A monitoring method for displacement patterns of large-displacement strike-slip faults

Abstract

The present application discloses a method for monitoring the displacement mode of a large-deformation strike-slip fault, belonging to the technical field of rock engineering; the monitoring method includes: drilling a deep hole through the fault along the depth direction of the fault, and sequentially arranging a plurality of initial monitoring points at intervals along the length direction of the deep hole through the fault, and the distance between the projections of adjacent initial monitoring points in the first direction is a preset distance; respectively monitoring the initial azimuth angles of the deep hole through the fault at a plurality of initial monitoring points; in the case of displacement of the strike-slip fault, sequentially determining the measured monitoring points in the deep hole through the fault based on the preset distance; respectively monitoring and obtaining the measured azimuth angles at the measured monitoring points; based on the preset distance, the initial azimuth angles, the initial azimuth angles, the measured azimuth angles, and the measured azimuth angles, obtaining the dislocation translation amount at the initial monitoring points and the in-hole distance between adjacent measured monitoring points in the deep hole through the fault. The monitoring method provided by the present application can realize the monitoring of the displacement mode of a large-deformation strike-slip fault in the fault thickness direction.

Description

Technical Field

[0001] This application belongs to the technical field of rock mass engineering, and particularly relates to a method for monitoring the displacement mode of large-deformation strike-slip faults. Background Art

[0002] The dislocation of strike-slip faults has a profound impact on the stability of rock mass engineering and structures in areas with complex geological conditions. Therefore, accurately identifying the distribution pattern of the dislocation translation amount of strike-slip faults is crucial for the selection of rock mass engineering measures and the design of structures. However, there is currently no good method for identifying the dislocation translation amount along the thickness direction of strike-slip faults.

[0003] The measurement of faults mainly includes the measurement of fault displacement with small deformation and the measurement of fault displacement with large deformation. Among them, for the measurement of fault displacement with small deformation, methods such as invar tape baseline measurement, precise leveling measurement, high-precision triangulation measurement, laser ranging, resistance wire steel string ranging, communicating pipe measurement, quartz extensometer, and ground tilt measurement are often used. For the large-deformation fault displacement, methods such as observation stations, GNSS, or deep-hole displacement monitoring methods are mostly used. However, none of the above methods can obtain the displacement distribution data and laws along the fault depth direction, that is, the thickness direction. Summary of the Invention

[0004] This application provides a method for monitoring the displacement mode of large-deformation strike-slip faults, aiming to at least solve to a certain extent the technical problem that the displacement mode of large-deformation strike-slip faults in the thickness direction cannot be monitored. For this purpose,

[0005] The method for monitoring the displacement mode of large-deformation strike-slip faults provided by the embodiments of this application includes:

[0006] Drill a deep hole through the fault along the fault depth direction, and sequentially set a plurality of initial monitoring points at intervals along the length direction of the deep hole through the fault. The distance between the projections of the adjacent ith initial monitoring point and the (i + 1)th initial monitoring point in the first direction is a preset distance ΔH i ;

[0007] Monitor the initial azimuth angle θ of the deep hole through the fault at each of the plurality of initial monitoring points 0,i ;

[0008] When the strike-slip fault displaces, based on the preset distance ΔH i successively determine the measured monitoring points in the deep hole through the fault;

[0009] Monitor and obtain the measured azimuth angle θ at each of the measured monitoring points n,i ;

[0010] Based on the preset distance ΔH i 、the initial azimuth angle θ 0,i 、initial azimuth angle θ0,i+1 、Measured azimuth angle θ n,i and the measured azimuth angle θ n,i+1 , obtain the dislocation translation amount S of the nth monitoring at the (i + 1)th initial monitoring point n,i and the in-hole distance ΔL between the adjacent ith measured monitoring point and the (i + 1)th measured monitoring point in the fault-crossing deep hole n,i ;

[0011] Based on the dislocation translation amount S n,i and the in-hole distance ΔL n,i , obtain the relationship curve between the total dislocation translation amount S n and the drilling depth L of the fault-crossing deep hole n ;

[0012] Among them, let the first initial monitoring point be the reference point without strike-slip displacement, i be the order of the initial monitoring point and the measured monitoring point, and n be the frequency of monitoring the strike-slip displacement.

[0013] Furthermore, drilling the fault-crossing deep hole along the fault depth direction includes:

[0014] According to the fault distribution state, set ear holes on both sides of the fault respectively;

[0015] Drill holes along the fault depth direction to connect the ear holes on both sides of the fault, forming a fault-crossing deep hole.

[0016] Furthermore, a flexible casing is installed in the fault-crossing deep hole, and the multiple initial monitoring points are arranged at intervals along the length direction of the fault-crossing deep hole in the flexible casing.

[0017] Furthermore, the flexible casing is a flexible PVC casing or a spring casing.

[0018] Furthermore, monitoring the initial azimuth angle of the fault-crossing deep hole at the multiple initial monitoring points includes:

[0019] Measuring the initial azimuth angle of the fault-crossing deep hole at the multiple initial monitoring points in turn along the length direction of the fault-crossing deep hole by an azimuth angle monitoring device.

[0020] Furthermore, sequentially determining the measured monitoring points in the fault-crossing deep hole based on the preset spacing ΔH i includes:

[0021] Taking the spacing of the projection in the first direction as the preset spacing ΔH i as the standard, along the length direction of the flexible casing, starting from the second initial monitoring point, sequentially determine the positions of the measured monitoring points in the fault-crossing deep hole.

[0022] Further, the azimuth monitoring device includes: an azimuth sensor.

[0023] Further, the dislocation translation amount S at the (i + 1)-th initial monitoring point n,i and the in-hole distance ΔL n,i have a conversion model as follows:

[0024]

[0025]

[0026]

[0027] wherein, ΔL 0,i is the distance between two adjacent initial monitoring points, and ΔL n,i is the distance between two adjacent measured monitoring points.

[0028] Further, the total dislocation translation amount S n and the borehole depth L n have a conversion model as

[0029]

[0030]

[0031] wherein, N is the number of monitoring points.

[0032] Further, the first direction is the fault thickness direction or the fault plane dip direction.

[0033] The embodiments of the present application at least have the following beneficial effects:

[0034] The large-deformation strike-slip fault displacement mode monitoring method provided by the embodiments of the present application drills a deep hole through the fault along the fault depth direction, equally-spacedly arranges monitoring points, and respectively monitors the monitoring azimuth angles before and after the strike-slip fault displaces to obtain the azimuth deviation, so as to obtain the dislocation translation amount of each monitoring point based on the preset monitoring point interval, thereby being able to obtain the distribution mode of the large-deformation strike-slip fault displacement in the fault depth direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0036] Figure 1The schematic diagram of the borehole orientation of the large-deformation strike-slip fault displacement mode monitoring method in the embodiments of the present application is shown;

[0037] Figure 2 shown Figure 1 the curve of the borehole depth-azimuth angle relationship of the large-deformation strike-slip fault displacement mode monitoring method in;

[0038] Figure 3 shown Figure 1 the curve of the borehole depth-displacement translation relationship of the large-deformation strike-slip fault displacement mode monitoring method in;

[0039] Figure 4 shown Figure 1 the schematic diagram of the principle of the large-deformation strike-slip fault displacement mode monitoring method in. Specific embodiments

[0040] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0041] In addition, the present application may repeat reference numerals and / or reference letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present application provides examples of various specific processes and materials, but those of ordinary skill in the art may be aware of the application of other processes and / or the use of other materials.

[0042] The present application will be described below in conjunction with the accompanying drawings and with reference to specific embodiments:

[0043] Refer to Figure 1 、 Figure 2 、 Figure 3 and Figure 4 , the large-deformation strike-slip fault displacement mode monitoring method provided by the embodiments of the present application includes:

[0044] Drill a deep hole through the fault along the fault depth direction, and sequentially set a plurality of initial monitoring points at intervals inside along the length direction of the deep hole through the fault. The distance between the projections of the adjacent i-th initial monitoring point and the (i + 1)-th initial monitoring point in the first direction is a preset distance ΔH i ;

[0045] Monitor the initial azimuth angle θ of the deep hole through the fault at each of the plurality of initial monitoring points respectively 0,i ;

[0046] In the case of displacement occurring on a strike-slip fault, at a preset spacing ΔH i successively determine the actually measured monitoring points within the deep hole crossing the fault;

[0047] respectively monitor the actually measured azimuth angle θ n,i at the actually measured monitoring points;

[0048] Based on the preset spacing ΔH i the initial azimuth angle θ 0,i the initial azimuth angle θ 0,i+1 the actually measured azimuth angle θ n,i and the actually measured azimuth angle θ n,i+1 obtain the dislocation translation amount S n,i of the nth monitoring at the (i + 1)th initial monitoring point and the in-hole distance ΔL n,i within the deep hole crossing the fault between the adjacent ith actually measured monitoring point and the (i + 1)th actually measured monitoring point;

[0049] Based on the dislocation translation amount S n,i and the in-hole distance ΔL n,i obtain the relationship curve between the total dislocation translation amount S n and the drilling depth L n of the deep hole crossing the fault;

[0050] wherein, let the first initial monitoring point be the reference point without strike-slip displacement, i is the sequence number of the initial monitoring point and the actually measured monitoring point, and n is the frequency of monitoring the strike-slip displacement.

[0051] In some embodiments, in order to drill the deep hole crossing the fault, ear holes can be respectively arranged on both sides of the fault according to the fault distribution state, and then drill holes along the depth direction of the fault, that is, the thickness direction, to connect the ear holes on both sides of the fault, that is, connect ear hole 1 and ear hole 2, to form the deep hole crossing the fault.

[0052] See Figure 4 multiple monitoring points can be arranged at intervals along the length direction within the deep hole crossing the fault for measuring the azimuth angle; considering the strike-slip translation of the fault, translational deformation will occur in the deep hole crossing the fault, and accordingly its length and shape will change, making the positions of the monitoring points also change, which is not conducive to accurately positioning the monitoring points after translation and resulting in unreliable monitoring structures.

[0053] For this reason, the monitoring points can be divided into initial monitoring points and actually measured monitoring points. The initial monitoring points are the monitoring points arranged in the deep hole crossing the fault after initial drilling. According to the situation after fault exploration, the initial monitoring points can be arranged at intervals according to a certain spacing ΔL 0,i and the initial monitoring points are arranged at intervals, ΔL 0,iThe specific value of can be set according to the actual situation; considering the translational sliding of the fault, the first direction can be set, and the projection of the initial monitoring point in the first direction can be obtained as the positioning reference point to calibrate the initial monitoring point and the measured monitoring point; that is, before and after the strike-slip translation at the end side, the projections of the initial monitoring point and the measured monitoring point in the first direction coincide, so that the position of the measured monitoring point after the strike-slip translation of the fault can be reliably determined based on the initial monitoring point and the first direction, and thus the measured monitoring point can be accurately located based on the characteristics of the strike-slip translation, so as to accurately characterize the translational characteristics before and after the strike-slip.

[0054] See Figure 4 , specifically, for two adjacent monitoring points, that is, the i-th monitoring point and the (i + 1)-th monitoring point, before the strike-slip translation of the fault, they are the initial monitoring points, and the initial azimuth angles θ 0,i and θ 0,i+1 can be monitored, and the initial in-hole distance ΔL 0,i between the two initial monitoring points, and the spacing of the projections in the first direction is the preset spacing ΔH i ; after the strike-slip translation occurs, different parts of the deep borehole of the fault will undergo translational displacements of different degrees, resulting in varying degrees of deformation of the deep borehole. However, since the strike-slip translation is mainly lateral translation and the change in the layer thickness direction is relatively small, it is not considered here. Therefore, the preset spacing ΔH i remains unchanged, but the positions of the initial monitoring points will shift. The transformed monitoring points become the measured monitoring points, but the naming order remains the same. The measured azimuth angles θ n,i and θ n,i+1 , and the initial in-hole distance ΔL n,i .

[0055] During the process of implementing the monitoring of the initial azimuth angles of the multiple monitoring points for the cross-fault deep hole, the initial azimuth angles of the cross-fault deep hole can be measured successively at the multiple monitoring points by an azimuth angle monitoring device along the length direction of the cross-fault deep hole.

[0056] Similarly, during the process of monitoring and obtaining the measured azimuth angles at the measured monitoring points, the measured azimuth angles of the cross-fault deep hole are measured successively at the multiple measured monitoring points by the azimuth angle monitoring device along the cross-fault deep hole after the strike-slip deformation.

[0057] Generally, the azimuth angle monitoring device can be towed along the deep borehole of the fault by a towing rope, or the monitoring operation can be implemented by a robot moving along the deep borehole of the fault.

[0058] It should be noted that the first monitoring point can be set as the reference monitoring point without strike-slip displacement, that is, the positions of the first initial monitoring point and the first measured point coincide.

[0059] To form a stable monitoring environment, a flexible casing is installed in the deep cross-fault hole, and the multiple monitoring points are arranged at equal intervals along the length direction of the deep cross-fault hole in the flexible casing, so as to provide a stable measurement environment for the azimuth measurement device and prevent the rock and soil fragments falling during the fault strike-slip from affecting the measurement; on the other hand, the flexible casing can adapt to the sliding of the fault and produce certain morphological changes to maintain the stability of the measurement environment.

[0060] Generally speaking, the flexible casing can be set as a flexible PVC casing to maintain the stability of the monitoring environment with its good wear and corrosion resistance. It can also be set as a bellows tube to maintain good deformation characteristics.

[0061] It should be noted that after the drilling and the initial monitoring point layout are completed, the preset spacing ΔH i and the position of the first initial monitoring point are known. Starting from the first initial monitoring point and then from the second initial monitoring point, the positions of the measured monitoring points in the deep cross-fault hole can be determined in sequence.

[0062] The specific determination method is as follows: taking the first measured monitoring point as the starting point, moving the azimuth monitoring device along the deep cross-fault hole to obtain a continuous real-time data combination of the real-time azimuth and the real-time in-hole spacing. When the real-time data combination at a certain moment satisfies:

[0063]

[0064] then the point where the azimuth monitoring device is located at this time is the (i + 1)-th measured monitoring point; among them, the first measured monitoring point is known, so the measured azimuth θ n,1 is known. When ΔH1 is known, the second real-time monitoring point can be stably determined, and at the same time, the measured in-hole distance ΔL n,1 and the measured azimuth θ n,2 are determined; and so on, the positions of the subsequent measured monitoring points can be obtained by successive iteration.

[0065] Generally speaking, the azimuth monitoring device can adopt devices such as an electronic compass and an azimuth sensor, and there is no limitation here.

[0066] It is not difficult to find that during the process of determining the measured monitoring points, the azimuth of each measured monitoring point and the in-hole distance between two adjacent measured monitoring points are also determined, so that the dislocation translation amount at each initial monitoring point can be determined based on this. Since the first initial monitoring point does not translate, the dislocation translation amount is 0, and the converted dislocation translation amount starts from the second initial monitoring point.

[0067] Specifically, the dislocation translation amount S n,i at the (i + 1)-th initial monitoring point and the in-hole distance ΔL n,i have the following conversion model:

[0068]

[0069]

[0070]

[0071] Among them, ΔL 0,i is the distance between two adjacent initial monitoring points, and ΔL n,i is the distance between two adjacent actually measured monitoring points.

[0072] The total dislocation translation amount S n and the conversion model of the borehole depth L n is

[0073]

[0074]

[0075] Among them, N is the number of monitoring points.

[0076] Generally, for the convenience of calculation, the first direction can be the fault thickness direction or the fault plane dip direction.

[0077] The embodiments of the present application at least have the following beneficial effects:

[0078] The large deformation strike-slip fault displacement mode monitoring method provided by the embodiments of the present application drills a deep hole through the fault along the fault depth direction, and equally spaced monitoring points are set. The monitoring azimuth angles before and after the strike-slip displacement of the fault are respectively monitored to obtain the azimuth angle deviation. Then, based on the preset monitoring point interval, the dislocation translation amount of each monitoring point is obtained, so that the distribution mode of the large deformation strike-slip fault displacement in the fault depth direction can be obtained.

[0079] In the present application, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may include the direct contact of the first and second features, or may include the situation where the first and second features are not in direct contact but are in contact through other features between them. Moreover, the first feature being "above", "over" and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the first feature is at a higher horizontal height than the second feature. The first feature being "under", "beneath" and "under" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the first feature is at a lower horizontal height than the second feature.

[0080] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present application.

[0081] It should be noted that all directional indications in the embodiments of the present application are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If this specific posture changes, the directional indication will also change accordingly.

[0082] In the present application, unless otherwise clearly defined and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0083] In addition, in the present application, the descriptions such as "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more, unless otherwise clearly and specifically defined.

[0084] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification.

[0085] In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0086] Although the embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of the present application. The scope of the present application is defined by the claims and their equivalents.

Claims

1. A monitoring method for the displacement pattern of large-deformation strike-slip faults, characterized in that, Comprising: Drill a deep hole through the fault along the depth direction of the fault, and sequentially arrange a plurality of initial monitoring points at intervals inside the deep hole through the fault along the length direction of the deep hole through the fault, and the distance between the projections of the adjacent ith initial monitoring point and the (i + 1)th initial monitoring point in the first direction is a preset distance ΔH i ; Monitor the initial azimuth angle θ of the deep hole through the fault at the multiple initial monitoring points respectively 0,i ; In the case of displacement occurring in a strike-slip fault, the actual monitoring points in the deep cross-fault holes are determined in sequence based on a preset spacing ΔH i as the basis; Measure the actual azimuth angle θ at the actual monitoring points respectively n,i ; Based on the preset spacing ΔH i and the initial azimuth angle θ 0,i The initial azimuth angle θ 0,i+1 The measured azimuth angle θ n,i and the measured azimuth angle θ n,i+1 , obtain the dislocation translation amount S of the nth monitoring at the (i + 1)th initial monitoring point n,i and the in-hole distance ΔL between the adjacent ith measured monitoring point and the (i + 1)th measured monitoring point in the cross-fault deep hole n,i ; Based on the dislocation translation amount S n,i and the in-hole distance ΔL n,i , the total dislocation translation amount S n and the drilling depth L of the deep hole crossing the fault n are used to obtain the relationship curve; Among them, the first initial monitoring point is set as the reference point without strike-slip displacement. i is the position of the initial monitoring point and the measured monitoring point, and n is the frequency of monitoring the strike-slip displacement.

2. The large-deformation strike-slip fault displacement pattern monitoring method according to claim 1, characterized in that The drilling of the deep hole through the fault along the depth direction of the fault includes: According to the distribution state of the fault, ear holes are respectively arranged on both sides of the fault; Drill holes along the depth direction of the fault to connect the ear holes on both sides of the fault to form a deep hole through the fault.

3. The large-deformation strike-slip fault displacement pattern monitoring method according to claim 1, characterized in that A flexible casing is installed in the deep hole through the fault, and the multiple initial monitoring points are arranged at intervals along the length direction of the deep hole through the fault in the flexible casing.

4. The large-deformation strike-slip fault displacement pattern monitoring method according to claim 3, wherein The flexible casing is a flexible PVC casing or a spring casing.

5. The large-deformation strike-slip fault displacement pattern monitoring method according to claim 3, characterized in that The monitoring of the initial azimuth angle of the deep hole through the fault at the multiple initial monitoring points includes: Measuring the initial azimuth angle of the deep hole through the fault at the multiple initial monitoring points in sequence along the length direction of the deep hole through the fault by an azimuth angle monitoring device.

6. The large deformation strike-slip fault displacement pattern monitoring method according to claim 5, characterized in that The above-mentioned taking the preset spacing ΔH i as the basis, successively determining the actually measured monitoring points in the deep hole through the fault includes: Taking the spacing of the projections in the first direction as the preset spacing ΔH i as the standard, along the length direction of the flexible casing, starting from the second initial monitoring point, the positions of the actually measured monitoring points in the deep hole through the fault are determined in sequence.

7. The monitoring method for the displacement mode of large-deformation strike-slip faults according to claim 5, characterized in that The azimuth angle monitoring device includes: an azimuth angle sensor.

8. The monitoring method for the displacement mode of large-deformation strike-slip faults according to claim 1, wherein The dislocation translation amount S at the (i + 1)-th initial monitoring point n,i and the in-hole distance ΔL n,i The conversion model is as follows: where, ΔL 0,i is the distance between two adjacent initial monitoring points, and ΔL n,i is the distance between two adjacent actually measured monitoring points.

9. The large deformation strike-slip fault displacement pattern monitoring method according to claim 8, characterized in that The total dislocation translation amount S n and the drilling depth L n The conversion model is Among them, N is the number of monitoring points.

10. The monitoring method for the displacement pattern of large-deformation strike-slip faults according to claim 1, wherein The first direction is the fault thickness direction or the fault plane dip direction.

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