Method for comprehensive evaluation of dynamic and static performance of anchor cable

Abstract

The application provides a kind of anchor cable dynamic-statics performance comprehensive evaluation method, belongs to underground engineering technical field.The anchor cable dynamic-statics performance comprehensive evaluation method includes: by anchor cable performance testing device to the anchor cable to be evaluated to apply prestress value F P , test obtains the total elongation of the anchor cable to be evaluated η I , elastic deformation d I And energy absorption rate e I ;Preparation rock mass simulation material, to make the joint support structure to be evaluated, by anchor cable performance testing device to the joint support structure to be evaluated to apply prestress value F P , test obtains the total elongation of the anchor cable to be evaluated η Ⅱ , elastic deformation d Ⅱ And energy absorption rate e Ⅱ ;Calculate the comprehensive performance evaluation parameter K of the anchor cable to be evaluated.The anchor cable dynamic-statics performance comprehensive evaluation method can accurately measure the actual data of the anchor cable to be evaluated under dynamic-static coupling state, and comprehensively evaluate the comprehensive performance of the anchor cable to be evaluated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of underground engineering, in particular to a method for comprehensively evaluating dynamic and static performance of anchor cable. BACKGROUND

[0002] In recent years, with the rapid development of national economy, the state pays more and more attention to the development and utilization of underground space, and the field of underground engineering has achieved unprecedented development. In the process of underground engineering construction, anchor cable and anchor cable-protection net combined support system is a commonly used support method, and the performance of anchor cable is directly related to the safety of underground engineering construction.

[0003] At present, the existing anchor cable performance testing device can only measure the static or dynamic performance of anchor cable. In actual engineering, anchor cable is often in a dynamic-static coupling state. The existing test method is difficult to simulate the stress environment of anchor cable in actual engineering, and there is a lack of comprehensive performance testing method for anchor cable-protection net combined support system, so the comprehensive performance of anchor cable in dynamic-static coupling state cannot be accurately measured, and there is a lack of method for comprehensively evaluating the comprehensive performance of anchor cable. SUMMARY

[0004] The purpose of the present application is to provide a method for comprehensively evaluating dynamic and static performance of anchor cable, which can accurately measure the actual data of the anchor cable under evaluation in dynamic-static coupling state, comprehensively evaluate the comprehensive performance of the anchor cable under evaluation, and thus provide guidance for anchor cable support design in underground engineering.

[0005] To achieve the purpose of the present application, the following technical solutions are adopted:

[0006] According to one aspect of the present application, a method for comprehensively evaluating dynamic and static performance of anchor cable is provided, which comprises the following steps: performing dynamic-static coupling test of anchor cable on the anchor cable under evaluation by anchor cable performance testing device, and performing dynamic-static coupling test of precast combined support structure on the precast combined support structure, and obtaining comprehensive evaluation method combined with test results, wherein the method for comprehensively evaluating dynamic and static performance of anchor cable comprises the following steps: the anchor cable mechanical property testing device can stretch the anchor cable by the lower oil cylinder to apply pre-stress, while releasing the anchor cable from the upper drop hammer impact, so as to realize dynamic-static coupling stress state of the anchor cable; applying pre-stress value F P to the anchor cable under evaluation by the anchor cable mechanical property testing device to perform dynamic-static coupling test, and obtaining total elongation η I , elastic deformation d I and energy absorption rate e I of the anchor cable under evaluation; precasting rock mass simulation material, precasting the rock mass simulation material, the anchor cable under evaluation and the net into the evaluated combined support structure, and applying pre-stress value F P, anchor cable anchor net dynamic impact test, the total elongation of the anchor cable in the evaluation of the joint support structure η II , elastic deformation d II and energy absorption rate e II ; according to the test results of anchor cable and prefabricated joint support structure, the comprehensive performance evaluation parameter K of the anchor cable is calculated.

[0007] According to an embodiment of the application, wherein the comprehensive performance evaluation parameter K corresponds to the formula: , wherein α, β, γ are equivalent transformation parameters, and θ is the energy reduction coefficient.

[0008] According to an embodiment of the application, wherein the anchor cable performance testing device comprises a first support, a first hydraulic loading cylinder, a first electromagnetic lock, a first drop hammer and a first laser range finder, the first hydraulic loading cylinder is connected to the bottom of the first support, the top end of the anchor cable under evaluation is connected to the first support, the bottom end of the anchor cable under evaluation is connected to the first hydraulic loading cylinder, so as to apply static load to the anchor cable under evaluation through the first hydraulic loading cylinder, the first electromagnetic lock is connected to the top of the first support, the first drop hammer is magnetically connected to the first electromagnetic lock, so as to apply dynamic load to the anchor cable under evaluation, and the first laser range finder is arranged on the top of the first support to obtain the test data of the anchor cable under evaluation.

[0009] According to an embodiment of the application, wherein the anchor cable mechanical property testing device applies a prestress value F P-I to the anchor cable under evaluation on site, performs anchor cable dynamic-static coupling test, and obtains the total elongation η I , elastic deformation d I and energy absorption rate e I of the anchor cable under evaluation, comprising: cutting a length L of the anchor cable under evaluation to pass through the limiting hole on the top of the first support, the top end of the anchor cable under evaluation is fixed to the first support through a lock, and the bottom end of the anchor cable under evaluation is fixed to the first hydraulic loading cylinder through the lock; a prestress value F P-I is applied to the anchor cable under evaluation through the first hydraulic loading cylinder, and the anchor cable under evaluation is stabilized for a period of time; the height of the first drop hammer to the bottom end of the anchor cable under evaluation is set to h according to the test requirements, so as to release the impact energy E I of the first drop hammer to the anchor cable under evaluation through the first electromagnetic lock, and the maximum deformation d L of the anchor cable under evaluation in this impact is recorded by using the first laser range finder; the prestress value F P-I is applied to the anchor cable under evaluation through the first hydraulic loading cylinder, and the impact energy E IThe first laser range finder is used to record the maximum deformation d of the anchor cable in the impact L , until the anchor cable breaks, and the maximum stretching D of the anchor cable is obtained by the first laser range finder T-I .

[0010] According to an embodiment of the present application, the anchor cable performance testing device further comprises a second support, a tray, a second electromagnetic lock, a second drop hammer, a second hydraulic loading cylinder, a second laser range finder and a stress monitor. The tray is arranged at the bottom of the second support, the joint support structure under test is arranged on the tray, the second electromagnetic lock is connected to the top of the second support, the second drop hammer is magnetically connected with the second electromagnetic lock, so that the second drop hammer applies a dynamic load to the joint support structure under test, the second hydraulic loading cylinder is connected to the top of the first support, the output end of the second hydraulic loading cylinder is provided with a loading plate, the loading plate abuts against the top surface of the joint support structure under test, so as to apply a static load to the joint support structure under test, and the second laser range finder and the stress monitor are arranged at the top of the second support, respectively, to obtain test data of the joint support structure under test.

[0011] According to an embodiment of the present application, the rock mass simulation material, the anchor cable under test and the anchor net are made into a joint support structure under test, the anchor cable performance testing device is used to apply a pre-stress value F P to the joint support structure under test according to the field, a dynamic impact test of the anchor cable and the anchor net is performed, and the total elongation η II , the elastic deformation d II and the energy absorption rate e II of the anchor cable under test in the joint support structure under test are obtained. The rock mass simulation material is prefabricated according to actual rock mass mechanical parameters in the field, the rock mass simulation material is drilled and the anchor cable under test is placed in the rock mass simulation material according to the spacing between the anchor cables in the field, the anchor net is arranged below the rock mass simulation material and is fixedly connected with the anchor cable under test and the rock mass simulation material to form an integral whole, the top of the anchor cable under test is fixed to the top of the second support through a lock, and the rock mass simulation material is fixed to the tray through the lock; the second hydraulic loading cylinder and the loading plate abut against the joint support structure under test, a pre-stress value F P is applied to the anchor cable under test, the height h of the second drop hammer to the top end of the joint support structure under test is set according to test requirements, so that the second drop hammer generates an impact load with impact energy E II to the joint support structure under test through the second electromagnetic lock, and the second laser range finder is used to record the maximum deformation d L; repeat the previous step until the anchor cable under test breaks, and obtain the total extension length D of the anchor cable under test by the second laser range finder T-II .

[0012] According to an embodiment of the present application, wherein the energy absorption rate e I and the energy absorption rate e II is: 、 , wherein E T is the total energy generated by the drop hammer in the total test process, D T-I and D T-II is the total extension length of the anchor cable from the original length until it breaks.

[0013] According to an embodiment of the present application, wherein the total extension rate η I and the total extension rate η II is: 、 , wherein L is the original length of the anchor cable.

[0014] According to an embodiment of the present application, wherein the elastic deformation d I and the elastic deformation d II is: 、 , wherein d L is the maximum deformation of the anchor cable under each impact.

[0015] An embodiment of the present application has the following advantages or beneficial effects:

[0016] The anchor cable dynamic-statics performance comprehensive evaluation method can accurately measure the actual data of the anchor cable under test in the dynamic-static coupling state, accurately and effectively reflect the impact resistance of the anchor cable in the underground engineering or the impact resistance of the combined support structure composed of the anchor cable-anchor net, and provide important parameter basis for the roadway support design; the comprehensive performance of the anchor cable is comprehensively evaluated by combining the performance of the anchor cable itself with the performance of the combined support structure, a multi-angle comprehensive evaluation model is established, and important basis is provided for the performance evaluation of the roadway surrounding rock support. BRIEF DESCRIPTION OF DRAWINGS

[0017] The above and other features and advantages of the present application will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings.

[0018] Figure 1 is a schematic diagram of an anchor cable dynamic-statics performance comprehensive evaluation method according to an exemplary embodiment.

[0019] Figure 2is a structural schematic diagram of a dynamic-static coupling test of an anchor cable using an anchor cable performance test device according to an exemplary embodiment.

[0020] Figure 3 is a structural schematic diagram of a dynamic-static coupling test of a prefabricated combined support structure using an anchor cable performance test device according to an exemplary embodiment.

[0021] In the drawings, the reference numerals:

[0022] 1, anchor cable under evaluation; 2, rock mass simulation material; 3, anchor net; 4, first support; 5, first hydraulic loading oil cylinder; 6, first electromagnetic lock; 7, first drop hammer; 8, second support; 9, tray; 10, second electromagnetic lock; 11, second drop hammer; 12, second hydraulic loading oil cylinder; 13, loading plate; 14, lock. DETAILED DESCRIPTION

[0023] Example embodiments now will be described more fully hereinafter with reference to the accompanying drawings; however, these embodiments can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the example embodiments to those skilled in the art. Like reference numerals refer to like elements throughout the figures, and thus description of the same will be simplified or omitted.

[0024] The use of the terms "one," "a," "the" and "said" to describe the various embodiments is intended to indicate that there are one or more of the items. The use of the terms "includes" and "including" is intended to be open-ended and mean that there can be additional items that are not listed.

[0025] As Figures 1 to 3 shown, Figure 1 A schematic diagram of a dynamic-static mechanical performance comprehensive evaluation method provided by the present application is shown. Figure 2 A structural schematic diagram of a dynamic-static coupling test of an anchor cable using an anchor cable performance test device according to an exemplary embodiment is shown. Figure 3 A structural schematic diagram of a dynamic-static coupling test of a prefabricated combined support structure using an anchor cable performance test device according to an exemplary embodiment is shown.

[0026] This invention provides a method for comprehensively evaluating the dynamic and static performance of anchor cables. The method involves conducting dynamic-static coupling tests on the anchor cable under evaluation (1) using an anchor cable performance testing device, and also conducting dynamic-static coupling tests on the prefabricated combined support structure. The comprehensive evaluation method is derived by combining the test results. The method is characterized by the following features: the anchor cable mechanical performance testing device can apply prestress to the anchor cable by statically tensile testing it with a lower hydraulic cylinder, while simultaneously releasing an upper drop hammer to impact the anchor cable, achieving a dynamic-static coupling stress state; and applying a prestress value F to the anchor cable under evaluation (1) using the anchor cable mechanical performance testing device. P An anchor cable dynamic-static coupling test was conducted to obtain the total elongation η of the evaluated anchor cable 1. I Elastic deformation d I and energy absorption rate e I ;

[0027] Precast rock mass simulation material 2, along with the evaluated anchor cable 1 and anchor mesh 3, are precast into the evaluated combined support structure. A prestress value F is applied to the evaluated combined support structure using an anchor cable mechanical performance testing device. P Dynamic impact tests were conducted on anchor cables and anchor nets to obtain the total elongation η of the evaluated anchor cable 1 in the evaluated combined support structure. Ⅱ Elastic deformation d Ⅱ and energy absorption rate e Ⅱ The comprehensive performance evaluation parameter K of the anchor cable 1 under evaluation is calculated based on the test results of the anchor cable and the prefabricated combined support structure.

[0028] like Figures 1 to 3 As shown, the first step is to determine the required prestress value F for the anchor cable 1 under evaluation based on the rock mass simulation material 2 or other actual conditions. P After connecting the anchor cable 1 to the impact device of the anchor mesh 3, the prestress value F is applied to the anchor cable 1 through the first hydraulic loading cylinder 5. P Subsequently, a dynamic-static coupling test of the anchor cable was conducted, and an impact energy E was generated on the evaluated anchor cable 1 according to the test requirements. I During the dynamic-static coupling test of the anchor cable, the impact load was repeatedly applied to the anchor cable under evaluation until it broke. The deformation of the anchor cable under evaluation was measured using a first laser rangefinder to obtain the total extension length D of the anchor cable under evaluation. T-I; second step, reselect at least three anchor cables 1, preferably four anchor cables 1 are selected, the rock mass simulation material 2 is obtained from the field, the rock mass simulation material 2 is drilled and placed in the anchor cable 1 according to the anchor cable spacing of the field, an anchor net 3 is placed below the rock mass simulation material 2, the anchor cable 1, the anchor net 3 and the rock mass simulation material 2 are fixed into an integral to make the evaluated combined support structure, then the impact pad is installed on the top surface of the rock mass simulation material 2, which can play a buffering role, prevent the rock mass simulation material 2 from moving downwards by a large amplitude to produce a large impact on the anchor net 3, then the evaluated combined support structure is connected to the anchor cable mechanical property testing device, the pre-stress value F P of the evaluated anchor cable 1 is applied by the second hydraulic loading oil cylinder 12 I After that, the anchor cable dynamic-static coupling test is carried out, the impact load of the impact energy E T-II of the evaluated anchor cable 1 is generated according to the test requirements, the impact load is repeatedly applied to the evaluated anchor cable 1 during the anchor cable dynamic-static coupling test until the evaluated anchor cable 1 is broken, the deformation of the four evaluated anchor cables 1 is measured by the second laser range finder to obtain the average total elongation D I of the four evaluated anchor cables 1 I ; third step, the comprehensive performance evaluation parameter K of the evaluated anchor cable 1 is calculated through various test data obtained by the anchor cable dynamic-static coupling test and the data on the scene, the actual data of the evaluated anchor cable 1 in the dynamic-static coupling state can be accurately measured through the method, and the impact resistance of the anchor cable in the underground engineering or the impact resistance of the combined support structure composed of the anchor cable-anchor net can be accurately and effectively reflected, thereby providing important parameter basis for roadway support design.

[0029] In a preferred embodiment of the application, the formula corresponding to the comprehensive performance evaluation parameter K is: Wherein, α, β, γ are equivalent transformation parameters, and θ is an energy reduction coefficient.

[0030] As shown in Figure 1 , the value of the comprehensive performance evaluation parameter K is influenced by the total elongation rate η I , the elastic deformation d I and the energy absorption rate e I of the evaluated anchor cable 1, and the total elongation rate η II , the elastic deformation d II and the energy absorption rate e II of the evaluated anchor cable 1 in the evaluated combined support structure, the comprehensive performance of the anchor cable can be comprehensively evaluated by combining the performance of the anchor cable itself and the performance of the combined support structure, a multi-angle comprehensive evaluation model is established, and important basis is provided for the support performance evaluation of the surrounding rock of the roadway. The calculation formula of the elastic deformation d I and the elastic deformation d II is: , Wherein, d L is the maximum deformation of the anchor cable each time.

[0031] In a preferred embodiment of the present application, the anchor cable performance testing device comprises a first support 4, a first hydraulic loading oil cylinder 5, a first electromagnetic lock 6, a first drop hammer 7 and a first laser range finder, the first hydraulic loading oil cylinder 5 is connected to the bottom of the first support 4, the top end of the anchor cable 1 under test is connected to the first support 4, and the bottom end of the anchor cable 1 under test is connected to the first hydraulic loading oil cylinder 5 to apply static load to the anchor cable 1 under test through the first hydraulic loading oil cylinder 5, the first electromagnetic lock 6 is connected to the top of the first support 4, and the first drop hammer 7 is magnetically connected to the first electromagnetic lock 6 to apply dynamic load to the anchor cable 1 under test, and the first laser range finder is arranged at the top of the first support 4 to obtain test data of the anchor cable 1 under test.

[0032] As shown in Figure 2 , the cylinder body of the first hydraulic loading oil cylinder 5 is fixed to the lower part of the first support 4, and the first electromagnetic lock 6 is fixed to the upper part of the first support 4, when testing is required, the lower end of the anchor cable 1 under test is fixed with the cylinder rod of the first hydraulic loading oil cylinder 5, so that the anchor cable 1 under test can be pre-stressed by the first hydraulic loading oil cylinder 5, the upper end of the anchor cable 1 under test passes through the first drop hammer 7 and the first electromagnetic lock 6 in turn and is fixed on the top of the first support 4 by the lock 14, the first electromagnetic lock 6 is energized to be magnetically attracted to the first drop hammer 7, so that the first drop hammer 7 is lifted to a predetermined height and fixed with the first electromagnetic lock 6, and after the first electromagnetic lock 6 is de-energized during testing, the first drop hammer 7 is released, and the first drop hammer 7 falls along the anchor cable 1 under test, thereby applying dynamic load to the lower end of the anchor cable 1 under test, and the first laser range finder is arranged at the top of the first support 4, so that the irradiation direction of the laser is parallel to the anchor cable 1 under test, thereby more accurately measuring the stretching amount of the anchor cable 1 under test during the application of dynamic load and static load.

[0033] In a preferred embodiment of the present application, the anchor cable mechanical property testing device applies a pre-stress value F P-I to the anchor cable 1 under test according to the site, performs dynamic-static coupling test of the anchor cable 1 under test, and obtains total elongation η I , elastic deformation d I and energy absorption rate e I of the anchor cable 1 under test, which comprises: cutting a length L of the anchor cable 1 under test to pass through the limiting hole at the top of the first support 4, the top end of the anchor cable 1 under test is fixed to the first support 4 by the lock 14, and the bottom end of the anchor cable 1 under test is fixed to the first hydraulic loading oil cylinder 5 by the lock 14; applying a pre-stress value F P-I to the anchor cable 1 under test by the first hydraulic loading oil cylinder 5 and stabilizing the anchor cable 1 under test for a period of time;

[0034] The height of the first drop hammer 7 to the bottom end of the anchor cable 1 under test is set to h according to the test requirements, so as to release the impact energy E IThe maximum deformation d of the anchor cable in this impact is recorded by using the first laser range finder L The pre-stress value F of the anchor cable under test 1 is repeatedly applied by the first hydraulic loading cylinder 5 P-I The impact energy E of the first drop hammer 7 on the anchor cable under test 1 is released by the first electromagnetic lock 6 I The maximum deformation d of the anchor cable in this impact is recorded by using the first laser range finder L Until the anchor cable under test 1 is broken, and the maximum extension D of the anchor cable under test 1 is obtained by the first laser range finder T-I .

[0035] As shown in Figure 1 and Figure 2 , a section of the anchor cable under test 1 is cut off to adapt the length of the anchor cable under test 1 to the test length L of the anchor cable mechanical property testing device, the upper end of the anchor cable under test 1 is fixed to the first support 4 through the lock 14 after passing through the limiting hole at the top of the first support 4, and the lower end of the anchor cable under test 1 is fixed with the cylinder rod of the first hydraulic loading cylinder 5, so as to apply the pre-stress value F of the anchor cable under test 1 by the first hydraulic loading cylinder 5 P Then the height of the first electromagnetic lock 6 is adjusted, so that the height from the first drop hammer 7 fixed with the first electromagnetic lock 6 to the lower end of the anchor cable under test 1 is h, so that the impact energy E of the lower end of the anchor cable under test 1 is generated when the first drop hammer 7 falls I The impact load of the anchor cable under test 1 is E P The impact energy E of the first drop hammer 7 on the lower end of the anchor cable under test 1 is generated again after the first electromagnetic lock 6 is powered off I The impact load of the anchor cable under test 1 is E T-I .

[0036] In a preferred embodiment of the present invention, the anchor cable performance testing device further includes a second support 8, a tray 9, a second electromagnetic lock 10, a second drop hammer 11, a second hydraulic loading cylinder 12, a second laser rangefinder, and a stress monitor. The tray 9 is disposed at the bottom of the second support 8, and the combined support structure to be evaluated is disposed on the tray 9. The second electromagnetic lock 10 is connected to the top of the second support 8, and the second drop hammer 11 is magnetically connected to the second electromagnetic lock 10 so that the second drop hammer 11 applies dynamic load to the combined support structure to be evaluated. The second hydraulic loading cylinder 12 is connected to the top of the first support 4, and a loading plate 13 is disposed at the output end of the second hydraulic loading cylinder 12. The loading plate 13 abuts against the top surface of the combined support structure to apply static load to the combined support structure to be evaluated. The second laser rangefinder and the stress monitor are respectively disposed at the top of the second support 8 to obtain test data of the combined support structure to be evaluated.

[0037] like Figure 3 As shown, the anchor cable 1 in the evaluated joint support structure is fixed to the second support 8. The cylinder body of the second hydraulic loading cylinder 12 is fixed to the upper part of the second support 8. The cylinder rod of the second hydraulic loading cylinder 12 passes through the second electromagnetic lock 10 and the second drop hammer 11 from top to bottom and is fixed to the loading plate 13. The loading plate 13 abuts against the top surface of the rock mass simulation material 2 of the evaluated joint support structure. The lower part of the evaluated joint support structure is fixed to the tray 9 by a lock. In this way, the evaluated joint support structure can be fixed on the anchor cable mechanical performance testing device. Preferably, the impact pad abuts against the top surface of the rock mass simulation material 2 to prevent the rock mass simulation material 2 from moving down significantly and causing a large impact on the anchor mesh 3. Then, the second hydraulic loading cylinder... 12 and loading plate 13 apply prestress to the anchor cable 1 under evaluation. The second electromagnetic lock 10 is energized so that it is magnetically attracted to the second drop hammer 11, thereby raising the second drop hammer 11 to a predetermined height and fixing it to the second electromagnetic lock 10. During the test, the second electromagnetic lock 10 is de-energized and the second drop hammer 11 is released. The second drop hammer 11 falls along the anchor cable 1 under evaluation, thereby applying dynamic load to the rock mass simulation material 2, thereby indirectly applying dynamic load to the anchor cable 1 under evaluation. The stress monitoring instrument is set at the top of the second support 8, or it can be at other positions of the second support 8. The second laser rangefinder is set at the top of the second support 8 so that the laser irradiation direction is parallel to the anchor cable 1 under evaluation, thereby more accurately measuring the tensile amount generated by the anchor cable 1 under evaluation during the application of dynamic and static loads.

[0038] In a preferred embodiment of the present invention, the rock mass simulation material 2, the evaluated anchor cable 1, and the anchor mesh 3 are used to construct the evaluated combined support structure. A prestress value F is applied to the evaluated combined support structure using an anchor cable mechanical performance testing device based on the field conditions. P An anchor-net dynamic impact test was conducted to obtain the total elongation η of the evaluated anchor cable 1 in the evaluated combined support structure. Ⅱ Elastic deformation d Ⅱ and energy absorption rate eⅡ The process includes: prefabricating rock mass simulation material 2 according to the actual rock mechanics parameters on site; drilling holes in the rock mass simulation material 2 according to the spacing between anchor cables on site and inserting the anchor cables to be evaluated 1; setting the anchor mesh 3 below the rock mass simulation material 2 and fixing it together with the anchor cables to be evaluated 1 and the rock mass simulation material 2 as a whole; fixing the top of the anchor cables to be evaluated 1 to the top of the second support 8 with locking devices 14; fixing the rock mass simulation material 2 to the tray 9 with locking devices 14; and abutting the second hydraulic loading cylinder 12 and the loading plate 13 with the combined support structure to be evaluated, applying a prestress value F to the anchor cables to be evaluated 1. P According to the test requirements, the height of the second drop hammer 11 to the top of the evaluated combined support structure is set to h, so that the second drop hammer 11 can be released through the second electromagnetic lock 10 to generate impact energy E on the evaluated combined support structure. II The impact load was measured, and the maximum deformation d of the anchor cable during the impact was recorded using a second laser rangefinder. L Repeat the previous step until the evaluated anchor cable 1 breaks, and obtain the total extension length D of the evaluated anchor cable 1 using the second laser rangefinder. T-II .

[0039] like Figure 1 and Figure 3 As shown, rock mass simulation material 2 is prefabricated according to the actual rock mass mechanics parameters on site. Preferably, the rock mass simulation material 2 is obtained on site and prefabricated according to the actual rock mass mechanics parameters on site. Then, at least three anchor cables 1 are selected for evaluation, and four anchor cables 1 are preferred in this application. Holes are drilled into the rock mass simulation material 2 according to the spacing between the anchor cables on site. Anchor mesh 3 is set below the rock mass simulation material 2. After the anchor cables 1 are passed through the holes, the anchor cables 1, anchor mesh 3 and rock mass simulation material 2 are fixed into a whole by locking or other means. Then, the lower end of the anchor cable 1 is fixed to the tray 9, which can be fixed by locking. The upper end of the anchor cable 1 is fixed to the second bracket 8. The cylinder rod of the second hydraulic loading cylinder 12 drives the loading plate 13 to move down and abut against the rock mass simulation material 2 to apply prestress F to the evaluated combined support structure. P- Then, adjust the height of the second electromagnetic lock 10 so that the height of the second hammer 11 above the top surface of the evaluated combined support structure after it is fixed to the second electromagnetic lock 10 is h, so that the second hammer 11 will generate impact energy E on the evaluated combined support structure when it falls. II The impact load is applied, and then the second drop hammer 11 is reset and fixed to the second electromagnetic lock 10. Preferably, a reset button and a reset mechanism are provided on the second bracket 8. The reset button is operated so that the reset mechanism raises the second drop hammer 11 until it is fixed to the second electromagnetic lock 10. The second hydraulic loading cylinder 12 is then readjusted to apply a prestress value F to the evaluated combined support structure. P After the second electromagnetic lock 10 is de-energized, the second drop hammer 11 is released, which again generates impact energy E on the top surface of the evaluated combined support structure. IIThe impact load was applied repeatedly until the anchor cable 1 under evaluation broke. The total extension length D of the anchor cable 1 under evaluation was obtained by measuring with a second laser rangefinder. T-II Therefore, it can be done through the formula , Calculate the total elongation η I and total elongation η II Where L is the original length of the anchor cable. And through the formula... , E T D represents the total energy generated by the falling hammer during the entire test. T-I and D T-II It is the total extension length of the anchor cable from its original length until it breaks.

[0040] The comprehensive evaluation method for the dynamic and static performance of anchor cables of the present invention can accurately measure the actual data of the anchor cable 1 under dynamic-static coupling state, accurately and effectively reflect the impact resistance performance of anchor cables or the impact resistance performance of the combined support structure composed of anchor cables and anchor nets in underground engineering, and provide important parameter basis for roadway support design; combining the performance of the anchor cable itself and the performance of the combined support structure to comprehensively evaluate the overall performance of the anchor cable, and establish a multi-angle comprehensive evaluation model, which provides an important basis for the evaluation of the support performance of roadway surrounding rock.

[0041] In this embodiment of the invention, the term "multiple" refers to two or more, unless otherwise explicitly defined. The terms "install," "connect," and "fix" should be interpreted broadly. For example, "connect" can mean a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this embodiment of the invention based on the specific circumstances.

[0042] In the description of the embodiments of the present invention, it should be understood that the terms "upper" and "lower" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention.

[0043] In the description of this specification, the terms "an embodiment," "a preferred embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0044] The above merely describes the preferred embodiments of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for comprehensively evaluating the dynamic and static performance of an anchor cable, the method comprising the following steps: performing a dynamic-static coupling test on an anchor cable (1) to be evaluated by means of an anchor cable performance testing device, and performing a dynamic-static coupling test on a prefabricated combined support structure, and obtaining a comprehensive evaluation method in combination with the test results, characterized in that, The anchor cable dynamic-static mechanical property comprehensive evaluation method comprises: The anchor cable mechanical property testing device can perform static tension on the anchor cable through the lower oil cylinder, apply prestress, and release the upper drop hammer to impact the anchor cable, so as to realize the dynamic-static coupling stress state of the anchor cable; The anchor cable (1) to be evaluated is subjected to a prestress value F by an anchor cable mechanical property testing device P , a dynamic-static coupling test is performed, and total elongation η I , elastic deformation d I , and energy absorption rate e I of the anchor cable (1) to be evaluated are obtained A precast rock mass simulation material (2) is precast into a joint support structure to be evaluated together with the anchor cable (1) and the anchor net (3), and a prestress value F is applied to the joint support structure to be evaluated by an anchor cable mechanical property testing device P , a dynamic impact test of the anchor cable and the anchor net is conducted, and total elongation η Ⅱ , elastic deformation d Ⅱ , and energy absorption rate e Ⅱ of the anchor cable (1) in the joint support structure to be evaluated are obtained; According to the test results of the anchor cable and the prefabricated combined support structure, the comprehensive performance evaluation parameter K of the anchor cable (1) is calculated, and the calculation formula of the comprehensive performance evaluation parameter K is: ， Wherein, α, β, γ are equivalent transformation parameters, and θ is an energy reduction coefficient; The energy absorption rate e I And the energy absorption rate e II The formula is: 、 ， wherein E T is the total energy generated by the falling weight during the entire test, D T-I and D T-II is the total extension of the cable from the original length until the breaking point. The total elongation η I and the total elongation η II The calculation formula is: 、 ， Wherein, L is the original length of the anchor cable; the elastic deformation amount d I and the elastic deformation amount d II the calculation formula is: 、 ， where d L is the maximum deformation of the anchor cable for each impact.

2. The method according to claim 1, characterized in that, The anchor cable performance testing device comprises a first support (4), a first hydraulic loading oil cylinder (5), a first electromagnetic lock (6), a first drop hammer (7) and a first laser range finder, the first hydraulic loading oil cylinder (5) is connected to the bottom of the first support (4), the top end of the anchor cable (1) is connected to the first support (4), the bottom end of the anchor cable (1) is connected to the first hydraulic loading oil cylinder (5), so as to apply static load to the anchor cable (1) through the first hydraulic loading oil cylinder (5), the first electromagnetic lock (6) is connected to the top of the first support (4), the first drop hammer (7) is magnetically connected to the first electromagnetic lock (6), so as to apply dynamic load to the anchor cable (1), and the first laser range finder is arranged at the top of the first support (4) to obtain test data of the anchor cable (1).

3. The anchor cable dynamic-static mechanical property comprehensive evaluation method according to claim 2, wherein The anchor cable mechanical property testing device applies a prestress value F to the anchor cable (1) on site P-I , carries out a dynamic-static coupling test of the anchor cable (1), and obtains total elongation η I , elastic deformation d I , and energy absorption rate e I of the anchor cable (1), and the method comprises the following steps: A length L of the anchor cable (1) is inserted into the limiting hole at the top of the first support (4), the top end of the anchor cable (1) is fixed to the first support (4) through a lock (14), and the bottom end of the anchor cable (1) is fixed to the first hydraulic loading oil cylinder (5) through the lock (14). The first hydraulic loading oil cylinder (5) is used to apply a pre-stress value F to the anchor cable (1) under test P-I and stabilize the anchor cable (1) under test for a period of time; According to the test requirements, the height of the first drop hammer (7) to the bottom end of the anchor cable (1) is h, so as to generate impact energy E on the anchor cable (1) by releasing the first drop hammer (7) through the first electromagnetic lock (6) I The impact load is the maximum deformation d of the anchor cable in this impact recorded by the first laser range finder L ; Repeating the pre-stress value F on the anchor cable (1) through the first hydraulic loading oil cylinder (5) P-I And releasing the impact energy E generated by the first drop hammer (7) on the anchor cable (1) through the first electromagnetic lock (6) I The impact load, using the first laser range finder to record the maximum deformation d of the anchor cable in this impact L Until the anchor cable (1) breaks, and the maximum tensile amount D of the anchor cable (1) is obtained through the first laser range finder T-I .

4. The anchor cable dynamic-static mechanical property comprehensive evaluation method according to claim 2, wherein The anchor cable performance testing device further comprises a second support (8), a tray (9), a second electromagnetic lock (10), a second drop hammer (11), a second hydraulic loading oil cylinder (12), a second laser range finder and a stress monitor, the tray (9) is arranged at the bottom of the second support (8), the combined support structure is arranged on the tray (9), the second electromagnetic lock (10) is connected to the top of the second support (8), the second drop hammer (11) is magnetically connected to the second electromagnetic lock (10), so that the second drop hammer (11) applies dynamic load to the combined support structure, the second hydraulic loading oil cylinder (12) is connected to the top of the first support (4), the output end of the second hydraulic loading oil cylinder (12) is provided with a loading plate (13), the loading plate (13) abuts against the top surface of the combined support structure, so as to apply static load to the combined support structure, and the second laser range finder and the stress monitor are arranged at the top of the second support (8) respectively, so as to obtain test data of the combined support structure.

5. The method according to claim 4, characterized in that, The rock mass simulation material (2), the evaluated anchor cable (1), and the anchor mesh (3) are used to construct the evaluated combined support structure. The prestress value F is applied to the evaluated combined support structure according to the field conditions using the anchor cable mechanical performance testing device. P An anchor-net dynamic impact test was conducted to obtain the total elongation η of the evaluated anchor cable (1) in the evaluated combined support structure. Ⅱ Elastic deformation d Ⅱ and energy absorption rate e Ⅱ include: The rock mass simulation material (2) is prefabricated according to the actual rock mass mechanical parameters on site, the rock mass simulation material (2) is drilled and placed into the anchor cable (1) according to the spacing between the anchors on site, the anchor net (3) is arranged below the rock mass simulation material (2) and is fixed with the anchor cable (1) and the rock mass simulation material (2) to form an integral whole, the top of the anchor cable (1) is fixed to the top of the second support (8) through a lock (14), and the rock mass simulation material (2) is fixed to the tray (9) through the lock (14). The second hydraulic loading oil cylinder (12) and the loading plate (13) abut against the evaluated joint support structure, and a prestress value F is applied to the evaluated anchor cable (1) P , according to the test requirements, the height of the second falling hammer (11) to the top of the evaluated joint support structure is h, so as to release the impact energy E of the second falling hammer (11) on the evaluated joint support structure through the second electromagnetic lock (10) II , and the maximum deformation d of the anchor cable in this impact is recorded by using the second laser range finder L ; Repeat the previous step until the anchor cable (1) under test breaks and the total extension length D of the anchor cable (1) under test is obtained by the second laser range finder T-II .

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