阅读说明：本技术 岩土勘探工程软岩地应力测试装置和软岩地应力测试方法 (Soft rock ground stress testing device and soft rock ground stress testing method for geotechnical exploration engineering ) 是由 韩少鹏 于 2017-09-09 设计创作，主要内容包括：一种岩土勘探工程软岩地应力测试装置以及岩地应力测试,通过钻孔机在围岩的指定位置形成钻孔,在钻孔外形成多个应力传感组件,通过推杆将应力传感组件推入钻孔内指定深度,通过注浆杆向应力传感组件弓形水泥底座的上方空间注浆,从而使应力传感组件的检测面上的砂浆在受到软岩压力的情况下凝固；基于应力传感组件的传感器的读数,确定应力传感组件的地应力,从而建立软岩区域空间力学模型。本发明通过现场量测信息拓展出整个工程范围的初始地应力场,对于指导地应力实测和工程建设更有意义,具有重要的实用价值。(A soft rock ground stress testing device for geotechnical exploration engineering and a rock ground stress test are disclosed, wherein a drilling machine is used for forming a drilling hole at an appointed position of surrounding rock, a plurality of stress sensing assemblies are formed outside the drilling hole, the stress sensing assemblies are pushed into the drilling hole by a push rod to an appointed depth, and grouting is performed on the upper space of an arched cement base of the stress sensing assemblies by a grouting rod, so that mortar on a detection surface of each stress sensing assembly is solidified under the pressure of the soft rock; and determining the ground stress of the stress sensing assembly based on the reading of the sensor of the stress sensing assembly, thereby establishing a soft rock region space mechanical model. The invention expands the initial ground stress field of the whole engineering range through the field measurement information, is more significant for guiding ground stress actual measurement and engineering construction, and has important practical value.)

1. An exploration engineering soft rock ground stress testing device comprises: a drilling machine for forming a drill hole in a surrounding rock body of the soft rock roadway; the stress sensing assembly comprises a pair of three-way pressure sensing boxes which are adjacently arranged and used for being arranged in the drill hole and detecting the ground stress in the drill hole; a push rod for pushing the stress sensing assembly to a specified depth within the borehole; a grout rod for grouting the borehole to fill the borehole; the standard cement columns are used for filling the space between the stress sensing assemblies, are made of cement mortar, have the same cross section as the area of the drilled hole and have different lengths; the stress sensing assembly comprises an arched cement base prepared from cement mortar, the lower surface of the arched cement base is an arched cambered surface, and the upper surface of the arched cement base is a plane; the three-way pressure sensor box is fixed in the arched cement base by cement mortar, and the part of the three-way pressure sensor box in the arched cement base is a conical body; the lowest point of the three detection surfaces of the three-way pressure sensing box in the horizontal height is higher than the upper surface of the arched cement base, so that the three detection surfaces are positioned above the arched cement base; the push rod is not provided with an angle measuring device.

2. The survey engineering soft rock ground stress test device of claim 1, characterized by: the bottom of the standard cement column is provided with a wire hole.

3. The survey engineering soft rock ground stress test device of claim 1, characterized by: the front end of the stress sensing component positioned at the deepest part of the drilled hole is not provided with a clamping tenon, and the rear end is provided with a clamping groove; the stress sensing component which is not positioned at the deepest part of the drill hole and the front end of the standard cement column are provided with tenons, and the rear end of the standard cement column is provided with corresponding clamping grooves; the cross-sectional shapes of the clamping grooves and the clamping tenons are trapezoidal.

4. The survey engineering soft rock ground stress test device of claim 1, characterized by: the front end of the push rod is provided with a clamping tenon corresponding to the clamping groove and used for pushing the stress sensing assembly and the standard cement column to a specified position in the drill hole.

5. A soft rock geostress test using the survey engineering soft rock geostress test device of claims 1-4, comprising: forming a drill hole at an appointed position of surrounding rock through a drilling machine, forming a plurality of stress sensing assemblies outside the drill hole, pushing the stress sensing assemblies into the drill hole by an appointed depth through a push rod, and grouting the space above an arched cement base of the stress sensing assemblies through a grouting rod, so that mortar on a detection surface of each stress sensing assembly is solidified under the pressure of soft rock; determining the length and the number of standard cement columns arranged between the stress sensing assemblies according to the distance between the stress sensing assemblies, and pushing the standard cement columns into the rotary holes, wherein the standard cement columns are meshed with the stress sensing assemblies through tenons and clamping grooves; sequentially pushing the stress sensing assemblies and the standard cement columns into the drill hole until all the stress sensing assemblies are arranged in the drill hole; determining the angle of the stress sensing assembly in the drill hole according to the angle of the stress sensing assembly at the rearmost end of the drill hole, wherein the angle of each stress sensing assembly can be determined according to the position angles of the tenon and the slot due to the meshing arrangement of each element in the drill hole; and determining the ground stress of the stress sensing assembly based on the reading of the sensor of the stress sensing assembly, thereby establishing a soft rock region space mechanical model.

Technical Field

The invention relates to the technical field of geotechnical exploration and measurement, in particular to a soft rock ground stress testing device for geotechnical exploration engineering.

Background

The stability of underground caverns and surrounding rocks thereof under complex conditions has been concerned, especially high ground stress, underground water development and relatively broken surrounding rocks, are very serious in deformation and damage and long in duration, and simultaneously show various characteristics such as unevenness and asymmetry in time and space, and the difficulty in excavation, support and maintenance is large.

The ground stress is the fundamental source of the pressure generation of the surrounding rock of the underground engineering. Gravity and constructional movements are the main causes of ground stress, with the constructional movements in the horizontal direction having the greatest influence on the formation of ground stress and its characteristics. The reason for forming the tectonic stress field is complex, so the distribution of the ground stress in the space is extremely uneven, and the statistical analysis of the distribution rule of the ground stress field in China finds that the distribution rule of the ground stress field in a small range area is more significant for guiding the ground stress actual measurement and the engineering construction.

Due to the complexity of constructing a stress field, the field measurement of the ground stress is the best means for accurately obtaining the initial ground stress at present, but due to the limitations of field conditions and testing techniques, the testing result often has great discreteness and even generates wrong data. Therefore, it is important to judge the rationality of the test result by using the statistical regional ground stress distribution rule. The method for researching the initial ground stress field of the whole engineering range based on limited field measurement information has important practical value.

At present, the traditional ground stress test methods such as a hydraulic fracturing method, an atomic magnetic resonance method, a pressure-volume method and the like are difficult to adapt to the requirements of stability analysis and safety monitoring of deep soft rock engineering, and a more effective ground stress test method is urgently needed in the underground engineering. In the prior art, the institute of martial-Chinese geotechnical mechanics of the Chinese academy of sciences proposes a mode of installing a pair of three-dimensional pressure sensing boxes in surrounding rock drilling to obtain the ground stress at a test point, thereby determining the ground stress distribution of soft rock and carrying out stability analysis. However, during the setting process of the three-way pressure sensing box, relative displacement may occur, which affects the accuracy of measurement; meanwhile, full-hole grouting needs to be carried out on the drilled hole when the three-way pressure sensing box is fixed.

In order to solve the problems, the invention patent of 201310496898.1 of Wuhan university provides a soft rock multi-point ground stress test method adopting a sensing column, and a three-way pressure sensing box is fixed in the sensing column in advance, and the sensing column is arranged in a drill hole for detection, so that the relative displacement of the three-way pressure sensing box is avoided, and the grouting amount is reduced. However, in the technical scheme, the sensing column is cemented outside the drill hole by cement mortar, and the self-stress of the sensing column is different from the cementing condition of the sensing column under the surrounding rock pressure in the drill hole, so that the measuring result is influenced; meanwhile, the sensing columns are easy to twist in the setting process, an angle measuring device needs to be arranged on a push rod used for moving the sensing columns, and when each sensing column is fixed, the final angle of the sensing column needs to be determined by the angle measuring device.

Disclosure of Invention

The invention provides a soft rock ground stress testing device for geotechnical exploration engineering, which is an improvement of the invention patent of 201310496898.1 and can solve the existing problems.

As one aspect of the invention, the invention provides a soft rock ground stress testing device for exploration engineering, which comprises: a drilling machine for forming a drill hole in a surrounding rock body of the soft rock roadway; the stress sensing assembly comprises a pair of three-way pressure sensing boxes which are adjacently arranged and used for being arranged in the drill hole and detecting the ground stress in the drill hole; a push rod for pushing the stress sensing assembly to a specified depth within the borehole; a grout rod for grouting the borehole to fill the borehole; the stress sensing assembly comprises an arched cement base prepared from cement mortar, the lower surface of the arched cement base is an arched cambered surface, and the upper surface of the arched cement base is a plane; the three-way pressure sensor box is fixed in the arched cement base by cement mortar, and the part of the three-way pressure sensor box in the arched cement base is a conical body; the lowest point of the three detection surfaces of the three-way pressure sensing box in the horizontal height is higher than the upper surface of the arched cement base, so that the three detection surfaces are positioned above the arched cement base.

Preferably, after each stress sensing assembly is arranged in the drill hole, the grouting rod grouts the arched cement base, so that grouting on the three detection surfaces of the three-way pressure sensing box is solidified under the pressure of soft rock.

Preferably, the normals of any two working faces of the pair of three-way pressure sensing boxes are not coincident.

Preferably, the lowest horizontal point of the three-way pressure sensing box is positioned on the section of the middle shaft of the arched cement base.

Preferably, the stress sensing assembly further comprises: a cylindrical front end made of cement and located in front of the three-way pressure sensing box; a cylindrical rear end made of cement located behind the three-way pressure sensing box; the diameter of the cylindrical rear end is 0.5-1 cm smaller than the diameter of the drill hole.

Preferably, the lower surface of the arched cement base is provided with a line hole for accommodating a data line.

As another aspect of the invention, an exploration engineering soft rock ground stress testing device is provided, which comprises: a drilling machine for forming a drill hole in a surrounding rock body of the soft rock roadway; the stress sensing assembly comprises a pair of three-way pressure sensing boxes which are adjacently arranged and used for being arranged in the drill hole and detecting the ground stress in the drill hole; a push rod for pushing the stress sensing assembly to a specified depth within the borehole; a grout rod for grouting the borehole to fill the borehole; the standard cement columns are used for filling the space between the stress sensing assemblies, are made of cement mortar, have the same cross section as the area of the drilled hole and have different lengths; the stress sensing assembly comprises an arched cement base prepared from cement mortar, the lower surface of the arched cement base is an arched cambered surface, and the upper surface of the arched cement base is a plane; the three-way pressure sensor box is fixed in the arched cement base by cement mortar, and the part of the three-way pressure sensor box in the arched cement base is a conical body; the lowest point of the three detection surfaces of the three-way pressure sensing box in the horizontal height is higher than the upper surface of the arched cement base, so that the three detection surfaces are positioned above the arched cement base; the push rod is not provided with an angle measuring device.

Preferably, the bottom of the standard cement column is provided with a line hole.

Preferably, the front end of the stress sensing component positioned at the deepest part of the drill hole is not provided with a clamping tenon, and the rear end is provided with a clamping groove; the stress sensing component which is not positioned at the deepest part of the drill hole and the front end of the standard cement column are provided with tenons, and the rear end of the standard cement column is provided with corresponding clamping grooves; the cross-sectional shapes of the clamping grooves and the clamping tenons are trapezoidal.

Preferably, the front end of the push rod is provided with a clamping tenon corresponding to the clamping groove and used for pushing the stress sensing assembly and the standard cement column to the designated position in the drill hole.

Preferably, when the stress sensing assemblies are arranged in the drill hole, the length and the number of the standard cement columns arranged between the adjacent stress sensing assemblies are determined according to the distance between the adjacent stress sensing assemblies in the depth direction, so that no gap exists between the adjacent stress sensing assemblies in the drill hole; the clamping tenon of the deepest standard cement column between the adjacent stress sensing assemblies is meshed with the clamping groove of the stress sensing assembly positioned at the front end of the clamping tenon, and the clamping groove of the shallowest standard cement column is meshed with the clamping tenon of the stress sensing assembly positioned at the rear end of the clamping tenon; and after setting all the stress sensing assemblies in the drill hole, determining the angle of the stress sensing assembly in the drill hole according to the angle of the stress sensing assembly positioned at the rearmost end of the drill hole.

Drawings

Fig. 1 is a schematic structural diagram of a stress sensing assembly according to an embodiment of the invention.

FIG. 2 is a schematic view of a stress sensing assembly and a standard cement column according to a preferred embodiment of the present invention.

Detailed Description

In order to more clearly illustrate the technical solutions of the present invention, the present invention will be briefly described below by using embodiments, and it is obvious that the following description is only one embodiment of the present invention, and for those skilled in the art, other technical solutions can be obtained according to the embodiments without inventive labor, and also fall within the disclosure of the present invention.

The soft rock ground stress testing device for exploration engineering comprises a drilling machine, a stress sensing assembly, a push rod and a grouting rod. The drilling machine is used for forming drill holes with set depth at a plurality of designated positions in the surrounding rock body according to exploration requirements.

And the stress sensing assembly is used for being arranged in the drill hole and detecting the ground stress in the drill hole. Multiple stress sensing assemblies can be disposed at different depths within a borehole.

And the push rod is used for pushing the stress sensing assembly to a specified depth in the drill hole. A grouter bar for grouting the borehole to fill the borehole. An angle sensing device can be arranged on the push rod, so that the final angle of the stress sensing assembly can be determined according to the angle change of the push rod.

The structure of the stress sensing assembly is shown in fig. 1, and comprises an arched cement base 10 made of cement mortar, a cylindrical front end 20, a cylindrical rear end 30, a three-way pressure sensing box 40 and a three-way pressure sensing box 50 which are adjacently arranged.

The three-way pressure sensing box 40 and the three-way pressure sensing box 50 are placed in the cement mortar mold outside the borehole to form a stress sensing assembly. Wherein, the normal lines of any two working surfaces of the three-way pressure sensing boxes 40 and 50 are not coincident. A three-way pressure sensing cartridge known in the art may be used.

The lower surface 11 of the arched cement base 10 is an arched cambered surface, and the upper surface 12 is a plane. A wire hole may be provided at the lower end of the lower surface 11 of the arched cement base 10 for the arrangement of the sensor data wire. The three-way pressure sensing box 40 and the three-way pressure sensing box 50 are fixed in the arched cement base 10 by cement mortar. The three-way pressure sensing box 40 and the three-way pressure sensing box 50 are arranged as follows: the three-way pressure sensing box 40 and the three-way pressure sensing box 50 are made into conical bodies in the arched cement base 10; the lowest point in the horizontal height of the three detection surfaces 401, 402, 403 of the three-way pressure sensing capsule 40 and the three detection surfaces 501, 502, 503 of the three-way pressure sensing capsule 50 is higher than the upper surface 12 of the arcuate cement base 10, so that the three detection surfaces 401, 402, 403 of the three-way pressure sensing capsule 40 and the three detection surfaces 501, 502, 503 of the three-way pressure sensing capsule 50 are located above the arcuate cement base 10. After the space above the arched cement base 10 is placed at a position with a specified depth of the drilled hole by the stress sensing assembly, cement mortar is injected into the space by the grouting rod, so that the mortar above the detection surfaces of the three-way pressure sensing boxes 40 and 50 is solidified under the condition of being subjected to the pressure of soft rock, and meanwhile, the space between the stress sensing assembly and the surrounding rock body is filled.

The cylindrical front end 20 is made of cement and is located in front of the three-way pressure sensing boxes 40 and 50; a cylindrical rear end made of cement, located behind the three-way pressure sensing boxes 40 and 50; the diameters of the cylindrical front end 40 and the cylindrical rear end 50 are 0.5 to 1cm smaller than the diameter of the drilled hole.

Through the arrangement of the soft rock ground stress testing device in the embodiment of the invention, cement mortar in a drill hole above the sensing surface of the three-way pressure sensing box in the stress sensing assembly is cemented under the pressure of surrounding rocks, so that the measuring result is not influenced; meanwhile, the stress sensing assembly is formed outside the drill hole, so that the grouting amount of the drill hole can be reduced.

In the embodiment, the stress sensing assembly is easy to twist in the setting process, so that the push rod for pushing the sensing columns needs to be provided with an angle measuring device, and the final angle of each sensing column is determined; meanwhile, the space between the adjacent drilling hole stress sensing assemblies needs grouting, and the sensor data line in the drilling hole is possibly affected in the cement mortar solidification process, so that the sensor data line is damaged and the measurement cannot be realized.

The device for testing the ground stress of the soft rock in the exploration engineering comprises a drilling machine, a stress sensing assembly, a plurality of standard cement columns, a push rod and a grouting rod. The drilling machine is used for forming drill holes with set depth at a plurality of designated positions in the surrounding rock body according to exploration requirements.

And the stress sensing assembly is used for being arranged in the drill hole and detecting the ground stress in the drill hole. Multiple stress sensing assemblies can be disposed at different depths within a borehole.

Structure of stress sensing assembly referring to fig. 2, unlike the first embodiment, the stress sensing assembly 100 located at the deepest part of the drilled hole has no tenon at the front end and a slot 110 at the rear end; the stress sensing component 200, which is not located at the deepest part of the borehole, has a tenon 220 at the front end and a corresponding slot 210 at the rear end.

The standard cement column comprises a plurality of standard cement columns with different lengths, which are made of cement mortar, have the same section as the area of the drilled hole and have different lengths. The bottom of the standard cement column is provided with a wire hole for arranging a data wire. The front end of the standard cement column is provided with a clamping tenon, and the rear end of the standard cement column is provided with a corresponding clamping groove.

The standard cement column is used for filling the space between the stress sensing assemblies, and the specification of the standard cement column arranged between the stress sensing assemblies can be determined according to the distance between the stress sensing assemblies in the drill hole. For example, in FIG. 2, standard cement columns 300 and 400 of different lengths may be provided between the stress sensing assembly 100 and the stress sensing assembly 200.

And the push rod is used for pushing the stress sensing assembly to a specified depth in the drill hole. A grouter bar for grouting the borehole to fill the borehole. Wherein, the push rod is not provided with an angle sensing device.

When the soft rock ground stress testing device of the embodiment is used for testing, a drilling hole is formed at the appointed position of surrounding rock through a drilling machine, a plurality of stress sensing assemblies are formed outside the drilling hole, the stress sensing assemblies are pushed into the drilling hole by a push rod to the appointed depth, and grouting is performed on the upper space of the arched cement base of the stress sensing assemblies through a grouting rod, so that mortar on the detection surface of the stress sensing assemblies is solidified under the pressure of the soft rock; determining the length and the number of standard cement columns arranged between the stress sensing assemblies according to the distance between the stress sensing assemblies, and pushing the standard cement columns into the rotary holes, wherein the standard cement columns are meshed with the stress sensing assemblies through tenons and clamping grooves; sequentially pushing the stress sensing assemblies and the standard cement columns into the drill hole until all the stress sensing assemblies are arranged in the drill hole; determining the angle of the stress sensing assembly in the drill hole according to the angle of the stress sensing assembly at the rearmost end of the drill hole, wherein the angle of each stress sensing assembly can be determined according to the position angles of the tenon and the slot due to the meshing arrangement of each element in the drill hole; and determining the ground stress of the stress sensing assembly based on the reading of the sensor of the stress sensing assembly, thereby establishing a soft rock region space mechanical model.

With the above preferred embodiment of the invention, the angles of all stress sensors can be determined by the angle of the stress sensor assembly at the rearmost end of the borehole without recording the angle of each stress sensor assembly; while avoiding damage to the data lines.

All documents referred to herein are incorporated by reference into this application as if each were individually incorporated by reference. The above description is only for the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. The particular features, structures, materials, or characteristics described in this disclosure may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention shall fall within the protection scope of the present invention.