmation of the tunnel deterioration report, the geology corresponding to the tunnel deterioration site is, for example, tuff or mudstone,
Or, if necessary, make sure that it is oresite.

In this way, for example, it is possible to quickly determine whether the deterioration of a tunnel such as a crack in lining concrete is based on an external factor such as a geological condition or other internal factors. I can do it. If it is determined that an external factor based on the surrounding mountainous condition is the cause of the crack, the crack is further compared with the age based on the above-mentioned tunnel deterioration investigation report. to decide.

When the progress of the cracks is not substantially recognized, and it can be judged from the geological survey results that the surrounding ground is stable, for example, an adhesive is injected into the cracks of the lining concrete to enlarge the cracks. It is determined that so-called repair measures such as prevention of peeling should be taken.

On the other hand, crack progress was observed, and
If it is recognized that the load capacity of the tunnel structure has been relatively reduced due to the influence of the surrounding ground being unstable, the tunnel capacity should be reduced to prevent the load capacity of the tunnel structure from decreasing or to improve the load capacity. Judge that structural reinforcement should be provided.

As described above, in the maintenance management method for the existing tunnel of the present invention utilizing the above-described geological survey method for the existing tunnel, the present invention is based on the geological survey result obtained by the geological survey method described above. Judgment is made as to whether the cause of tunnel deterioration is due to the surrounding mountainous conditions, and if it is determined to be due to the mountainous conditions, the tunnel deterioration state is compared with the mountainous conditions, and repair measures are taken. It is possible to quickly and accurately determine whether the completion is completed or whether reinforcement measures for the tunnel structure are required.

For this reason, a forward reflected wave and a backward reflected wave can be obtained by a vibrating method of hitting a roadbed surface with a simple movable exciter without a large traffic restriction and without using a blasting exciter. In comparison with the conventional tunnel maintenance and management method according to the present invention, which can not be combined with an appropriate geological survey method of the surrounding mountainous condition of the present invention that can perform detailed geological survey using the above, the maintenance management of the existing tunnel according to the present invention The method is a maintenance management method that can accurately determine whether the cause of the tunnel deterioration is due to the surrounding mountainous conditions, and is extremely effective for tunnel safety management.

As described above, by using the geological exploration method of the present invention, it is possible to obtain geological information such as the state of the mountain surrounding the tunnel necessary for the maintenance and management of the existing tunnel. Can also be applied to geological surveys required for widening construction of existing tunnels. Hereinafter, such an application method will be described.

For example, as shown in FIG. 10, a case will be described below in which the existing tunnel 10 indicated by the broken line in the figure is to be widened rightward in the drawing in anticipation of an increase in traffic volume in the future. .

As shown in FIG. 1, on the right side, a geophone 12a is used as the vibration receiving device 12 at predetermined intervals along the tunnel direction of the tunnel 10 so as to be able to alternately pass on the left side as viewed in the drawing of the tunnel 10. To form a survey line. The vibration receiving device 12 is installed near the wall surface side of the tunnel 10, and is vibrated by the vibration generating device 16 on the side of each vibration receiving device 12, and the reflected wave and the refracted wave of the generated elastic wave are received by the vibration receiving device. 12 is received.

By applying the elastic wave refraction method together with the elastic wave reflection method to the data obtained in this way, and analyzing the critical refraction wave on the data, it is different from that obtained by the elastic wave reflection method. Geological information can be obtained.

The elastic waves radiated from the point of excitation are direct waves,
The reflected wave reaches the receiving point as a refracted wave, but if the elastic wave velocity of the layer below the surface layer is faster, the refracted wave is observed as the earliest arriving wave (initial) at the receiving point that is more than a certain distance away. You. Therefore, at each vibration receiving point, a travel time curve which plots the travel time as the initial arrival time at a distance from the excitation point is created to grasp the geological condition.

In the analysis by the elastic wave reflection method, FIG.
As shown in (A), the time at which the reflected wave returns and the reflection position (reflection depth, reflection location) can be known. Therefore, compared to the elastic wave refraction method, as shown in FIG. 7, the position of the boundary surface where the elastic wave velocity at a deep depth changes from fast to slow or from slow to fast can be found. From the change in the reflection intensity, a specific reflected wave analysis geological structure corresponding to the change can be known.

On the other hand, in the analysis by the elastic wave refraction method, FIG.
As shown in FIG. 1 (B), the time at which a refracted wave of a certain elastic wave velocity (Vp) returns is known. From the time, the distance between the vibration receiving point and the vibration excitation point is known, the velocity structure between the vibration receiving point and the vibration excitation point is known, and the specific geological structure is known from the velocity structure. In the analysis by the elastic wave refraction method, it is possible to know the geological structure of the refraction wave analysis that is captured as a zone of the elastic wave velocity at a shallower depth than the elastic wave reflection method.

By using both the elastic wave analysis geological structure and the refraction wave analysis geological structure obtained by analyzing each of the reflected wave and the refracted wave in this way, the continuity from the shallow depth to the deep depth of the ground surface can be obtained. Geological information on the geological structure can be obtained. The analysis of the horizontal structure may be performed by analyzing the refraction wave from just below the underground of the survey line, and the analysis of the vertical structure may be performed by analyzing the refraction wave from the underground before or after the survey line.

When technically analyzing the cause of deterioration from the viewpoint of maintenance and management of the existing tunnel, it is considered that geological information obtained by the elastic wave reflection method is sufficient. However, widening of the existing tunnel which actually requires excavation work is considered. Then, the refraction wave analysis geological structure based on the elastic wave refraction method becomes useful geological information in addition to the reflected wave analysis geological structure.

In the drawing, the search area 17 in the widening direction of the tunnel 10 is indicated by a dotted line. As shown in FIG. 10, a new widening tunnel 1 based on the two geological structures and the geological information related to the respective analysis of the reflected wave and the refracted wave in the exploration area 17
8 may be formed.

In the case shown in FIG. 12, the existing tunnel 1
This shows the geological exploration situation when 0 is widened in the left-right direction. In this case, for example, the geological exploration on the right side may be performed with the alternate traffic on the left secured, and then the geological exploration on the left with the alternate traffic secured on the right. In this manner, the geological information in the horizontal and vertical directions on the left and right, which is the direction in which the tunnel 10 widens, can be obtained as described above.

The present invention is not limited to the above embodiment, and may be changed as needed without departing from the gist of the present invention.

For example, in the above description, the case where the method of generating the traffic surface by the vibration device is employed has been described. However, the side wall surface of the tunnel or, if possible, the ceiling surface may be generated. Regarding the shape of the tunnel pit,
Although the above description has been made assuming a vaulted tunnel, for example, as shown in FIG. 3 (B), the present invention can be applied without any problem even when the pit has a rectangular shape.

For example, in the above description, a case is shown in which one lane on one side is completely stopped and one-sided traffic is performed. However, in a long tunnel, it is configured to be able to pass both before and after the line section and avoid only the line section. If the traffic is restricted, the geological exploration can be performed with the traffic restricted.

In the above description, the case of a road tunnel has been described, but the same can be applied to a railway tunnel. In this case, the exciter may be configured to be able to run on railroad rails. Alternatively, it is also possible to advance by vibrating the shoulder side of the rail.

Also, a tunnel is designed in advance so that a space for installing the vibration receiving device and a space for a vibration generating point by the vibration generating device are provided in the tunnel so that geological exploration can be performed as needed even after opening. It is also preferred.

In the analysis, if it is determined that the information on the horizontal structure immediately below the tunnel is not important, depending on the situation of the ground around the tunnel, the reflected waves immediately before and after the tunnel are not analyzed. May be analyzed.

The application of the present invention does not need to be limited to a mountain tunnel at all, but can also be applied to a submarine tunnel. In particular,
The application of the present invention is effective in a submarine tunnel, since a large water pressure is always applied, and it is not possible to neglect confirmation of the state of flooding in the tunnel and to use blasting vibration. The application is not limited to tunnels, and can also be applied to geological exploration of underpasses, caves, caves, and the like having substantially the same configuration as tunnels.

[0113]

According to the present invention, the geological exploration of an existing tunnel can be performed by using a vibration generating device for generating vibration by hitting a traffic surface or the like in a tunnel pit. In particular, since blasting vibration is not adopted, it is possible to search safely without damaging existing tunnels.

According to the present invention, unlike the case of the blasting vibration, the frequency of the generated elastic wave can be changed according to the ground conditions, and the geological exploration with higher accuracy can be performed by using the vibration generating device. It is. Further, unlike the case of blasting and vibration, there is no limitation on the position of the vibration, so that the vibration can be freely selected not only on the traffic surface of the existing tunnel but also on the inner surface of the tunnel pit or the ceiling surface.

The installation position of the vibration receiving device may be any position in the tunnel pit, such as on the traffic surface of the tunnel or near the side wall, and the degree of freedom in installing the device is higher than that of the blasting vibration. There is no need for drilling work at both the excitation position and the vibration receiving position,
There is no hassle in setting up before measurement.

According to the present invention, a plurality of measurement sections are provided along the entire tunnel line, and a plurality of excitation and receiving points are provided. Since the reflected wave ahead of the point and the reflected wave behind it can be superimposed and analyzed, more accurate geological exploration can be performed.

Unlike blasting and vibration, individual stacking can be performed in which vibration is performed a plurality of times at the same point, so that geological exploration can be performed with high accuracy even if the elastic wave energy is smaller than that in the case of blasting and vibration.

By using the vibration generating device, the energy of the elastic wave generated can be reduced as compared with the blast vibration, and the rate of transmission of the elastic wave is small even at a position relatively close to the vibration position. In the blasting vibration, data in a relatively close neighborhood section from the measurement section in which the detailed search cannot be performed to about 100 m can be determined in detail.

The data at different measurement positions can be superimposed and evaluated in the same tunnel, and the measurement accuracy improves as the number of times of measurement increases. The first measurement data can be reflected in the second, third, and subsequent measurements.

The geological exploration method of the existing tunnel of the present invention is as follows.
It can be used as preliminary survey data for geological survey of widening construction of existing tunnels, and geological survey in widening construction can be performed under live lines.

In the maintenance management method for the existing tunnel according to the present invention, since the geological survey result based on the geological survey method for the existing tunnel according to the present invention is used, it is possible to take an accurate maintenance measure different from the conventional one. In addition, since the geological exploration method of the existing tunnel of the present invention is a method that does not use blast vibration and the like, geological exploration can be performed without incurring a large cost, and even a large number of small tunnels can be inexpensive. Maintenance management.

[Brief description of the drawings]

FIG. 1A is an explanatory diagram showing an example of an arrangement state of measuring instruments in a tunnel to which the present invention is applied, and FIG.
FIG. 4 is an explanatory diagram showing a connection state of a recording / analysis device.

FIG. 2 is a plan view showing a state of excitation and reception in a tunnel pit.

FIGS. 3A and 3B are cross-sectional views showing a state in which geological exploration is performed while one-way traffic is performed in a tunnel mine.

FIG. 4A is a cross-sectional view showing the installation state of the vibration receiving device, and FIG. 4B is a perspective view showing the state of the installed vibration receiving device.

FIG. 5 is a side view showing a situation where a vibration is generated using a vibration generating device.

6A is an explanatory diagram showing a state of a horizontal structure exploration by a reflected wave immediately below, FIG. 6B is an explanatory diagram showing a state of a vertical structure exploration by a front and rear reflected wave, and FIG. It is explanatory drawing which shows both the horizontal structure exploration and the vertical structure exploration in the area.

FIG. 7 is an explanatory diagram showing a use state of an analysis diagram using a forward reflected wave and a backward reflected wave.

FIG. 8 is an explanatory diagram showing a procedure for performing a geological survey by dividing the entire tunnel into a plurality of measurement sections.

FIG. 9 is an explanatory diagram illustrating an example of a geological situation determined from an analysis result.

FIG. 10 is an explanatory diagram showing a case where a geological survey is performed to widen a tunnel in one direction.

11A is a schematic diagram illustrating a state of reflection of an elastic wave, and FIG. 11B is a schematic diagram illustrating a state of refraction of an elastic wave.

FIG. 12 is an explanatory diagram showing a case where a geological survey is performed to widen a tunnel on both sides.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Tunnel 11a Wellhead 11b Wellhead 12 Vibration receiving device 12a Geophone 13 Remote unit 14 Recording / analysis device 15a Vibration receiving device main body 15b Spike section 16 Exciter 17 Exploration area 18 Widening tunnel a Line section b Line section c Line section d Line section d Line section Section A Traffic surface A1 Forward search result A2 Backward search result B1 Forward search result B2 Backward search result C1 Forward search result C2 Backward search result D1 Forward search result D2 Backward search result E1 Forward search result E2 Backward search result F1 Forward search result F2 Exploration results L Line section L1 Line section immediately before L2 Line section immediately after L2 Line section W3 Vehicle

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takuo Kato 4-25-2 Sendagaya, Shibuya-ku, Tokyo Inside Fujita Co., Ltd. (72) Inventor Takeshi Igawa 1-2-5-1 Otsuka, Bunkyo-ku, Tokyo Stock Association (72) Inventor Nobuyuki Shimizu 1-5-21 Otsuka, Bunkyo-ku, Tokyo, Japan Inventor Shigeru Suda Inventor Shigeyuki Suda 1-5-21, Otsuka, Bunkyo-ku, Tokyo, Japan 2D055 LA16 LA17 F-term in the Earth Sciences Research Institute, Inc. (reference)

Claims (7)

[Claims] 1. A method for exploring the geology around an existing tunnel after opening, comprising: installing a plurality of vibration receiving devices at a predetermined interval from one tunnel entrance of the existing tunnel to the other tunnel entrance; In response to the above, the existing tunnel mine is hit with an exciter to excite it, and a reflected wave of the elastic wave generated by the excitement according to the surrounding ground condition in contact with the existing tunnel is received by the exciter, A geological exploration method for an existing tunnel, characterized by analyzing the reflected wave and exploring a geology around the existing tunnel. 2. The geological exploration method for an existing tunnel according to claim 1, wherein a region from the one tunnel entrance to the other tunnel entrance is divided into a plurality of geological measurement sections, and the plurality of vibration receiving devices are arranged in a plurality. The geological survey method for an existing tunnel is characterized in that the geological measurement section is sequentially moved to be installed over the entire line of the existing tunnel. 3. The geological survey method for an existing tunnel according to claim 2, wherein the vibration receiving device is installed on an underground traffic surface and / or a lining concrete surface of the existing tunnel, and the vibration device is mounted on the existing tunnel. A geological exploration method for an existing tunnel, characterized in that the underground traffic surface is hit and vibrated. 4. The geological exploration method for an existing tunnel according to claim 2, wherein, in the analysis, a forward reflected wave reflected from a position ahead of a front end of the front and rear ends of the measurement section, and a position behind the rear end. A geological exploration method for an existing tunnel, characterized by using at least a backward reflected wave reflected from a tunnel. 5. The geological exploration method for an existing tunnel according to claim 4, wherein the front reflection is a front reflection wave reflected from a measurement section immediately before a front end of the measurement section, and the rear reflection is the measurement result. The back reflection wave reflected from the immediately following measurement section adjacent to the rear end of the section. The ground conditions in each measurement section are the forward reflection wave obtained by the measurement in the immediately following measurement section and the measurement in the immediately preceding measurement section. A geological exploration method for an existing tunnel, characterized by superimposing and analyzing back-reflected waves obtained by the method. 6. The geological information obtained by the geological exploration method for an existing tunnel according to claim 1 is used for a pre-construction pre-investigation of the existing tunnel, such as widening work. Geological exploration method for existing tunnels. 7. A maintenance management method for an existing tunnel, comprising: judging whether or not the cause of deterioration of a tunnel in an existing tunnel is based on ground conditions, and formulating a maintenance measure for a deteriorated portion of the tunnel based on the judgment. The determination as to whether or not the cause of the tunnel deterioration is based on the ground condition is performed based on geological information obtained by applying the geological exploration method for an existing tunnel according to any one of claims 1 to 5. A characteristic maintenance and management method for existing tunnels.