Energy anchor rod and soil interface pull-out test device and friction resistance performance evaluation method

Abstract

The invention discloses an energy anchor rod and soil interface pull-out test device and a friction resistance performance evaluation method, and belongs to the technical field of anchor rod pull-out tests. The device comprises a grouting maintenance device and an energy device connected with the grouting maintenance device, wherein the grouting maintenance device comprises a sample cylinder, an upper cover plate, a lower cover plate, a centering top plug and a centering bottom plug; the energy device comprises a brass tube, a water bucket, a silicone tube, a water pump, a flow meter, a heating rod, a temperature controller, a reflection heat preservation film, a graphene heating film and a thermometer. The device has the advantages that the two energy devices are connected with the two brass pipes on the sample respectively, the temperature difference of the heat exchange pipes is artificially manufactured through different water temperatures of the two devices, and the summer working condition and the winter working condition of the actual energy anchor rod are simulated; according to the method provided by the invention, the friction resistance performance of the energy anchor rod and the soil interface can be evaluated, and the influence of an energy device on the anchor-soil interface under different temperature loading working conditions is judged.

Description

Technical Field

[0001] The invention belongs to the technical field of anchor rod pull-out test, and in particular relates to a pull-out test device for an energy anchor rod and soil interface and a friction resistance performance evaluation method. Background Art

[0002] Shallow geothermal energy resources are widely distributed, with abundant reserves, and their distribution depth is highly consistent with the construction objects of geotechnical structures. Therefore, combining ground-source heat pump technology with traditional underground construction structures has a strong combination effect, which can meet the dual functions of bearing the upper structure load and obtaining shallow geothermal energy.

[0003] At present, energy piles, as one of the typical representatives of the above-mentioned structural combination, have been widely used in actual projects. As a means of slope support and management, anchor rods are widely used in mountain roads and railways, and they have certain similarities with pile foundations in terms of working environment, material properties, morphological appearance, and force characteristics. Therefore, they can also be combined with ground source heat pump technology to form a new type of underground structure with integrated support and heat exchange functions, namely energy anchor rods.

[0004] However, there are few technical means to study energy anchors at present. Only relevant scholars have discussed the influence of temperature on the internal force of anchors, and there are almost no field tests on the heat exchange efficiency and heat transfer characteristics of energy anchors. The analysis methods are mainly concentrated on numerical simulation, so there is a lack of actual test data as a strong support. Secondly, field tests are subject to various factors, and have disadvantages such as time-consuming, labor-intensive, low repeatability, and high cost. Only some universities or scientific research institutions have the conditions to conduct tests.

[0005] Chinese patent (CN103940652A) discloses a sample preparation device and method for testing the friction performance of the interface between anchor or pile and soil. However, this technical solution has the following shortcomings:

[0006] (1) The soil sample tube is not equipped with small holes for exhaust during compaction, resulting in poor compaction effect of the soil layer and obvious stratification of the soil layer, especially at the outer edge of the adobe, where the uniformity of the adobe is poor.

[0007] (2) Due to the lack of energy devices, it is impossible to explore the influence of energy devices (mainly circulating fluid temperature, flow rate, etc.) on the anchor bolt-soil interface strength.

[0008] (3) There is a lack of evaluation methods for the friction performance of the energy anchor and soil interface, which makes it impossible to determine the impact of the energy device on the anchor-soil interface under different temperature loading conditions.

[0009] Therefore, it is imperative to develop a set of energy anchor bolt-soil interface instantaneous pull-out test equipment and test methods that are simple, easy, lightweight, easily disassembled, highly repeatable, and consistent with actual working conditions. Summary of the invention

[0010] The purpose of the embodiments of the present invention is to overcome at least one of the above-mentioned technical deficiencies and to provide a pull-out test device for an energy anchor rod and soil interface and a friction performance evaluation method, which can solve at least one technical problem in the background technology.

[0011] In order to achieve the above technical objectives, an embodiment of the present invention provides a pull-out test device for an energy anchor rod and a soil interface, comprising a grouting and curing device and an energy device connected to the grouting and curing device, wherein:

[0012] The grouting and curing device comprises a sample tube, an upper cover plate, a lower cover plate, a centering top plug and a centering bottom plug, wherein the upper cover plate and the lower cover plate are respectively covered with the upper and lower opening ends of the sample tube; the centering top plug is fixedly arranged on the upper cover plate, the centering bottom plug is fixedly arranged on the lower cover plate and is arranged opposite to the centering top plug, the centering top plug is penetrated with a first through hole for inserting an anchoring steel bar and two second through holes for inserting a brass tube, the centering bottom plug is provided with a first centering hole opposite to the first through hole and used for centering the anchoring steel bar and two second centering holes opposite to the second through hole and used for centering the brass tube; a thermometer insertion hole is penetrated on the side wall of the sample tube;

[0013] The energy device includes a brass tube, a water bucket, a silicone tube, a water pump, a flow meter, a heating rod, a thermostat, a reflective insulation film, a graphene heating film and a thermometer. There are two brass tubes, which are respectively inserted into the grouting and curing device; there are two water buckets, which are respectively connected to the two brass tubes through the silicone tube; the water pump and the flow meter are arranged on the silicone tube; the heating rod is placed in the water bucket; the thermostat is connected to the heating rod; the reflective insulation film is arranged on the inner surface of the grouting and curing device; the graphene heating film is coated on the outer peripheral surface of the sample tube; and the thermometer is inserted into the grouting and curing device through the thermometer insertion hole on the sample tube.

[0014] Optionally, it also includes an upper silicone pad arranged between the upper cover plate and the sample tube and a lower silicone pad arranged between the lower cover plate and the sample tube.

[0015] Optionally, the reflective heat-insulating film is arranged on the upper and lower surfaces of the sample tube.

[0016] Optionally, the energy device also includes a water outlet valve arranged at the bottom of the bucket.

[0017] The present invention also provides a friction performance evaluation method based on the energy anchor rod and soil interface pull-out test device, comprising:

[0018] Step S1, providing a pull-out test device for the interface between an energy anchor rod and soil, and placing the prepared energy anchor rod sample into the pull-out test device;

[0019] Step S2, start the universal testing machine, select the displacement control loading mode, perform the energy anchor pull-out test at a certain loading rate, stop the universal testing machine and the energy device after reaching a predetermined slip amount, and obtain test data;

[0020] Step S3, based on the obtained test data, the interface shear-slip curve of the energy anchor can be obtained by formula conversion, and the following data can be obtained from the interface shear-slip curve: the peak shear strength τ of the energy anchor f1 , the shear displacement s corresponding to the peak shear strength of the energy anchor f1 and the residual shear strength τ of the energy anchor r1 ;

[0021] Step S4, establishing a friction performance evaluation model for the energy anchor and soil interface, specifically including:

[0022] Step S41, assuming that the direction and trend of the interface shear-slip curve of the energy anchor are close to those of the ordinary unit anchor, and defining τ f is the peak shear strength of ordinary anchor rod, s f is the shear displacement corresponding to the peak shear strength of the ordinary anchor, τ r is the residual shear strength of ordinary anchor;

[0023] Step S42: The peak shear strength τ of the energy anchor f1 Compared with the peak shear strength of ordinary anchors f For comparison, when τ f1 ≥1.1τ f When τ f1 ≤0.9τ f When τ f1 Satisfy 0.9τ f <τ f1 <1.1τ f , then execute step S43 to establish a simultaneous consideration of s f1 and τ r1 Evaluation model of

[0024] Step S43, consider

[0025] In the formula, is the corrected peak shear displacement of the energy anchor;

[0026] consider

[0027] In the formula, is the corrected residual shear strength of the energy anchor;

[0028] Step S44, set

[0029] In the formula, ξ 1 is the model evaluation number corresponding to the peak shear displacement of the energy anchor;

[0030] make

[0031] In the formula, ξ 2 is the model evaluation number corresponding to the residual shear strength of the energy anchor;

[0032] Substituting equation (1) and equation (2) into equation (3) and equation (4) respectively, we get:

[0033]

[0034] Step S45, consider

[0035] In the formula, is the model evaluation number ξ corresponding to the peak shear displacement of the energy anchor 1 The model evaluation number ξ corresponding to the residual shear strength of the energy anchor 2 A piecewise function of , used to weight the model evaluation number;

[0036] consider

[0037] consider

[0038] Step S46, consider the model evaluation formula:

[0039] Where ξ is the model evaluation number;

[0040] Substituting equations (5), (6), (7), (8) and (9) into equation (10), we can obtain the specific result of the model evaluation number ξ. When When the peak shear strength of the energy anchor corresponds to the shear displacement s f1 The main impact is on the anchor-soil interface;

[0041] Step S5, based on the model evaluation number ξ and the peak shear strength τ of the energy anchor in the curve element f1 , the shear displacement s corresponding to the peak shear strength of the energy anchor f1 and the residual shear strength τ of the energy anchor r1 The relative size relationship between them is used to evaluate the friction resistance of the energy anchor and soil interface.

[0042] Optionally, step S5 specifically includes:

[0043] Step S51, comparing Table 1, obtaining the friction performance evaluation of the interface between the energy anchor and the soil;

[0044] Table 1 Evaluation table of friction performance between energy anchor and soil interface

[0045]

[0046] Step S52, search the following details to obtain a detailed evaluation of the friction performance of the energy anchor and soil interface:

[0047] a. Comprehensive evaluation: favorable;

[0048] When τ f1 ≥1.1τ f When the energy anchor rod has a higher peak shear strength than the ordinary anchor rod, it can be judged that: under the current temperature loading condition, the energy device is beneficial to stabilize the anchor-soil interface strength, and the energy anchor rod has a higher ability to resist pull-out shear failure;

[0049] When f1 ≥1.05s f , τ r1 ≥1.05τ r When ξ>0, the peak shear displacement and residual shear strength of the energy anchor are higher than those of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, the energy device is beneficial to stabilizing the anchor-soil interface. More displacement is required to achieve the same peak shear strength, that is, the displacement safety threshold is higher, and a higher residual shear strength can be maintained after destruction.

[0050] When f1 ≥1.05s f , 0.95τ r <τ r1 <1.05τ r When ξ>0, the peak shear displacement of the energy anchor is higher than that of the ordinary unit anchor, and the residual shear strength is close to that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, the energy device is beneficial to stabilizing the anchor-soil interface, and more displacement is required to achieve the same peak shear strength, that is, the displacement safety threshold is higher;

[0051] When 0.95s f f1 <1.05s f , τ r1 ≥1.05τ r ​When ξ>0, the peak shear strength of the energy anchor is close to that of the common unit anchor, but the residual shear strength is higher than that of the common unit anchor. It can be judged that: under the current temperature loading condition, the energy device is beneficial to stabilizing the anchor-soil interface and improves the residual shear strength of the energy anchor after being destroyed.

[0052] b. Comprehensive evaluation: generally favorable;

[0053] When f1 ≥1.05s f , τ r1 ≤0.95τ r , ξ>0, that is, the peak shear displacement of the energy anchor is higher than that of the ordinary unit anchor, but the residual shear strength is lower than that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, from the former point of view, the energy device is beneficial to the stabilization of the anchor-soil interface; from the latter point of view, the energy device has a deterioration effect on the stabilization of the anchor-soil interface. At this time, the model evaluation number ξ>0, indicating that the degradation τ r1 The impact is less than the favorable f1 Therefore, the energy device is generally beneficial to stabilizing the anchor-soil interface;

[0054] When f1 ≤0.95s f , τ r1 ≥1.05τ r , ξ>0, that is, the peak shear displacement of the energy anchor is lower than that of the ordinary unit anchor, but the residual shear strength is higher than that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, from the former point of view, the energy device has a deteriorating effect on stabilizing the anchor-soil interface; from the latter point of view, the energy device is beneficial to stabilizing the anchor-soil interface. At this time, the model evaluation number ξ>0, which means that even if the weighted emphasis is given to s f1 In the case of favorable τ r1 The impact is still greater than the degradation f1 Therefore, the energy device is generally beneficial to stabilizing the anchor-soil interface;

[0055] When f1 ≥1.05s f , τ r1 ≤0.95τ r , ξ=0, which is a special case, that is, the peak shear displacement of the energy anchor is lower than that of the ordinary unit anchor, but the residual shear strength is higher than that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, the system evaluation number ξ=0, indicating that the degradation τ r1 The degree of influence and benefits f1 The impact is similar, but in order to focus on s f1 ,Therefore, the energy device is generally beneficial to stabilizing the anchor-soil interface;

[0056] c. Comprehensive evaluation: overall deterioration;

[0057] When f1 ≥1.05s f , τ r1 ≤0.95τ r , ξ<0, that is, the peak shear displacement of the energy anchor is higher than that of the ordinary unit anchor, but the residual shear strength is lower than that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, from the former point of view, the energy device is beneficial to the stabilization of the anchor-soil interface; from the latter point of view, the energy device has a deterioration effect on the stabilization of the anchor-soil interface. At this time, the system evaluation number ξ<0, indicating that the degradation τ r1 The impact is greater than the positive f1 The degree of influence, therefore, the overall deterioration of the energy device on the stable anchor-soil interface;

[0058] When f1 ≤0.95s f , τ r1 ≥1.05τ r , ξ<0, that is, the peak shear displacement of the energy anchor is lower than that of the ordinary unit anchor, but the residual shear strength is higher than that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, from the former point of view, the energy device has a deteriorating effect on stabilizing the anchor-soil interface; from the latter point of view, the energy device is beneficial to stabilizing the anchor-soil interface. At this time, the system evaluation number ξ<0, indicating that it is favorable τ r1 The impact is less than the degradation s f1 The degree of influence, therefore, the overall deterioration of the energy device on the stable anchor-soil interface;

[0059] When f1 ≤0.95s f , τ r1 ≥1.05τ r , ξ=0, which is a special case, that is, the peak shear displacement of the energy anchor is lower than that of the ordinary unit anchor, but the residual shear strength is higher than that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, the system evaluation number ξ=0, indicating that the favorable τ r1 The degree of influence and degradation f1 The impact is similar, but in order to focus on s f1 ,Therefore, the energy device is generally deteriorated for stabilizing the anchor-soil interface;

[0060] d. Comprehensive evaluation: deterioration;

[0061] When τ f1 ≤0.9τ fWhen the energy anchor rod has a lower peak shear strength than the ordinary anchor rod, it can be judged that: under the current temperature loading condition, the energy device has a deteriorating effect on the strength of the anchor-soil interface, and the energy anchor rod has a lower ability to resist pull-out shear failure;

[0062] When f1 ≤0.95s f , τ r1 ≤0.95τ r When ξ<0, the peak shear displacement and residual shear strength of the energy anchor are lower than those of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, the energy device has a deteriorating effect on the stabilization of the anchor-soil interface. Less displacement is required to achieve the same peak shear strength, that is, the displacement safety threshold is lower, and a lower residual shear strength is maintained after damage.

[0063] When 0.95s f f1 <1.05s f , τ r1 ≤0.95τ r When ξ<0, the peak shear strength of the energy anchor is close to that of the ordinary unit anchor, but the residual shear strength is lower than that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, the energy device has a deteriorating effect on the stabilization of the anchor-soil interface, which reduces the residual shear strength of the energy anchor after being destroyed.

[0064] When f1 ≤0.95s f , 0.95τ r <τ r1 <1.05τ r When ξ<0, the peak shear displacement of the energy anchor is lower than that of the ordinary unit anchor, and the residual shear strength is close to that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, the energy device has a deteriorating effect on the stabilization of the anchor-soil interface, and less displacement is required to achieve the same peak shear strength, that is, the displacement safety threshold is lower;

[0065] e. Comprehensive evaluation: no impact;

[0066] When 0.95s f f1 <1.05s f , 0.95τ r <τ r1 <1.05τ r When ξ=0, the shear-slip curve of the energy anchor is close to that of the ordinary unit anchor, and the three key curve elements considered are close. It can be judged that under the current temperature loading condition, the energy device has basically no effect on stabilizing or deteriorating the anchor-soil interface.

[0067] ​​The advantages of the present invention are:

[0068] 1. The present invention provides a centering top plug and a centering bottom plug. Compared with the traditional centering device, the present invention increases the hole for inserting the brass tube, reduces the height of the centering top plug, and newly increases the hole for vibration.

[0069] 2. The upper cover plate provided by the present invention can be used for both steel bar centering and grouting material maintenance. When used in combination with a centering plug, it can significantly reduce soil moisture content changes and avoid test distortion compared to traditional bagging protection.

[0070] 3. The sample tube provided by the present invention is provided with a thermometer insertion hole, which can be used to insert a soil layer thermometer probe to monitor the relationship between soil layer temperature and time during the heat exchange cycle of the sample; for artificially produced ordinary soil samples, the stratification phenomenon of the soil layer can be reduced during the stratified compaction process;

[0071] 4. The present invention uses two sets of energy devices to connect the two brass tubes on the sample respectively. The water temperatures of the two sets of devices are different, and the temperature difference of the heat exchange tube is artificially created to simulate the summer and winter working conditions of the actual energy anchor.

[0072] 5. The method provided by the present invention can evaluate the friction performance of the energy anchor and soil interface, and determine the impact of the energy device on the anchor-soil interface under different temperature loading conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0074] Figure 1 A schematic diagram of the explosion structure of the grouting curing device provided by the present invention;

[0075] Figure 2 A schematic diagram of the overall cross-sectional structure of the grouting curing device provided by the present invention;

[0076] Figure 3 A schematic diagram of the sample tube structure provided by the present invention;

[0077] Figure 4 A schematic diagram of the structure of the centering plug provided by the present invention;

[0078] Figure 5 A schematic diagram of the structure of the centering bottom plug provided by the present invention;

[0079] Figure 6The overall structural schematic diagram of the energy anchor rod and soil interface pull-out test device provided by the present invention;

[0080] Figure 7 This is a comparison diagram of the sliding-shear curves of two groups of unit energy anchor rods in Example 1 provided by the present invention and two groups of ordinary anchor rod curves. DETAILED DESCRIPTION

[0081] This embodiment clearly and completely describes a friction performance evaluation method based on a high-efficiency composite solid waste sludge solidification technology and its energy anchor and soil interface pull-out test device in conjunction with a soft soil foundation treatment project of a ring expressway in a soft soil area. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0082] See also Figure 1 , Figure 2 and Figure 6 As shown, the present invention provides a pull-out test device for an energy anchor rod and soil interface, comprising a grouting and curing device and an energy device connected to the grouting and curing device.

[0083] The grouting and curing device comprises a sample tube 1, an upper cover plate 2, a lower cover plate 3, an upper silicone pad 4, a lower silicone pad 5, a centering top plug 6 and a centering bottom plug 7. The upper cover plate 2 and the lower cover plate 3 are respectively connected to the upper and lower opening ends of the sample tube 1.

[0084] Recombination Figure 3 As shown, the side wall of the sample tube 1 is penetrated with a thermometer insertion hole 10. Specifically, the sample tube 1 is made of organic glass, and a plurality of the thermometer insertion holes 10 are arrayed along the height direction of the sample tube 1. The thermometer insertion holes 10 are circular holes with a diameter of 4 mm and are cut by laser.

[0085] The centering top plug 6 is fixedly disposed on the upper cover plate 2 , and the centering bottom plug 7 is fixedly disposed on the lower cover plate 3 and is arranged opposite to the centering top plug 6 .

[0086] Recombination Figure 4 and Figure 5 As shown, the centering top plug 6 is penetrated by a first through hole 61 for inserting the anchoring steel bar 9 and two second through holes 62 for inserting the brass tube 11, and the centering bottom plug 7 is provided with a first centering hole 71 opposite to the first through hole 61 and used for centering the anchoring steel bar 9 and two second centering holes 72 opposite to the second through hole 62 and used for centering the brass tube 11.

[0087] Specifically, the diameter of the first through hole 61 is larger than that of the second through hole 62 , and two second through holes 62 are respectively arranged on the left and right sides of the first through hole 61 .

[0088] Furthermore, the centering plug 6 is also provided with a pair of semicircular through holes 63 for grouting and vibration.

[0089] The energy device includes the brass tube 11, a water bucket 12, a silicone tube 13, a water pump 14, a flow meter 15, a heating rod 16, a thermostat 17, a reflective insulation film 18, a graphene heating film 19 and a thermometer 20. There are two brass tubes 11, which are respectively inserted into the grouting curing device.

[0090] There are two water buckets 12 , which are connected to the two brass tubes 11 through the silicone tube 13 .

[0091] The water pump 14 and the flow meter 15 are disposed on the silicone tube 13 .

[0092] The heating rod 16 is placed in the water bucket 12 , and the thermostat 17 is connected to the heating rod 16 to control the heating of the heating rod 16 .

[0093] The reflective heat-insulating film 18 is disposed on the upper and lower surfaces of the sample tube 1 , and the graphene heating film 19 is coated on the outer peripheral side surface of the sample tube 1 .

[0094] The thermometer 20 is inserted into the sample tube 1 through the thermometer insertion hole 10 on the sample tube 1 .

[0095] The energy device further includes a water outlet valve 21 disposed at the bottom of the water bucket 12 .

[0096] It should be noted that the anchoring steel bar 9 and the energy device together constitute the energy anchor rod.

[0097] Recombination Figure 6 As shown, the method of using the energy anchor rod and soil interface pull-out test device provided by the present invention is as follows:

[0098] Step 1, preparing a 3D printed geopolymer-based soil sample 22 containing cracks and holes according to a certain ratio;

[0099] Step 2: centralized maintenance of soil samples;

[0100] Step 3, trim the soil sample and then put it into the sample tube 1;

[0101] Step 4: After the upper and lower covers and the silicone pads are installed, the anchor steel bars 9 and the brass tube 11 are inserted into the centering bottom plug 7, and then the centering top plug 6 is installed. The grouting material is prepared according to a certain ratio (water: cement: sand = 0.45: 1: 1), and then the grouting is started using a funnel. At the same time, a small glass rod is used to vibrate to ensure density;

[0102] Step 5: After the cement has initially set, remove the centering plug 7 to prevent it from sticking and being unable to be removed;

[0103] Step 6: Use a sealed bag to bag the entire grouting curing device and start curing;

[0104] Step 7, open the sealed bag and place the entire grouting curing device in a room with a constant temperature (20°C to 25°C) for temperature balance;

[0105] Step 8, remove the upper and lower covers and the silicone pad, and place the sample tube 1 on the loading chassis, use a 4mm diameter drill bit to drill through the small hole on the side wall of the sample tube, and drill into the depth range from the outer edge of the soil sample to the outer edge of the anchor body;

[0106] Step 9, install the loading upper plate, and use the connecting piece 24 to connect the anchor steel bar 9 and the clamp 25;

[0107] Step 10, insert the thermometer 20, connect it to the energy device, and keep the device running to monitor the temperature value change;

[0108] Step 11, start the universal testing machine, select the displacement control loading mode, perform the pull-out test at a certain loading rate, and stop the universal testing machine and the energy device after reaching a predetermined slip amount;

[0109] Step 12: Obtain the pull-out force-displacement curve, convert it into the shear stress-displacement curve through the calculation formula, and finally compare it with the ordinary anchor rod (non-energy anchor rod) to evaluate the friction resistance performance of the energy anchor rod and the soil interface.

[0110] It should be further explained that the production process of 3D printed geopolymer-based soil samples is as follows:

[0111] ①Production process: mixing printing materials → printing unit samples → centralized maintenance → samples transported to the processing plant for cutting and surface finishing → finished products;

[0112] ② Printing ratio: The printing materials include the following components by weight: silica ash: 4-5 parts, fly ash: 3-3.6 parts, alkali-activated material (NaOH: NaSiO3 = 1:3): 0.33-0.5 parts, polypropylene fiber: 0.22-0.30 parts (1% volume dosage), copper tailings: 2-2.5 parts, blast furnace slag: 2-2.5 parts, thickener: 0.002-0.006 parts, water reducer: 0.009-0.011 parts, water: 4.4-6 parts; fine sand 7.5 parts; coarse sand 2.5 parts. The compressive strength of the filler made with the above ratio is 10MPa-60MPa. By adjusting the relationship between the above components, printing of soil samples with different strengths can be achieved;

[0113] ③ Printing material mixing and sample printing:

[0114] Step 1, 4-5 parts by weight of silica fume, 3-3.6 parts of fly ash, 2-2.5 parts of copper tailings, 2-2.5 parts of blast furnace slag, 7.5 parts of fine sand and 2.5 parts of coarse sand are mixed and stirred evenly;

[0115] Step 2, add 0.002-0.006 parts of thickener and mix well;

[0116] Step 3, add 0.009-0.011 parts of water reducer and 4.4-6 parts of water and mix well for 360-400 seconds;

[0117] Step 4, add 0.33-0.5 parts of alkali-activated material and mix well, stirring for 240-300 seconds;

[0118] Step 5: Add 0.22-0.30 parts of polypropylene fiber and mix well for 240-300 seconds. Then the unit printing ratio material can be obtained;

[0119] Step 6: Send the prepared unit printing ratio material to the print head of the 3D printer, and set the print head outlet cross-sectional area to 100-120mm 2 , horizontal printing speed is 150~180cm / min, vertical printing speed is 0.1~0.2m / h, extrusion speed is 0.01~0.02m 3 / h and then print to finally obtain a unit geopolymer-based printed soil sample.

[0120] The present invention also provides a friction performance evaluation method based on the energy anchor rod and soil interface pull-out test device, comprising:

[0121] Step S1, providing a pull-out test device for the interface between an energy anchor rod and soil, and placing the prepared energy anchor rod sample into the pull-out test device;

[0122] Step S2, start the universal testing machine, select the displacement control loading mode, perform the energy anchor pull-out test at a certain loading rate, stop the universal testing machine and the energy device after reaching a predetermined slip amount, and obtain test data;

[0123] Step S3, based on the obtained test data, the interface shear-slip curve of the energy anchor can be obtained by formula conversion, and the following data can be obtained from the interface shear-slip curve: the peak shear strength τ of the energy anchor f1 , the shear displacement s corresponding to the peak shear strength of energy anchor 9 f1 and the residual shear strength τ of the energy anchor r1 ;

[0124] Step S4, establishing a friction performance evaluation model for the energy anchor and soil interface, specifically including:

[0125] Step S41, assuming that the direction and trend of the interface shear-slip curve of the energy anchor are close to those of the ordinary unit anchor, and defining τ f is the peak shear strength of ordinary anchor rod, s f is the shear displacement corresponding to the peak shear strength of the ordinary anchor, τ r is the residual shear strength of ordinary anchor;

[0126] Step S42: The peak shear strength τ of the energy anchor f1 Compared with the peak shear strength of ordinary anchors f For comparison, when τ f1 ≥1.1τ f When τ f1 ≤0.9τ f When τ f1 Satisfy 0.9τ f <τ f1 <1.1τ f , then execute step S43 to establish a simultaneous consideration of s f1 and τ r1 Evaluation model of

[0127] Step S43, consider

[0128] In the formula, is the corrected peak shear displacement of the energy anchor;

[0129] consider

[0130] In the formula, is the corrected residual shear strength of the energy anchor;

[0131] Step S44, set

[0132] In the formula, ξ 1 is the model evaluation number corresponding to the peak shear displacement of the energy anchor;

[0133] make

[0134] In the formula, ξ 2 is the model evaluation number corresponding to the residual shear strength of the energy anchor;

[0135] Substituting equation (1) and equation (2) into equation (3) and equation (4) respectively, we get:

[0136]

[0137] Step S45, consider

[0138] In the formula, is the model evaluation number ξ corresponding to the peak shear displacement of the energy anchor 1 The model evaluation number ξ corresponding to the residual shear strength of the energy anchor 2 A piecewise function of , used to weight the model evaluation number;

[0139] consider

[0140] consider

[0141] Step S46, consider the model evaluation formula:

[0142] Where ξ is the model evaluation number;

[0143] Substituting equations (5), (6), (7), (8) and (9) into equation (10), we can obtain the specific result of the model evaluation number ξ. When When the peak shear strength of the energy anchor corresponds to the shear displacement s f1 The main impact is on the anchor-soil interface;

[0144] Step S5, based on the model evaluation number ξ and the peak shear strength τ of the energy anchor in the curve element f1 , the shear displacement s corresponding to the peak shear strength of the energy anchor f1 and the residual shear strength τ of the energy anchor r1 The relative size relationship between them is used to evaluate the friction resistance of the energy anchor and soil interface.

[0145] Step S5 specifically includes:

[0146] Step S51, referring to Table 1, quickly obtaining the friction performance evaluation of the interface between the energy anchor and the soil;

[0147] Table 1 Evaluation table of friction performance between energy anchor and soil interface

[0148]

[0149]

[0150] Step S52, search the following details to obtain a detailed evaluation of the friction performance of the energy anchor and soil interface:

[0151] a. Comprehensive evaluation: favorable;

[0152] When τ f1 ≥1.1τ f When the energy anchor rod has a higher peak shear strength than the ordinary anchor rod, it can be judged that: under the current temperature loading condition, the energy device is beneficial to stabilize the anchor-soil interface strength, and the energy anchor rod has a higher ability to resist pull-out shear failure;

[0153] When f1 ≥1.05s f , τ r1 ≥1.05τ r When ξ>0, the peak shear displacement and residual shear strength of the energy anchor are higher than those of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, the energy device is beneficial to stabilizing the anchor-soil interface. More displacement is required to achieve the same peak shear strength, that is, the displacement safety threshold is higher, and a higher residual shear strength can be maintained after destruction.

[0154] When f1 ≥1.05s f , 0.95τ r <τ r1 <1.05τ r When ξ>0, the peak shear displacement of the energy anchor is higher than that of the ordinary unit anchor, and the residual shear strength is close to that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, the energy device is beneficial to stabilizing the anchor-soil interface, and more displacement is required to achieve the same peak shear strength, that is, the displacement safety threshold is higher;

[0155] When 0.95s f f1 <1.05s f , τ r1 ≥1.05τ r When ξ>0, the peak shear strength of the energy anchor is close to that of the common unit anchor, but the residual shear strength is higher than that of the common unit anchor. It can be judged that: under the current temperature loading condition, the energy device is beneficial to stabilizing the anchor-soil interface and improves the residual shear strength of the energy anchor after being destroyed. ​

[0156] b. Comprehensive evaluation: generally favorable;

[0157] When f1 ≥1.05s f , τ r1 ≤0.95τ r , ξ>0, that is, the peak shear displacement of the energy anchor is higher than that of the ordinary unit anchor, but the residual shear strength is lower than that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, from the former point of view, the energy device is beneficial to the stabilization of the anchor-soil interface; from the latter point of view, the energy device has a deterioration effect on the stabilization of the anchor-soil interface. At this time, the model evaluation number ξ>0, indicating that the degradation τ r1 The impact is less than the favorable f1 Therefore, the energy device is generally beneficial to stabilizing the anchor-soil interface;

[0158] When f1 ≤0.95s f , τ r1 ≥1.05τ r , ξ>0, that is, the peak shear displacement of the energy anchor is lower than that of the ordinary unit anchor, but the residual shear strength is higher than that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, from the former point of view, the energy device has a deteriorating effect on stabilizing the anchor-soil interface; from the latter point of view, the energy device is beneficial to stabilizing the anchor-soil interface. At this time, the model evaluation number ξ>0, which means that even if the weighted emphasis is given to s f1 In the case of favorable τ r1 The impact is still greater than the degradation f1 Therefore, the energy device is generally beneficial to stabilizing the anchor-soil interface;

[0159] When f1 ≥1.05s f , τ r1 ≤0.95τ r , ξ=0, which is a special case, that is, the peak shear displacement of the energy anchor is lower than that of the ordinary unit anchor, but the residual shear strength is higher than that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, the system evaluation number ξ=0, indicating that the degradation τ r1 The degree of influence and benefits f1 The impact is similar, but in order to focus on s f1 ,Therefore, the energy device is generally beneficial to stabilizing the anchor-soil interface;

[0160] c. Comprehensive evaluation: overall deterioration;

[0161] When f1 ≥1.05s f , τ r1 ≤0.95τ r, ξ<0, that is, the peak shear displacement of the energy anchor is higher than that of the ordinary unit anchor, but the residual shear strength is lower than that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, from the former point of view, the energy device is beneficial to the stabilization of the anchor-soil interface; from the latter point of view, the energy device has a deterioration effect on the stabilization of the anchor-soil interface. At this time, the system evaluation number ξ<0, indicating that the degradation τ r1 The impact is greater than the positive f1 The degree of influence, therefore, the overall deterioration of the energy device on the stable anchor-soil interface;

[0162] When f1 ≤0.95s f , τ r1 ≥1.05τ r , ξ<0, that is, the peak shear displacement of the energy anchor is lower than that of the ordinary unit anchor, but the residual shear strength is higher than that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, from the former point of view, the energy device has a deteriorating effect on stabilizing the anchor-soil interface; from the latter point of view, the energy device is beneficial to stabilizing the anchor-soil interface. At this time, the system evaluation number ξ<0, indicating that it is favorable τ r1 The impact is less than the degradation s f1 The degree of influence, therefore, the overall deterioration of the energy device on the stable anchor-soil interface;

[0163] When f1 ≤0.95s f , τ r1 ≥1.05τ r , ξ=0, which is a special case, that is, the peak shear displacement of the energy anchor is lower than that of the ordinary unit anchor, but the residual shear strength is higher than that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, the system evaluation number ξ=0, indicating that the favorable τ r1 The degree of influence and degradation f1 The impact is similar, but in order to focus on s f1 ,Therefore, the energy device is generally deteriorated for stabilizing the anchor-soil interface;

[0164] d. Comprehensive evaluation: deterioration;

[0165] When τ f1 ≤0.9τ f When the energy anchor rod has a lower peak shear strength than the ordinary anchor rod, it can be judged that: under the current temperature loading condition, the energy device has a deteriorating effect on the strength of the anchor-soil interface, and the energy anchor rod has a lower ability to resist pull-out shear failure;

[0166] When f1 ≤0.95s f , τ r1 ≤0.95τ rWhen ξ<0, the peak shear displacement and residual shear strength of the energy anchor are lower than those of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, the energy device has a deteriorating effect on the stabilization of the anchor-soil interface. Less displacement is required to achieve the same peak shear strength, that is, the displacement safety threshold is lower, and a lower residual shear strength is maintained after damage.

[0167] When 0.95s f f1 <1.05s f , τ r1 ≤0.95τ r When ξ<0, the peak shear strength of the energy anchor is close to that of the ordinary unit anchor, but the residual shear strength is lower than that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, the energy device has a deteriorating effect on the stabilization of the anchor-soil interface, which reduces the residual shear strength of the energy anchor after being destroyed.

[0168] When f1 ≤0.95s f , 0.95τ r <τ r1 <1.05τ r When ξ<0, the peak shear displacement of the energy anchor is lower than that of the ordinary unit anchor, and the residual shear strength is close to that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, the energy device has a deteriorating effect on the stabilization of the anchor-soil interface, and less displacement is required to achieve the same peak shear strength, that is, the displacement safety threshold is lower;

[0169] e. Comprehensive evaluation: no impact;

[0170] When 0.95s f f1 <1.05s f , 0.95τ r <τ r1 <1.05τ r When ξ=0, the shear-slip curve of the energy anchor is close to that of the ordinary unit anchor, and the three key curve elements considered are close. It can be judged that under the current temperature loading condition, the energy device has basically no effect on stabilizing or deteriorating the anchor-soil interface.

[0171] The energy anchor rod and soil interface pull-out test device and the friction resistance performance evaluation method provided by the present invention are described in detail with specific embodiments below.

[0172] Embodiment 1

[0173] ​​Referring to the Chinese patent: A sample blank making device and method for testing the friction performance of the interface between anchor or pile and soil, publication number CN103940652A, adobe was made, and the basic physical properties of the remolded soil used are shown in Table 2 below. The shear resistance index of the soil measured by the direct shear test is shown in Table 3 below. The energy device was set to summer working conditions, with an ambient temperature of 25°C, a high temperature side temperature of 38°C, a low temperature measurement temperature of 35°C, a temperature difference of 3°C, and continuous heating for 9 hours.

[0174] Table 2: Basic physical properties of soil samples

[0175] Liquid limit / % Plastic limit / % Natural moisture content / % <![CDATA[Natural density / g / cm 3 > 35.24 18.98 23.98 1.55

[0176] Table 3: Soil shear resistance index obtained from direct shear test

[0177]

[0178] Adobe production: Referring to the Chinese patent: A sample production device and method for testing the friction performance of the interface between anchor or pile and soil, publication number CN103940652A, the adobe is produced, the radius of the adobe is 150mm, and the diameter of the middle anchor hole is 48mm.

[0179] Preparation and use of grouting curing device: In order of precedence, fix the sample tube and lower cover plate, lower silicone pad, upper silicone pad, and upper cover plate, and then slowly put the centering bottom plug from the soil sample anchor hole from top to bottom until it touches the bottom. Next, insert the anchor steel bar (HRB400, nominal diameter 10mm, length 230mm) and two brass tubes (tube inner diameter 4mm, outer diameter 5mm, length 120mm), and use the split-type centering top plug for fixed restraint. Subsequently, prepare the grouting material according to the mix ratio (water: standard sand: PO42.5 cement = 0.45:1:1), mix it thoroughly, use a funnel to assist in grouting, and use a small glass rod to vibrate to ensure density.

[0180] Removing the centering bottom plug: To prevent the cement mortar from sticking to the centering bottom plug after hardening, remove the centering bottom plug after the initial setting of the cement is completed.

[0181] Bag curing: Use a sealed bag to cover the entire grouting curing device and start curing for 7 days.

[0182] Temperature balance: Open the sealed bag and place the entire grouting curing device in a room with a constant temperature (25°C) for temperature balance.

[0183] Dismantling and drilling of grouting curing device: remove the upper and lower covers and silicone pads, place the sample tube on the loading chassis, use a 4mm diameter drill bit to drill through the small holes on the side wall of the sample tube, and the drilling depth is a group of three small holes at the same angle but different heights of the sample tube, which are 25mm, 50mm, 75mm and 100mm respectively.

[0184] Install the loading device: Install the loading upper plate and use connectors to connect the anchor steel bars and clamps.

[0185] Turn on the energy device: insert the soil thermometer and connect the energy device. Set the water temperature of the first energy device to a constant 38°C and the second energy device to a constant 35°C. Run the device for 9 hours and monitor the changes in the temperature count.

[0186] Start the universal testing machine: After the energy device has been running for 9 hours, select the displacement control loading mode, perform an instantaneous pull-out test at a certain loading rate (1 mm / min), and stop the universal testing machine and the energy device after the predetermined slip amount (20 mm) is reached.

[0187] Evaluation of interface friction performance: obtain the pull-out force-displacement curve, and convert the shear stress-displacement curve through the calculation formula, see Figure 7 As shown, the friction resistance performance of the energy anchor and soil interface is evaluated by comparing with ordinary anchors (non-energy anchors).

[0188] The friction performance evaluation method of the energy anchor rod and soil interface pull-out test device provided by the present invention comprises the following steps:

[0189] Step 1: Use the instantaneous pull-out test device to test the unit energy anchor to obtain the shear slip curve of the unit energy anchor. According to two sets of parallel tests, the following data are obtained from the curve data: τ f1 =30.7 kPa; s f1 =3.03mm; τ r1 =16.25kPa.

[0190] Step 2: Establish a friction performance evaluation model for the unit energy anchor and soil interface.

[0191] Process 1: Assume that the direction and trend of the shear-slip curve of the unit energy anchor bolt soil interface are similar to those of the ordinary unit anchor bolt. After two sets of parallel tests, the results are: τ f =20.8kPa;s f =3.29mm; τ r =10.61kPa. The relative importance of the factors considered in the curve: τ f1 >>s f1 >τ r1 .

[0192] Step 2: τ f1 With τ f for comparison.

[0193] According to two groups of parallel experiments, τ f1 =30.7kPa>1.1τ f=22.88 kPa, therefore, go directly to step 3.

[0194] Step 3: Based on the model evaluation number ξ and curve element τ f1 、s f1 , τ r1 The relative size relationship between them is used to evaluate the friction resistance of the energy anchor and soil interface.

[0195] Process 1: Refer to Table 1 to quickly evaluate the friction performance of the energy anchor and soil interface.

[0196] Overall evaluation: favorable.

[0197] Process 2: Find the evaluation criteria and obtain a detailed evaluation of the friction performance of the energy anchor and soil interface.

[0198] τ f1 =30.7kPa>1.1τ f =22.88kPa. That is, the energy anchor has a higher peak shear strength than the ordinary anchor. It can be judged that under the current temperature loading condition (the energy device is set to summer conditions, the high temperature side temperature is 38°C, the low temperature measurement temperature is 35°C, the temperature difference is 3°C, and the heating is continued for 9h), the energy device is beneficial to stabilizing the anchor-soil interface strength, and the energy anchor has a higher ability to resist pull-out shear failure.

[0199] Embodiment 2

[0200] The difference from the first embodiment is that the adobe is made of 3D printed geopolymer-based soil samples containing cracks and holes, the step of "adobe making" is subdivided into three steps, and the remaining steps are the same as the first embodiment.

[0201] Step S11, printing a geopolymer-based soil sample containing cracks and holes;

[0202] The printing materials include the following components by weight: silica fume: 4.4 parts, fly ash: 3.3 parts, alkali-activated material (NaOH: NaSiO 3 =1:3): 0.4 parts, polypropylene fiber: 0.25 parts (1% volume dosage), copper tailings: 2.3 parts, blast furnace slag: 2.3 parts, thickener: 0.004 parts, water reducer: 0.01 parts, water: 5.4 parts; fine sand 7.5 parts; coarse sand 2.5 parts. The compressive strength of the filler made with the above ratio is close to 30MPa. By adjusting the above component relationship, the printing of fillers with different strengths can be achieved. The specific operation is as follows:

[0203] Step S111, 4.4 parts by weight of silica fume, 3.3 parts by weight of fly ash, 2.3 parts by weight of copper tailings, 2.3 parts by weight of blast furnace slag, 7.5 parts by weight of fine sand and 2.5 parts by weight of coarse sand are mixed and stirred uniformly;

[0204] Step S112, adding 0.004 parts of thickener and mixing evenly;

[0205] Step S113, add 0.01 parts of water reducing agent and 5.4 parts of water, mix well and stir for 400 seconds;

[0206] Step S114, adding 0.4 parts of alkali-activated material and mixing evenly, the stirring time is 240 seconds;

[0207] Step S115, add 0.25 parts of polypropylene fiber and mix well for 300 seconds. Then the unit body printing ratio material can be obtained;

[0208] Step S116: Send the prepared unit printing ratio material to the print head of the 3D printer, and set the print head outlet cross-sectional area to 100mm 2 , horizontal printing speed is 160cm / min, vertical printing speed is 0.2m / h, extrusion speed is 0.02m 3 / h and then print to finally obtain a unit printed soil sample.

[0209] S12. Centralized curing of soil samples. After the printed soil samples have sufficient strength, they are placed in a curing room for curing for 7 days.

[0210] S13, cutting and surface finishing. The soil sample cured in S2 is transported to a processing plant for cutting and surface finishing, and the finished product is placed in a sample tube for standby use.

[0211] Embodiment 3

[0212] The difference from Example 1 and Example 2 is that: the adobe is made of reshaped soil sample or 3D printed geopolymer-based soil sample; the energy device is set to winter working conditions, the high temperature side temperature is 15°C, the low temperature measurement temperature is 0°C, the temperature difference is 15°C, and the cooling is continued for 9 hours by adding a cold source to the water bucket; the energy device adds a water outlet valve to discharge excess water; compared with Example 1, in the process of step "turning on the energy device", the heating rod is removed, and a circle of graphene heating film is required around the sample tube to keep the temperature at 25°C. The remaining steps are the same as Example 1.

[0213] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A pull-out test device for the interface between energy anchor rod and soil, characterized in that: It comprises a grouting and curing device and an energy device connected to the grouting and curing device, wherein: The grouting and curing device comprises a sample tube, an upper cover plate, a lower cover plate, a centering top plug and a centering bottom plug, wherein the upper cover plate and the lower cover plate are respectively covered with the upper and lower opening ends of the sample tube; the centering top plug is fixedly arranged on the upper cover plate, the centering bottom plug is fixedly arranged on the lower cover plate and is arranged opposite to the centering top plug, the centering top plug is penetrated with a first through hole for inserting an anchoring steel bar and two second through holes for inserting a brass tube, the centering bottom plug is provided with a first centering hole opposite to the first through hole and used for centering the anchoring steel bar and two second centering holes opposite to the second through hole and used for centering the brass tube; a thermometer insertion hole is penetrated on the side wall of the sample tube; The energy device includes a brass tube, a water bucket, a silicone tube, a water pump, a flow meter, a heating rod, a thermostat, a reflective insulation film, a graphene heating film and a thermometer. There are two brass tubes, which are respectively inserted into the grouting and curing device; there are two water buckets, which are respectively connected to the two brass tubes through the silicone tube; the water pump and the flow meter are arranged on the silicone tube; the heating rod is placed in the water bucket; the thermostat is connected to the heating rod; the reflective insulation film is arranged on the inner surface of the grouting and curing device; the graphene heating film is coated on the outer peripheral surface of the sample tube; and the thermometer is inserted into the grouting and curing device through the thermometer insertion hole on the sample tube.

2. The energy anchor rod and soil interface pull-out test device according to claim 1 is characterized in that: It also includes an upper silicone pad arranged between the upper cover plate and the sample tube and a lower silicone pad arranged between the lower cover plate and the sample tube.

3. The energy anchor rod and soil interface pull-out test device according to claim 1 is characterized in that: The reflective heat-insulating film is arranged on the upper and lower surfaces of the sample tube.

4. The energy anchor rod and soil interface pull-out test device according to claim 1 is characterized in that: The energy device also includes a water outlet valve arranged at the bottom of the water bucket.

5. A friction performance evaluation method for the energy anchor and soil interface pull-out test device according to any one of claims 1 to 4, characterized in that: include: Step S1, providing a pull-out test device for the interface between an energy anchor rod and soil, and placing the prepared energy anchor rod sample into the pull-out test device; Step S2, start the universal testing machine, select the displacement control loading mode, perform the energy anchor pull-out test at a certain loading rate, stop the universal testing machine and the energy device after reaching a predetermined slip amount, and obtain test data; Step S3, based on the obtained test data, the interface shear-slip curve of the energy anchor can be obtained by formula conversion, and the following data can be obtained from the interface shear-slip curve: the peak shear strength τ of the energy anchor f1 , the shear displacement s corresponding to the peak shear strength of the energy anchor f1 and the residual shear strength τ of the energy anchor r1 ; Step S4, establishing a friction performance evaluation model for the energy anchor and soil interface, specifically including: Step S41, assuming that the direction and trend of the interface shear-slip curve of the energy anchor are close to those of the ordinary unit anchor, and defining τ f is the peak shear strength of ordinary anchor rod, s f is the shear displacement corresponding to the peak shear strength of the ordinary anchor, τ r is the residual shear strength of ordinary anchor; Step S42: The peak shear strength τ of the energy anchor f1 Compared with the peak shear strength of ordinary anchors f For comparison, when τ f1 ≥1.1τ f When τ f1 ≤0.9τ f When τ f1 Satisfy 0.9τ f <τ f1 <1.1τ f , then execute step S43 to establish a simultaneous consideration of s f1 and τ r1 Evaluation model of Step S43, consider In the formula, is the corrected peak shear displacement of the energy anchor; consider In the formula, is the corrected residual shear strength of the energy anchor; Step S44, set Where ξ1 is the model evaluation number corresponding to the peak shear displacement of the energy anchor; make Where ξ2 is the model evaluation number corresponding to the residual shear strength of the energy anchor; Substituting equation (1) and equation (2) into equation (3) and equation (4) respectively, we get: Step S45, consider In the formula, It is a piecewise function of the model evaluation number ξ1 corresponding to the peak shear displacement of the energy anchor and the model evaluation number ξ2 corresponding to the residual shear strength of the energy anchor, which is used to weight the model evaluation number; consider consider Step S46, consider the model evaluation formula: Where ξ is the model evaluation number; Substituting equations (5), (6), (7), (8) and (9) into equation (10), we can obtain the specific result of the model evaluation number ξ. When When the peak shear strength of the energy anchor corresponds to the shear displacement s f1 The main impact is on the anchor-soil interface; Step S5, based on the model evaluation number ξ and the peak shear strength τ of the energy anchor in the curve element f1 , the shear displacement s corresponding to the peak shear strength of the energy anchor f1 and the residual shear strength τ of the energy anchor r1 The relative size relationship between them is used to evaluate the friction resistance of the energy anchor and soil interface.

6. The method according to claim 5, characterized in that Step S5 specifically includes: Step S51, comparing Table 1, obtaining the friction performance evaluation of the interface between the energy anchor and the soil; Table 1 Evaluation table of friction performance between energy anchor and soil interface Step S52, search the following details to obtain a detailed evaluation of the friction performance of the energy anchor and soil interface: a. Comprehensive evaluation: favorable; When τ f1 ≥1.1τ f When the energy anchor rod has a higher peak shear strength than the ordinary anchor rod, it can be judged that: under the current temperature loading condition, the energy device is beneficial to stabilize the anchor-soil interface strength, and the energy anchor rod has a higher ability to resist pull-out shear failure; When f1 ≥1.05s f , τ r1 ≥1.05τ r When ξ>0, the peak shear displacement and residual shear strength of the energy anchor are higher than those of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, the energy device is beneficial to stabilizing the anchor-soil interface. More displacement is required to achieve the same peak shear strength, that is, the displacement safety threshold is higher, and a higher residual shear strength can be maintained after destruction. When f1 ≥1.05s f , 0.95τ r <τ r1 <1.05τ r When ξ>0, the peak shear displacement of the energy anchor is higher than that of the ordinary unit anchor, and the residual shear strength is close to that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, the energy device is beneficial to stabilizing the anchor-soil interface, and more displacement is required to achieve the same peak shear strength, that is, the displacement safety threshold is higher; When 0.95s f f1 <1.05s f , τ r1 ≥1.05τ r When ξ>0, the peak shear strength of the energy anchor is close to that of the common unit anchor, but the residual shear strength is higher than that of the common unit anchor. It can be judged that: under the current temperature loading condition, the energy device is beneficial to stabilizing the anchor-soil interface and improves the residual shear strength of the energy anchor after being destroyed.​ b. Comprehensive evaluation: generally favorable; When f1 ≥1.05s f , τ r1 ≤0.95τ r , ξ>0, that is, the peak shear displacement of the energy anchor is higher than that of the ordinary unit anchor, but the residual shear strength is lower than that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, from the former point of view, the energy device is beneficial to the stabilization of the anchor-soil interface; from the latter point of view, the energy device has a deterioration effect on the stabilization of the anchor-soil interface. At this time, the model evaluation number ξ>0, indicating that the degradation τ r1 The impact is less than the favorable f1 Therefore, the energy device is generally beneficial to stabilizing the anchor-soil interface; When f1 ≤0.95s f , τ r1 ≥1.05τ r , ξ>0, that is, the peak shear displacement of the energy anchor is lower than that of the ordinary unit anchor, but the residual shear strength is higher than that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, from the former point of view, the energy device has a deteriorating effect on stabilizing the anchor-soil interface; from the latter point of view, the energy device is beneficial to stabilizing the anchor-soil interface. At this time, the model evaluation number ξ>0, which means that even if the weighted emphasis is given to s f1 In the case of favorable τ r1 The impact is still greater than the degradation f1 Therefore, the energy device is generally beneficial to stabilizing the anchor-soil interface; When f1 ≥1.05s f , τ r1 ≤0.95τ r , ξ=0, which is a special case, that is, the peak shear displacement of the energy anchor is lower than that of the ordinary unit anchor, but the residual shear strength is higher than that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, the system evaluation number ξ=0, indicating that the degradation τ r1 The degree of influence and benefits f1 The impact is similar, but in order to focus on s f1 ,Therefore, the energy device is generally beneficial to stabilizing the anchor-soil interface; c. Comprehensive evaluation: overall deterioration; When f1 ≥1.05s f , τ r1 ≤0.95τ r , ξ<0, that is, the peak shear displacement of the energy anchor is higher than that of the ordinary unit anchor, but the residual shear strength is lower than that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, from the former point of view, the energy device is beneficial to the stabilization of the anchor-soil interface; from the latter point of view, the energy device has a deterioration effect on the stabilization of the anchor-soil interface. At this time, the system evaluation number ξ<0, indicating that the degradation τ r1 The impact is greater than the positive f1 The degree of influence, therefore, the overall deterioration of the energy device on the stable anchor-soil interface; When f1 ≤0.95s f , τ r1 ≥1.05τ r , ξ<0, that is, the peak shear displacement of the energy anchor is lower than that of the ordinary unit anchor, but the residual shear strength is higher than that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, from the former point of view, the energy device has a deteriorating effect on stabilizing the anchor-soil interface; from the latter point of view, the energy device is beneficial to stabilizing the anchor-soil interface. At this time, the system evaluation number ξ<0, indicating that it is favorable τ r1 The impact is less than the degradation s f1 The degree of influence, therefore, the overall deterioration of the energy device on the stable anchor-soil interface; When f1 ≤0.95s f , τ r1 ≥1.05τ r , ξ=0, which is a special case, that is, the peak shear displacement of the energy anchor is lower than that of the ordinary unit anchor, but the residual shear strength is higher than that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, the system evaluation number ξ=0, indicating that the favorable τ r1 The degree of influence and degradation f1 The impact is similar, but in order to focus on s f1 ,Therefore, the energy device is generally deteriorated for stabilizing the anchor-soil interface; d. Comprehensive evaluation: deterioration; When τ f1 ≤0.9τ f When the energy anchor rod has a lower peak shear strength than the ordinary anchor rod, it can be judged that: under the current temperature loading condition, the energy device has a deteriorating effect on the strength of the anchor-soil interface, and the energy anchor rod has a lower ability to resist pull-out shear failure; When f1 ≤0.95s f , τ r1 ≤0.95τ r When ξ<0, the peak shear displacement and residual shear strength of the energy anchor are lower than those of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, the energy device has a deteriorating effect on the stabilization of the anchor-soil interface. Less displacement is required to achieve the same peak shear strength, that is, the displacement safety threshold is lower, and a lower residual shear strength is maintained after damage. When 0.95s f f1 <1.05s f , τ r1 ≤0.95τ r When ξ<0, the peak shear strength of the energy anchor is close to that of the ordinary unit anchor, but the residual shear strength is lower than that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, the energy device has a deteriorating effect on the stabilization of the anchor-soil interface, which reduces the residual shear strength of the energy anchor after being destroyed.​ When f1 ≤0.95s f , 0.95τ r <τ r1 <1.05τ r When ξ<0, the peak shear displacement of the energy anchor is lower than that of the ordinary unit anchor, and the residual shear strength is close to that of the ordinary unit anchor. It can be judged that: under the current temperature loading condition, the energy device has a deteriorating effect on the stabilization of the anchor-soil interface, and less displacement is required to achieve the same peak shear strength, that is, the displacement safety threshold is lower; e. Comprehensive evaluation: no impact; When 0.95s f f1 <1.05s f , 0.95τ r <τ r1 <1.05τ r When ξ=0, the shear-slip curve of the energy anchor is close to that of the ordinary unit anchor, and the three key curve elements considered are close. It can be judged that under the current temperature loading condition, the energy device has basically no effect on stabilizing or deteriorating the anchor-soil interface.​

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