[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
[0030] like Figure 1-4 As shown, the embodiment of the present invention provides an anti-seismic and pressure-limiting bolt anchor head, which includes a bolt 1, an annular hydraulic cylinder 4, a damping spring 12 and at least two piston connecting rods 10; the annular hydraulic cylinder 4 is coaxially sleeved on the on the anchor rod 1, and the mounting wall 403 of the annular hydraulic cylinder 4 is connected to the anchor rod 1; the annular hydraulic cylinder 4 is sequentially divided into a first annular cavity from the inside to the outside through the annular partition 8 chamber 401 and a second annular chamber 402; the first annular chamber 401 is provided with a first annular piston 9, and the second annular chamber 402 is provided with a second annular piston 11; each of the piston connecting rods One end of the 10 is connected to the first annular piston 9, and the other end extends out of the annular hydraulic cylinder 4 from one end away from the mounting wall 403 of the annular hydraulic cylinder 4; the second annular piston 11 passes through the damping spring 12 is connected with the end of the second annular chamber 402 away from the installation wall 403 of the annular hydraulic cylinder 4; the end of the first annular chamber 401 away from the piston connecting rod 10 is connected with the second annular chamber One end of the chamber 402 facing away from the damping spring 12 is communicated; a constant pressure valve 7 is installed on the side of the second annular chamber 402 facing away from the damping spring 12 . The mounting wall 403 of the annular hydraulic cylinder 4 of the anti-seismic and pressure-limiting bolt anchor head provided in this embodiment is fixed to the bolt 1 , and one end of the piston connecting rod 10 protrudes out of the annular hydraulic cylinder 4 . Hydraulic oil is injected into the annular cavity 402, and the hydraulic oil flows to the first annular cavity 401 through the connection between the second annular cavity 402 and the first annular cavity 401, so that the piston connecting rod 10 abuts against the rock and soil surface. The flow of viscous liquid and the deformation of the damping spring 12 produce an anti-seismic damping effect, and the constant pressure valve 7 limits the maximum anchoring force, which can prevent the damage of the anchor head caused by the impact load exceeding the bearing capacity of the anchor rod.
[0031] like figure 1 As shown, when the reinforced rock and soil mass vibrates and displaces outward, the first annular piston 9 is pushed through the backing ring 13 and its piston connecting rod 10 to displace, the pressure in the annular hydraulic cylinder 4 increases, and the hydraulic oil passes through the first annular piston 9. The communication hole between the chamber 401 and the second annular chamber 402 flows from the first annular chamber 401 to the second annular chamber 402 to generate a viscous damping effect, thereby pushing the second annular piston 11 to displace and compress the damping spring 12 to achieve buffering Purpose: When the reinforced rock and soil is vibrated and displaced inward, the pressure in the annular hydraulic cylinder 4 is reduced, the damping spring 12 pushes the second annular piston 11 to displace, maintains the pressure in the cylinder, and pushes the first annular piston 9 to displace inward. , so that the piston connecting rod 10 and its backing ring 13 maintain the necessary pressure with the rock and soil mass to achieve the purpose of buffering. In this embodiment, the pressure in the hydraulic cylinder can be calculated by the deformation amount and the damping spring stiffness, so as to solve the problem that the nonlinear relationship between the anchoring force and the deformation, the anchoring force and the displacement is not clear, and it is convenient for calculation and analysis.
[0032] Further, each of the piston connecting rods 10 is evenly distributed along the circumferential direction of the anchor rod 1, and can accept vibration changes at multiple points in this area.
[0033] Further, one end of the second annular chamber 402 close to the installation wall 403 of the annular hydraulic cylinder 4 is communicated with the liquid inlet pipe 5 , and the liquid inlet pipe 5 is provided with a liquid inlet valve 6 .
[0034] further, as figure 1 As shown, one end of the second annular chamber 402 close to the installation wall 403 of the annular hydraulic cylinder 4 is provided with a constant pressure hole, and a constant pressure valve 7 is installed on the constant pressure hole. Common constant pressure valves 7 such as safety valves, relief valves, pressure reducing valves, sequence valves or pressure control valves belong to the prior art. The maximum anchoring force during the vibration process can be controlled by the constant pressure valve 7 to prevent the impact load from damaging the anchor head.
[0035] further, as figure 1 As shown, a backing ring 13 is sleeved on the anchor rod 1 , and one end of each of the piston connecting rods 10 extending out of the annular hydraulic cylinder 4 is connected with the backing ring 13 . The piston rod 10 is in contact with the anchored rock and soil through the backing ring 13 .
[0036] further, as figure 1 As shown, a nut 2 is threadedly connected to the anchor rod 1 , and one side of the nut 2 is fixed to the mounting wall 403 of the annular hydraulic cylinder 4 . Further, a backing plate 3 is arranged between the nut 2 and the annular hydraulic cylinder 4, the backing plate 3 is sleeved on the anchor rod 1, and one side of the backing plate 3 is connected to the nut 2 is connected, and the other side is connected with the installation wall 403 of the annular hydraulic cylinder 4 . When the displacement value of the anti-seismic and compression-limiting anchor head of the present embodiment reaches the maximum range, the measurement can be repeated by adjusting the positions of the nut 2 and the backing plate 3 and reinstalling, and the range is not limited.
[0037] Further, there is a gap between the outer wall of the anchor rod 1 and the side wall of the annular hydraulic cylinder 4 on the side close to the anchor rod 1 .
[0038] further, as figure 1 As shown, the piston connecting rod 10 is provided with a scale along the length direction of the piston connecting rod 10 . The piston connecting rod 10 in this embodiment has a scale, which can measure the displacement value of the anchored rock and soil mass after vibration, so as to measure the deformation displacement value of the rock and soil mass, which is convenient for design calculation and analysis, and is simple and convenient.
[0039] The seismic-resistance and compression-limiting anchor bolt head of this embodiment overcomes the unclear relationship between the anchoring force and the deformation of the traditional compression anchor, the displacement value is limited, the deformation and displacement value of the rock and soil mass cannot be measured, the installation requirements of the compression rod body are high, and the Repeated use, high cost and many disadvantages.
[0040] like Figure 1-4 As shown, this embodiment also provides a specific implementation method for the above-mentioned seismic and compression-limiting anchor bolt head:
[0041] (1) After the construction of the anchor rod 1 is completed, a sufficient exposed length is reserved according to the estimated deformation of the rock and soil mass, and the exposed part is processed into a thread shape and passes through the circular hole in the middle of the annular hydraulic cylinder 4;
[0042] (2) Rotate the anchor bolt head so that the constant pressure hole connected with the constant pressure valve 7 is at the highest position;
[0043] (3) Press the gasket 13 of the anti-seismic pressure-limiting anchor bolt head close to the surface of the rock and soil mass (the surface of the rock and soil mass should be smoothed with high-grade cement mortar, or a pad with a larger area is preset), and the annular hydraulic cylinder 4 is moved. Make the scale of the piston connecting rod 10 relative to the mounting wall 403 of the annular hydraulic cylinder 4 at the zero scale position;
[0044] (4) Install the nut backing plate 3 and tighten the nut 2;
[0045] (5) Open the liquid inlet valve 6, inject viscous hydraulic oil from the liquid inlet pipe 5 with the hydraulic pump, when the hydraulic oil fills the annular hydraulic cylinder 4 (about to overflow from the constant pressure hole), screw on and tighten the constant pressure valve 7 ;
[0046] (6) Continue to press in the hydraulic oil, push the piston connecting rod 10 of the annular hydraulic cylinder 4, and tighten the anchor rod 1 until the hydraulic oil discharged from the constant pressure valve 7 contains no air bubbles, and the hydraulic oil can be recovered by a liquid bag;
[0047] (7) Adjust the pressure in the hydraulic cylinder through the hydraulic pump, so that the prestress of the anchor rod 1 meets the design requirements;
[0048] (8) Close the liquid inlet valve 6, and record the scale value of the piston connecting rod 10 relative to the installation wall 403 of the annular hydraulic cylinder 4 at this time. The scale value is the initial scale value (should be a negative value);
[0049] (9) After the vibration occurs, observe the displacement of the piston connecting rod 10 relative to the installation wall 403 of the annular hydraulic cylinder 4 in time (it can be measured regularly), and when it is close to the maximum scale value, record the scale value (positive value) at this time. The difference between the scale value and the initial scale value is the deformation and displacement value of the rock and soil mass;
[0050] (10) Connect the hydraulic pump, open the inlet valve 6, and gradually reduce the pressure to zero;
[0051] (11) Unscrew the constant pressure valve 7;
[0052] (12) Adjust the positions of the nut 2 and the backing plate 3 so that the scale of the piston connecting rod 10 relative to the mounting wall 403 of the annular hydraulic cylinder 4 is at the zero scale position;
[0053] (13) Repeat the work from (4) to (12) until the deformation of the rock and soil mass basically ends;
[0054] (14) Remove the anchor head of the anti-seismic and pressure-limiting anchor;
[0055] (15) Install the ordinary bolt anchor head or simply let the pressure ring anchor head (the ordinary bolt anchor head can also be preset by presetting the backing plate under the gasket and the nut between the gasket 13 and the installation wall 403 in advance, The prestress can be applied by tightening the nut before removing the seismic pressure limiting anchor);
[0056] (16) Accumulate the displacement value obtained by a single measurement, that is, the total deformation displacement value of the rock and soil mass, and draw a displacement-time curve.
[0057] The above steps are the construction steps of the bolt support project in the soft rock large deformation tunnel, which can not only prevent the damage to the anchor head caused by the vibration generated by the tunnel blasting construction, but also meet the requirements of the large deformation of the soft rock. For seismic fortification projects in high-intensity areas, (1)~(8) can be implemented after the bolt construction is completed, and steps (9)~(13) and (16) can be implemented after the earthquake occurs, and the slope surface caused by the earthquake can be obtained. displacement value.
[0058] like figure 1 As shown, the anti-seismic and pressure-limiting anchor bolt head provided in this embodiment is a hydraulic-spring structure, which is suitable for anti-seismic slopes in high-intensity areas and during the construction of high-stress soft rock large-deformation tunnels. When in use, the piston connecting rod 10 is placed at the zero-scale position relative to the installation wall 403 of the annular hydraulic cylinder 4; after opening the liquid inlet valve 6, the hydraulic pump is used to inject hydraulic oil into the annular hydraulic cylinder 4 from the liquid inlet pipe 5. When the oil is full of the annular hydraulic cylinder 4, install the constant pressure valve 7 (make sure the constant pressure valve interface is at the top during installation), continue to inject hydraulic oil into the annular hydraulic cylinder 4, and push the installation of the piston connecting rod 10 relative to the annular hydraulic cylinder 4 The wall 403 is displaced, the anchor rod 1 is tightened, and the damping spring 12 is in a pressurized state; when the pressure in the annular hydraulic cylinder 4 exceeds the allowable pressure of the constant pressure valve 7, the damping spring 12 is close to the pressure-bearing limit state at this time, a little Residual gas and hydraulic oil flow out from the pressure relief hole of the constant pressure valve; when the outflowing hydraulic oil does not contain air bubbles, adjust the pressure in the annular hydraulic cylinder 4 through the hydraulic pump to make the anchor rod 1 meet the design prestress requirements, and record this time The scale value (negative value) of the piston connecting rod at the position of the installation wall 403 of the annular hydraulic cylinder 4, which is the initial scale value.
[0059] By adjusting the area ratio of the first annular chamber 401 and the second annular chamber 402, the stiffness and deformation requirements of the damping spring 12 can be effectively reduced; once the pressure in the annular hydraulic cylinder 4 exceeds the allowable value of the constant pressure valve 7, the hydraulic pressure The oil flows out from the decompression hole of the constant pressure valve 7 until the piston connecting rod 10 reaches the maximum scale value relative to the wall of the annular hydraulic cylinder 4, and the scale value at this time is recorded. The difference between the scale value and the initial scale value is the rock and soil The deformation displacement value of the body.
[0060] After completing a measurement process, open the constant pressure valve 7 to reduce pressure, adjust the position of the nut 2 and the backing plate 3, and re-pressurize to start a new measurement process. As long as the exposed bolt 1 has a sufficient length, the deformation of the rock and soil mass can be adjusted by adjusting the position of the seismic and compression-limiting bolt head several times. Restricted, the sum of the displacement values obtained from multiple measurements is the total displacement value of the rock and soil mass.
[0061] After the deformation or displacement is basically over, the seismic-resistance and compression-limiting anchor bolt head can be disassembled, and the ordinary anchor head or the simple pressure ring anchor head can be used instead, so as to achieve the effect of repeated use and low cost.
[0062] In this embodiment, after the deformation of the rock and soil mass is stabilized, directly use the nut 2 and the nut backing plate 3 to fix the bolt 1 on the surface of the rock and soil mass (by pre-setting the nut backing plate and the middle of the piston backing ring under the backing ring) Pre-loaded nuts to apply prestress), and then remove the seismic compression-limiting anchor bolt head; when there is still a small amount of residual deformation in the rock and soil, you can also remove the seismic compression-limiting bolt anchor head, and replace it with a simple pressure ring anchor head , the residual deformation at this time is very small, so that the pressure ring can meet the deformation requirements of the rock and soil mass.
[0063] The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the present invention. within the scope of protection.
