阅读说明：本技术 一种地震预报方法及三维地应力与地倾斜综合探测体 (Earthquake prediction method and three-dimensional ground stress and ground inclination comprehensive detection body ) 是由 范雷彪 于 2021-08-03 设计创作，主要内容包括：本发明涉及一种地震预报方法及三维地应力与地倾斜综合探测体,所述预报方法：在钻探深井中,分别在上段部距钻探深井井口50～200米的位置和钻探深井底部位置选择探测点对地应力进行探测,并作出探测点位置的地应力矢量图,两个探测点的间距为300～1000米；两个地应力矢量图上对应的两条射线相互间呈发散状,顺着两合力的反方向延伸,可找到交汇点,此点就是应力源所在。其优点是：将设备设置在钻探深井中可避免很多地面干扰因素,将地倾斜和地应力两种信息设在同一个观测体内进行综合观测分析,两种信息互为佐证,并在地下不同深度使用两套独立的观测体同步观测找到地应力的来源和指向,能够准确作出地震预报。(The invention relates to an earthquake prediction method and a three-dimensional ground stress and ground inclination comprehensive detector, wherein the prediction method comprises the following steps: in a deep drilling well, respectively selecting detection points at the position 50-200 meters away from the well mouth of the deep drilling well and the bottom of the deep drilling well on the upper section to detect the ground stress, and making a ground stress vector diagram of the detection points, wherein the distance between the two detection points is 300-1000 meters; the two corresponding rays on the two ground stress vector diagrams are mutually diverged and extend along the opposite direction of the two resultant forces, so that an intersection point can be found, and the point is the stress source. The advantages are that: the device is arranged in a deep drilling well, so that a plurality of ground interference factors can be avoided, two kinds of information of the ground inclination and the ground stress are arranged in the same observation body for comprehensive observation and analysis, the two kinds of information are mutually adjuvanted, two sets of independent observation bodies are used for synchronous observation at different underground depths to find the source and the direction of the ground stress, and the earthquake prediction can be accurately made.)

1. A seismic forecasting method is characterized by comprising the following steps: in a deep drilling well, respectively selecting detection points at the position 50-200 meters away from the well mouth of the deep drilling well and the bottom of the deep drilling well on the upper section to detect the ground stress, and making a ground stress vector diagram of the detection points, wherein the distance between the two detection points is 300-1000 meters; the two corresponding rays on the two ground stress vector diagrams are mutually diverged and extend along the opposite direction of the two resultant forces, so that an intersection point can be found, and the point is the stress source.

2. A method of seismic forecasting as claimed in claim 1, wherein: the depth of the deep drilled well is more than 420 meters.

3. A method of seismic forecasting as claimed in claim 1, wherein: the ground stress is the resultant of the transverse ground stress and the longitudinal stress at the corresponding position.

4. A method of seismic forecasting as claimed in claim 1, wherein: the ground inclination is detected at the detection point, and if the ground inclination is consistent with the action direction of the ground stress, the reliability of the detected ground stress is high.

5. A method of seismic forecasting as claimed in claim 1, wherein: the device for detecting the ground stress at the detection point is a three-dimensional ground stress and ground inclination comprehensive detection body.

6. The three-dimensional ground stress and ground inclination integrated probe in the earthquake prediction method according to claim 5, wherein: the device comprises a first transverse ground stress detection mechanism, a second transverse ground stress detection mechanism, a longitudinal stress strain detection mechanism and a ground inclination detection device, and is characterized in that: the first transverse ground stress detection mechanism and the second transverse ground stress detection mechanism are identical in structure and are composed of a motor, a guiding walking positioning mechanism arranged at the rear end of the motor, a lead screw connected to a motor shaft, two sets of cantilever clamping mechanisms arranged on the lead screw and a pressure sensor arranged at the jacking end of the cantilever clamping mechanisms, the cantilever clamping mechanisms adopt four-bar mechanisms, embedded jacking cones are arranged at the jacking ends of the cantilever clamping mechanisms at the connecting rod hinge points of the four-bar mechanisms, the two sets of cantilever clamping mechanisms are vertically distributed in an up-and-down direction of 90 degrees, and a limiting frame is arranged outside each set of cantilever clamping mechanisms; the second transverse ground stress detection mechanism is positioned below the first transverse ground stress detection mechanism and keeps a distance, the longitudinal stress strain detection mechanism is a set of extensometer which is vertically arranged in a longitudinal direction, a heavy ball of the extensometer is lifted and placed on the second transverse ground stress detection mechanism through a bowl-shaped support, and a displacement sensor of the longitudinal stress strain detection mechanism is connected with the first transverse ground stress detection mechanism; the ground inclination detection device comprises a sleeve, the top of the sleeve is fixed with a second transverse ground stress detection mechanism, a photoelectric receiving disc is fixedly connected to the bottom of the sleeve, a circular arc disc is connected to the middle of the lower end of the second transverse ground stress detection mechanism, the circular arc disc is hung in the sleeve, a small hole is formed in the center of the circular arc disc, a steel ball is placed on the circular arc disc, a thin pipe penetrates through the center of the steel ball and extends out of the small hole of the circular arc disc, a power line is connected to the upper end of the thin pipe, and a laser generator is hung at the lower end of the thin pipe.

7. The integrated three-dimensional ground stress and ground inclination probe of claim 6, wherein: the second transverse ground stress detection mechanism is connected with the first transverse ground stress detection mechanism through a soft rope.

8. The integrated three-dimensional ground stress and ground inclination probe of claim 6, wherein: the guiding walking positioning mechanism adopts a four-wheel positioning mechanism and consists of four guiding wheel mechanisms, each guiding wheel mechanism consists of a guiding wheel supporting cylinder, a guiding wheel support arranged in the guiding wheel supporting cylinder, a jacking spring arranged in the guiding wheel supporting cylinder and a trapezoidal guiding wheel arranged at the outer end part of the guiding wheel support, the four guiding wheel mechanisms are connected end to end and are arranged on a motor tail shell in a square shape, the middle part of the guiding wheel supporting cylinder of each guiding wheel mechanism is hinged with the motor tail shell through a rotating shaft, and the tails of the opposite guiding wheel mechanisms are connected through a spring.

9. The integrated three-dimensional ground stress and ground inclination probe of claim 6, wherein: the periphery of the bowl-shaped support is connected with a support, a guide sleeve is fixed at the top end of the support, and an indium steel rod of the telescopic instrument penetrates through the guide sleeve.

10. The integrated three-dimensional ground stress and ground inclination probe of claim 6, wherein: and a displacement sensor of the telescopic instrument is fixedly connected with the lower end of the limiting frame at the lower part of the first transverse ground stress detection mechanism by a soft rope.

Technical Field

The invention relates to an earthquake prediction method and a three-dimensional ground stress and ground inclination comprehensive detector, belonging to the technical field of earthquake detection and prediction.

Background

Although the ground inclination and ground stress means are provided in the earthquake precursor observation, the two means are in independent operation states and in a battle mode, and in the earthquake induction period, various precursor information appears in an interlaced mode and various information coexist. For a single observation station, even if such information is acquired, a passive situation often occurs, and the reliability and the reality of the acquired information are not judged accurately, so that the embarrassing situation occurs. Secondly, the existing observation instruments are often not in the same region, and the observation data have no internal relevance, lack contrast and call relation, and lack reference basis in information judgment.

On the other hand, observation of transverse ground stress in ground stress detection is easy to realize, observation difficulty of longitudinal ground stress is high, a method for synchronously detecting transverse and longitudinal stresses is not formed at present, and the situation needs to be changed urgently because the problem that the source and the direction of ground stress are determined by using single ground stress and ground surface inclination observation data which are important information required by earthquake prediction cannot be solved, and the significance of obtaining the index for earthquake prediction is high. The comprehensive ground stress and the ground inclination change generated by the comprehensive ground stress are mastered, and the method is a main way for acquiring the index and further has an active effect on recognizing the regular characteristics of the pregnancy period.

Disclosure of Invention

The invention aims to provide an earthquake forecasting method and a three-dimensional comprehensive ground stress and ground inclination detector, which are used for carrying out comprehensive observation analysis by arranging two pieces of information of ground inclination and ground stress in the same observation body, wherein the two pieces of information are mutually adjuvanted, and synchronously observing and finding out the source and the direction of the ground stress by using two sets of independent observation bodies at different underground depths so as to accurately forecast an earthquake.

The technical scheme of the invention is as follows:

an earthquake prediction method comprises the following steps: in a deep drilling well, respectively selecting detection points at the position 50-200 meters away from the well mouth of the deep drilling well and the bottom of the deep drilling well on the upper section to detect the ground stress, and making a ground stress vector diagram of the detection points, wherein the distance between the two detection points is 300-1000 meters; the two corresponding rays on the two ground stress vector diagrams are mutually diverged and extend along the opposite direction of the two resultant forces, so that an intersection point can be found, and the point is the stress source.

The depth of the deep drilled well is more than 420 meters;

the ground stress is the resultant of transverse ground stress and longitudinal stress of the corresponding position;

detecting the ground inclination at the detection point, wherein if the ground inclination is consistent with the action direction of the ground stress, the reliability of the detected ground stress is high;

the device for detecting the ground stress at the detection point is a three-dimensional ground stress and ground inclination comprehensive detection body.

The three-dimensional ground stress and ground inclination comprehensive detector in the earthquake forecasting method comprises a first transverse ground stress detection mechanism, a second transverse ground stress detection mechanism, a longitudinal stress strain detection mechanism and a ground inclination detection device, and is characterized in that: the first transverse ground stress detection mechanism and the second transverse ground stress detection mechanism are identical in structure and are composed of a motor, a guiding walking positioning mechanism arranged at the rear end of the motor, a lead screw connected to a motor shaft, two sets of cantilever clamping mechanisms arranged on the lead screw and a pressure sensor arranged at the jacking end of the cantilever clamping mechanisms, the cantilever clamping mechanisms adopt four-bar mechanisms, embedded jacking cones are arranged at the jacking ends of the cantilever clamping mechanisms at the connecting rod hinge points of the four-bar mechanisms, the two sets of cantilever clamping mechanisms are vertically distributed in an up-and-down direction of 90 degrees, and a limiting frame is arranged outside each set of cantilever clamping mechanisms; the second transverse ground stress detection mechanism is positioned below the first transverse ground stress detection mechanism and keeps a distance, the longitudinal stress strain detection mechanism is a set of extensometer which is vertically arranged in a longitudinal direction, a heavy ball of the extensometer is lifted and placed on the second transverse ground stress detection mechanism through a bowl-shaped support, and a displacement sensor of the longitudinal stress strain detection mechanism is connected with the first transverse ground stress detection mechanism; the ground inclination detection device comprises a sleeve, the top of the sleeve is fixed with a second transverse ground stress detection mechanism, a photoelectric receiving disc is fixedly connected to the bottom of the sleeve, a circular arc disc is connected to the middle of the lower end of the second transverse ground stress detection mechanism, the circular arc disc is hung in the sleeve, a small hole is formed in the center of the circular arc disc, a steel ball is placed on the circular arc disc, a thin pipe penetrates through the center of the steel ball and extends out of the small hole of the circular arc disc, a power line is connected to the upper end of the thin pipe, and a laser generator is hung at the lower end of the thin pipe.

The second transverse ground stress detection mechanism is connected with the first transverse ground stress detection mechanism by a soft rope;

the guiding walking positioning mechanism adopts a four-wheel positioning mechanism and consists of four guiding wheel mechanisms, each guiding wheel mechanism consists of a guiding wheel supporting cylinder, a guiding wheel bracket arranged in the guiding wheel supporting cylinder, a jacking spring arranged in the guiding wheel supporting cylinder and a trapezoidal guiding wheel arranged at the outer end part of the guiding wheel bracket, the four guiding wheel mechanisms are connected end to end and are arranged on a motor tail shell in a square shape, the middle part of the guiding wheel supporting cylinder of each guiding wheel mechanism is hinged with the motor tail shell through a rotating shaft, and the tails of the opposite guiding wheel mechanisms are connected through a spring;

the limiting frame is fixed with the motor shell;

the periphery of the bowl-shaped support is connected with a support, a guide sleeve is fixed at the top end of the support, and an indium steel rod of the telescopic instrument penetrates through the guide sleeve;

and a displacement sensor of the telescopic instrument is fixedly connected with the lower end of the limiting frame at the lower part of the first transverse ground stress detection mechanism by a soft rope.

The invention has the advantages that: the device is arranged in a deep drilling well, so that a plurality of ground interference factors can be avoided, the working principle of a telescopic instrument and ground inclination is used for reference, the device is applied to a vertical exploratory well, two kinds of information of ground inclination and ground stress are arranged in the same observation body for comprehensive observation and analysis, the two kinds of information are mutual evidences, the source and the direction of the ground stress can be found by using two sets of independent observation bodies to synchronously observe at different underground depths, and the earthquake prediction can be accurately made.

Drawings

FIG. 1 is a schematic structural view of the upper half of the apparatus of the present invention;

FIG. 2 is a schematic view of the lower half of the apparatus of the present invention;

FIG. 3 is a schematic structural view of a four-wheel positioning mechanism;

fig. 4 is a schematic structural view of a photo-receiving tray;

fig. 5 is a schematic diagram of the seismic forecasting method of the present invention.

Fig. 1 and 2 are in abutting relationship, with the upper end of fig. 2 being joined to the lower end of fig. 1.

In the figure: 1-drilling a deep well, 2-a first transverse ground stress detection mechanism, 3-a longitudinal stress strain detection mechanism, 4-a second transverse ground stress detection mechanism, 5-a ground inclination detection device, 6-a first set of detection body, 7-a second set of detection body, 21-a guide walking positioning mechanism, 22-a motor, 23-an east-west direction limit frame, 24-an east-west direction cantilever clamping mechanism, 25-a lead screw, 26-an east-west direction pressure sensor, 27-a south-north direction limit frame, 28-a south-north direction pressure sensor, 29-a south-north direction cantilever clamping mechanism, 31-a displacement sensor, 32-a guide sleeve, 33-a support, 34-an indium steel rod, 35-a heavy ball of a telescopic instrument, 36-a bowl-shaped support and 51-a power line, 52-steel ball, 53-arc disc, 54-laser generator, 55-sleeve, 56-photoelectric receiving disc, 211-guide wheel supporting cylinder, 212-guide wheel bracket, 213-rotating shaft, 214-tightening spring, 215-trapezoidal guide wheel, 216-spring and 561-photodiode.

Detailed Description

Referring to the attached drawings 1 and 2, the three-dimensional ground stress and ground inclination comprehensive detector comprises a first transverse ground stress detection mechanism 2, a second transverse ground stress detection mechanism 4, a longitudinal stress strain detection mechanism 3 and a ground inclination detection device 5, wherein the first transverse ground stress detection mechanism and the second transverse ground stress detection mechanism are identical in structure and are composed of a motor 22, a guiding walking positioning mechanism 21 arranged at the rear end of the motor, a lead screw 25 connected to a motor shaft, two sets of cantilever clamping mechanisms arranged on the lead screw and a pressure sensor arranged at the jacking end of the cantilever clamping mechanisms, the cantilever clamping mechanisms adopt four-bar mechanisms, an embedded jacking cone is arranged at the jacking end of the cantilever clamping mechanisms at the connecting bar hinge points of the four-bar mechanisms, the two sets of cantilever clamping mechanisms are vertically distributed in an upper 90-degree mode, and vertically distributed, and the two sets of cantilever clamping mechanisms are respectively an east-west cantilever clamping mechanism 24 positioned above and a south-north-south cantilever clamping mechanism positioned below the east-west cantilever clamping mechanisms The device comprises a directional cantilever clamping mechanism 29, wherein a east-west pressure sensor 26 is arranged at the top tight end of the east-west cantilever clamping mechanism, a south-north pressure sensor 28 is arranged at the top tight end of the south-north cantilever clamping mechanism, east-west limiting frames 23 are arranged at two sides of the east-west cantilever clamping mechanism, south-north limiting frames 27 are arranged at two sides of the south-north cantilever clamping mechanism, and the east-west limiting frames and the south-north limiting frames are fixed with a motor shell; the second transverse ground stress detection mechanism is positioned below the first transverse ground stress detection mechanism and keeps a distance, the longitudinal stress and strain detection mechanism is a set of telescopic instruments vertically arranged in the longitudinal direction, a heavy ball 35 of each telescopic instrument is lifted and placed on the second transverse ground stress detection mechanism through a bowl-shaped support 36, a support 33 is connected to the periphery of the bowl-shaped support, a guide sleeve 32 is fixed at the top end of each support, and an indium steel rod 34 of each telescopic instrument penetrates through the guide sleeve; the displacement sensor 31 of the expansion instrument is fixedly connected with the lower end of the north-south limiting frame of the first transverse ground stress detection mechanism by a soft rope. The ground inclination detection device comprises a sleeve 55, the diameter of the sleeve is 12 cm, the length of the sleeve is 4 m, the top of the sleeve is fixedly connected with the lower end of a south-north limiting frame of a second transverse ground stress detection mechanism, a photoelectric receiving disc 56 is fixedly connected to the bottom of the sleeve, a circular arc disc 53 is connected to the middle of the lower end of the second transverse ground stress detection mechanism and hung in the sleeve, a small hole is formed in the center of the circular arc disc, a steel ball 52 is placed on the circular arc disc, a thin tube penetrates through the center of the steel ball and extends out of the small hole of the circular arc disc, the upper end of the thin tube is connected with a power line 51, and a laser generator 54 is hung at the lower end.

Referring to fig. 3, the guiding and traveling positioning mechanism is a four-wheel positioning mechanism and is composed of four guiding wheel mechanisms, each guiding wheel mechanism is composed of a guiding wheel supporting cylinder 211, a guiding wheel support 212 installed in the guiding wheel supporting cylinder, a tightening spring 214 installed in the guiding wheel supporting cylinder and a trapezoidal guiding wheel 215 installed at the outer end part of the guiding wheel support, the four guiding wheel mechanisms are connected end to end and are installed on a motor tail shell in a square arrangement, the middle part of a sleeve of each guiding wheel mechanism is hinged to the motor tail shell through a rotating shaft 213, and the tails of the opposite guiding wheel mechanisms are connected through a spring 216.

Referring to fig. 4, the photo receiver disc 56 is assembled by photodiodes 561, which are arranged on a plurality of concentric circles on the photo receiver disc, and each photodiode is individually connected to form a loop.

The design idea of the three-dimensional ground stress and ground inclination comprehensive detector is as follows: two fixing bodies (each fixing body is realized by a set of clamping mechanism) are formed on the wall of a well for drilling the deep well 1, and corresponding equipment is installed by utilizing the firm action of the fixing bodies. The two fixing bodies are respectively a first transverse ground stress detection mechanism 2 and a second transverse ground stress detection mechanism 4, the length of a single transverse ground stress detection mechanism is about 1.5 m, the single transverse ground stress detection mechanism is respectively composed of two motors and four cantilever clamping mechanisms, and each fixing body firmly fixes four pressure sensors and the mechanisms on a well wall by utilizing the jacking action of the cantilever clamping mechanisms. The total length of the detection body is about 35 meters, the first transverse ground stress detection mechanism and the second transverse ground stress detection mechanism are suspended and fixed in the air of the exploration well, a span of about 30 meters is arranged between the two transverse ground stress detection mechanisms, the longitudinal stress strain detection mechanism is installed in the space, and a set of laser detection device is suspended at the lower part of the lower fixing body and used for mastering the inclination condition of the exploration well in the large-terrain change activity.

The method of the invention comprises the following steps: in a deep drilling well, detecting the ground stress by selecting detection points at the position of 200 meters away from the wellhead of the deep drilling well and the bottom of the deep drilling well on the upper section respectively, and making a ground stress vector diagram of the detection point positions, wherein the distance between the two detection points is 1000 meters; the two corresponding rays on the two ground stress vector diagrams are mutually diverged and extend along the opposite direction of the two resultant forces, so that an intersection point can be found, and the point is the stress source.

Referring to fig. 5, according to the method of the present invention, two sets of three-dimensional ground stress and ground inclination comprehensive probes are installed in a deep drilling well, a first set of probe 6 is installed at a position which is 1240 meters away from a wellhead of the deep drilling well, a second set of probe 7 is installed at a position which is 200 meters away from the wellhead of the deep drilling well, and two sets of devices are spaced by about 1000 meters.

The equipment installation of the comprehensive detection body of the three-dimensional ground stress and the ground inclination comprises the following steps:

firstly, an upright derrick with the height of about 6 meters is arranged above a well mouth of a deep drilling well, and a first set of detection bodies are placed to a preset position by using a steel wire rope and then are fixed by starting motors one by one. Because the length of single probe is 35 meters, and the direct transfer degree of difficulty is great, consequently connects upper and lower two fixed bodies with chain (soft rope) connected mode, makes whole device become the flexible connection form and transfers. When the lower fixing body is placed to a preset point, the lower fixing body is fastened, and then the upper fixing body is placed by a certain size (a margin is reserved between the upper fixing body and the lower fixing body), so that direct acting force transmission cannot be formed between the two points. Considering the inconvenience in the installation of the overlong indium steel rod, the indium steel rod is cut into four sections, and each section is connected section by using a connecting sleeve in the lowering process. In-process of transferring at the detection body, because direction walking positioning mechanism is installed to the motor rear end of every fixed body, direction walking positioning mechanism's leading wheel support pushes trapezoidal leading wheel and pastes tightly with the wall of a well of probing deep well under the effect of top tension spring, four trapezoidal leading wheels evenly distributed, down along the wall of a well, make the detection body can transfer with the position of settlement, when transferring the rear starter motor that targets in place, four trapezoidal leading wheels can form four reverse action moments, the restriction equipment transversely rotates, can ensure that the motor has sufficient reaction force to support the motor and rotate. The motor rotates and drives the lead screw 25 to rotate, and the east-west cantilever clamping mechanism is driven to expand outwards in the region limited by the east-west limiting frame, so that the embedded jacking cone at the jacking end of the east-west cantilever clamping mechanism is embedded into the well wall, and meanwhile, the south-north cantilever clamping mechanism expands outwards in the region limited by the south-north limiting frame, so that the embedded jacking cone at the jacking end of the south-north cantilever clamping mechanism is embedded into the well wall, and the jacking end is provided with the pressure sensors which are arranged in the east-west direction and the south-north direction and are abutted against the well wall in an embedded mode.

The working principle of the longitudinal stress-strain detection mechanism is as follows:

between the span of the two fixed bodies, a longitudinal stress-strain detection mechanism is arranged, the total length of the detection mechanism is about 30 meters, and the detection mechanism is equivalent to a set of extensometer which is vertically arranged in the longitudinal direction. In order to ensure that the 'telescopic instrument' can always keep a vertical state, the equipment cannot be adjusted at any time during installation like the ground in consideration of special conditions of a drilling environment, and the equipment also needs to be adaptive to various changes in observation and has a self-adjusting function. The structure is therefore significantly different from the structure of a floor level telescope at the bottom and top. Firstly, the bottom is taken as a fixed end and is not fixed on a frame of a motor of a second transverse ground stress detection mechanism, but a bowl supporting and weighting ball mode is adopted to lift the fixed end; secondly, the indium steel rod needs to be guided by a guide sleeve. In order to ensure the verticality of the displacement sensor, the displacement sensor is not directly fixed on the north-south limiting frame of the first transverse ground stress detection mechanism, but a lifting rope extends out of the frame, and the displacement sensor is hung by the lifting rope. The design can make indium steel pole and displacement sensor remain the vertically throughout, can prevent effectively that the slope from appearing in the indium steel pole mistake and displacement sensor inner wall from taking place the wall phenomenon of rubbing, has ensured the normal continuation of observation precision.

Working principle of the ground inclination detection device:

when the photoelectric receiving disc is inclined to the ground, the steel ball can shake in the circular arc disc after the inclination trace reaches a certain value, and the landing of the light beam on the photoelectric receiving disc is different due to different swing amplitudes. Assuming a beam shift of 0.4cm (0.4 cm shift is well within the exact order of the laser technique), tg β =0.4/400=1.74 × 10, calculated according to a trigonometric function^-5Then the steel ball has a value of 1.74X 10^-5The change in inclination of the degrees can be displayed on the device.

The photoelectric receiving disk is formed by assembling photodiodes, a plurality of photodiodes are distributed on a plurality of concentric circumferences of the photoelectric receiving disk for 10 circles, the distance between every circle is 0.4cm, and a plurality of diodes, namely 400, are independently connected to form a loop. The direction and angle of the tilt can be known by different diodes being switched on for different beam spot positions.

Acquiring three-dimensional ground stress:

the transverse and longitudinal ground stress at a certain position can be known, and the three-dimensional ground stress condition can be obtained. In the design scheme of the invention, the transverse crustal stress is directly obtained by a pressure sensor, while the longitudinal crustal stress is not directly obtained, but the elastic modulus value of the crustal sample obtained during drilling is obtained by a laboratory through knowing the stress strain between the upper fixing body and the lower fixing body, so that the stress magnitude can be roughly obtained (certain deviation exists in accuracy, but quantification is undoubted).

If the stress source is transmitted in the underground deep, the stress source will generate an increasing amount to the pressure sensor of the fixed body when acting in the transverse direction, and a vector diagram is made according to the amount and the longitudinal stress value, and the resultant force is the direction of the ground stress.

Referring to fig. 5, the resultant force measured by the upper and lower sets of probes will be different in magnitude due to different positions, so that the two ray lines must be divergent and extend in the opposite direction of the two resultant forces to find the junction where the stress source is located. The direction of the underground stress field source and the stress direction thereof can be determined, and the increase and decrease change of the magnitude of the stress field source (the change condition of the intersection of two lines, the stress increase included angle is also increased) can be used as an important basis for judging whether the pregnancy phenomenon or the general stress change occurs. If the pregnancy earthquake phenomenon is suspected, the method can preliminarily determine the depth and the position of the earthquake source, and the possibility of earthquake occurrence is judged with convincing power by combining with the relevant knowledge of earthquake geology on the basis.

The advantage of installing stress detection and inclination observation on one set of instrument simultaneously is that the observation results of the two can be used as evidence for mutual evidencing, and when the observed ground inclination is consistent with the action direction of the ground stress (namely the inclination direction is the same as the action direction of the ground stress), the information at the moment is absolutely originated from the underground depth, and the credibility is high. In addition, interference of various uncertain factors of the earth surface and influence of solid tide action (the deeper the solid tide action is, the weaker the solid tide action is), and the analysis and application of the data are clear.

Because the ground stress of the underground depth is strong, the signal of the detection interval is strong, the detection body does not need to be set with higher precision like the ground, and the detection body is more beneficial to the operation and maintenance of instruments.

Detection mode of ground inclination:

assuming that a stress field is formed at a position underground, the stress field is lifted under the action of the earth stress and has a state of inclining towards east and west, and then the reaction on the detection body is that the east end inclines upwards and the west end inclines downwards. At this time, the steel ball in the arc disk is swung to the west end, and the beam spot is deviated to the east end. The west tilt angle can be accurately determined according to the different current loops generated by the light beam spot according to the different irradiation positions of the light beam spot on the receiving disc.

Since the ground inclination obtained in this way is closely connected with the action of ground stress, and the change of longitudinal ground strain is combined, if the stress strain recorded by the 'extensometer' is negative and continuously increases, the west inclination of the ground surface in the lifted state can be proved.

The direction and speed of the ground inclination are closely related to the ground stress activity, and the understanding of the interaction and dependence relationship of the ground inclination plays a crucial role in analyzing and judging the earthquake origin moment. The previous experience accumulation shows that the ground inclination value in the pregnancy period is a continuous process, the inclination value reaches 3-5 degrees after the earthquake occurs after the accumulation of a certain period, and the experience values are compared with the obtained observation values to predict the earthquake occurrence time, so that the method is an effective way.

In the comprehensive detection body for the three-dimensional ground stress and the ground inclination, the deformation characteristics of the ground are judged by observing the inclination change of the well wall, and no matter how the ground deforms (fluctuation, distortion, slippage and dislocation), corresponding 'traces' are necessarily left on the detection well wall. The change condition of the earth is known by mastering the trace of the well wall, the observed earth inclination is intuitive deformation, and the non-solid tide elastic deformation is intuitive, obvious and reliable for earthquake prediction.

The invention can directly find out the stress origin and the inclination direction of the earth, can roughly determine the origin seismic place during the earthquake prediction, and then determine the origin seismic time through the duration of the change of the inclination value, thus two of the three elements of the earthquake can be obtained during the earthquake prediction.