阅读说明：本技术 基于盾构作业的钻进锚固预支护系统及施工方法 (Drilling anchoring pre-support system based on shield operation and construction method ) 是由 陈永强 罗标 于 2021-09-28 设计创作，主要内容包括：本发明公开了一种基于盾构作业的钻进锚固预支护系统及施工方法,旨在提供一种钻进锚固预支护系统及基于该系统的施工方法。本发明系统包括MF快换钎杆、钎尾和锚杆；锚杆(1)由与锚固管连接的钎头(1-1)、通过管口锁扣接头与锚固管连接的管靴(1-6)、与该管靴连接的PVC管(1-7)构成；管口锁扣接头由与锚固管连接的锁扣母接头(1-4)、与MF快换钎杆(4)连接的锁扣公接头(1-5)构成,锁扣母接头(1-4)的螺旋通槽(1-4-1)与锁扣公接头(1-5)的螺旋凸轮槽(1-5-1)相适配。本方发明法是先确定掌子面(6)的切割边界(7),将本发明系统倾斜凿入岩体(5),从PVC管(1-7)中退出MF快换钎杆(4),注浆凝固后对掌子面(6)进行切割。(The invention discloses a drilling anchoring pre-support system based on shield operation and a construction method, and aims to provide a drilling anchoring pre-support system and a construction method based on the system. The system comprises an MF quick-change drill rod, a drill shank and an anchor rod; the anchor rod (1) is composed of a drill bit (1-1) connected with the anchoring pipe, a pipe shoe (1-6) connected with the anchoring pipe through a pipe orifice lock joint, and a PVC pipe (1-7) connected with the pipe shoe; the pipe orifice lock buckle joint is composed of a lock catch female joint (1-4) connected with the anchoring pipe and a lock catch male joint (1-5) connected with the MF quick-change drill rod (4), and a spiral through groove (1-4-1) of the lock catch female joint (1-4) is matched with a spiral cam groove (1-5-1) of the lock catch male joint (1-5). The method comprises the steps of firstly determining a cutting boundary (7) of a tunnel face (6), obliquely chiseling the system into a rock body (5), withdrawing the MF quick-change drill rod (4) from the PVC pipes (1-7), and cutting the tunnel face (6) after grouting solidification.)

1. A drilling anchoring pre-support system based on shield operation comprises an anchor rod connected with a drill shank through an MF quick-change drill shank; the method is characterized in that: the anchor rod (1) is composed of an anchoring pipe, a drill bit (1-1) connected to the front end of the anchoring pipe through threads, a pipe boot (1-6) connected to the tail end of the anchoring pipe through a pipe orifice lock joint, and a PVC pipe (1-7) fixedly connected with the pipe boot, wherein a plurality of grouting holes (1-2-3) are distributed on the surface of the anchoring pipe; the pipe orifice lock joint comprises a lock catch female joint (1-4) connected to the tail end of an anchoring pipe through threads and a lock catch male joint (1-5) in threaded connection with an MF quick-change drill rod (4), wherein one end of the lock catch female joint (1-4) is provided with external threads, the other end of the lock catch female joint is provided with a spiral through groove (1-4-1), one end of the lock catch male joint (1-5) is provided with internal threads, the other end of the lock catch female joint is provided with a spiral cam groove (1-5-1), and the spiral through groove (1-4-1) is matched with the spiral cam groove (1-5-1).

2. The shield operation-based drilling anchor pre-support system as claimed in claim 1, wherein: on the lock catch male joint (1-5), a pipe orifice adjacent to the spiral cam groove (1-5-1) is provided with a guide section (1-5-2) which extends along the axial direction and is matched with the inner pipe wall of the lock catch female joint (1-4).

3. The shield operation-based drilling anchor pre-support system as claimed in claim 1, wherein: a pipe orifice at one end of the pipe boot (1-6) is provided with a reducing opening (1-6-1), a pipe orifice at the other end of the pipe boot is provided with a horn-shaped inner conical surface (1-6-2), and a PVC pipe (1-7) is connected with the inner conical surface (1-6-2) through threads; the outer cylindrical surface of the lock catch female joint (1-4) is provided with a clamping groove (1-4-2) matched with the necking (1-6-1), and the pipe boot (1-6) is connected with the clamping groove (1-4-2) of the lock catch female joint (1-4) through the necking (1-6-1).

4. The shield operation-based drilling anchoring pre-support system according to any one of claims 1-3, wherein: the anchoring pipe is formed by butting a plurality of grouting pipes (1-2) with threads at pipe orifices at two ends, and the adjacent grouting pipes (1-2) are connected through threaded pipe joints (1-3); the outer surface of each grouting pipe (1-2) is at least provided with one ring groove (1-2-4), and four grouting holes (1-2-3) which are uniformly distributed on the surface of the ring groove by taking the axial line of the grouting pipe as the center are arranged in each ring groove (1-2-4); the surface of each ring groove (1-2-4) is sleeved with a rubber sleeve (1-2-2) which shields each grouting hole (1-2-3), and the rubber sleeve is compressed by four pressing strips (1-2-1) welded on the grouting pipe (1-2); each pressing strip (1-2-1) and each grouting hole (1-2-3) are arranged in a staggered and spaced mode.

5. A construction method based on the drilling anchoring pre-support system as claimed in any one of claims 1-4, comprising the steps of drilling and grouting; the method is characterized by comprising the following specific steps:

1) the tunnel (8) is divided into a plurality of construction sections along the tunneling direction of the tunnel, and the tunneling depth corresponding to each construction section is L₁、L₂……L_n；

2) Determining a boundary (7) for cutting by a cutter head of the shield machine on a tunnel face (6) corresponding to each construction section;

3) drilling a plurality of the drilling anchoring pre-support systems into a rock body (5) obliquely along the tunneling direction to a designed depth by using a drilling machine; ensuring that the tail ends of the pipe shoes (1-6) are immersed in the rock body (5) outside the boundary (7) and ensuring that the tail ends of the PVC pipes (1-7) are exposed out of the surface of the tunnel face (6) and are positioned in the boundary (7);

4) reversely rotating the drilling machine, driving the locking male joint (1-5) to be separated from the locking female joint (1-4) through the drill shank (3) and the MF quick-change drill rod (4), and then withdrawing the MF quick-change drill rod (4) and the locking male joint (1-5) from the PVC pipe (1-7) through the drill shank (3) by utilizing the drilling machine;

5) injecting slurry into the anchor rod (1) through the PVC pipes (1-7), and then plugging the pipe orifices of the PVC pipes (1-7);

6) after the slurry is solidified, starting a shield machine to cut the tunnel face (6) corresponding to the construction section until the tunneling depth corresponding to the construction section is reached;

7) and (4) retreating the shield tunneling machine for a certain distance, and repeating the operations of the steps 1) to 6) until the whole tunnel (8) is communicated.

Technical Field

The invention relates to a tunnel drilling anchoring pre-support system and a construction method, in particular to a drilling anchoring pre-support system based on shield operation and a construction method based on the drilling anchoring pre-support system.

Background

As is well known, supports for underground works are classified by the construction time of the support structure into pre-supports and post-supports. The support for reinforcing the rock stratum of the tunnel body before the tunnel is excavated is called pre-support, and the support for reinforcing the rock stratum of the tunnel body after the tunnel is excavated is called post-support. The working surface which is continuously pushed forward in the tunnel excavating process is called a tunnel face.

In order to reinforce the rock stratum of the area which is not excavated in front of the tunnel face, prevent the tunnel face from deforming and collapsing and reduce the construction risk, the prior pre-support method based on shield operation is to obliquely drive a plurality of anchors such as anchor rods or anchor cables into the vault and the tunnel walls on two sides of the tunnel in a radial distribution mode on the tunnel face before the shield machine excavates a distance along the excavation direction, and then grout and solidify into the anchor holes. In view of the fact that the method adopts a common anchoring drill bit and a common anchor rod, the method has the following defects:

1) in a complex geological structure with soft rock stratum and granite rock stratum, a common anchoring drill bit is easy to wear and low in drilling efficiency, and cannot meet the anchoring construction requirement;

2) the drill rod is connected with the anchoring drill bit through threads, and when the drill rod needs to be withdrawn after the drilling depth is reached, the drill rod is usually blocked and cannot be withdrawn from the anchoring hole due to impact deformation of the drill rod or the threads meshed with the drill rod. The drill rods are wasted, the anchoring holes are scrapped, and the drill rods retained in the anchoring holes can damage a cutter head of the shield tunneling machine and influence shield operation;

3) the tensile stress needs to be manually adjusted during anchoring, and the operation is relatively troublesome;

4) because the anchor rod is of a metal rod structure, and the tail end of the anchor rod is exposed within the boundary of the tunnel face (such as CN19571959A, CN104989437A, CN109026099A, CN108547291A, CN110985066A, CN112963153A and the like), the damage of the shield tunneling machine cutterhead is easily caused, and the anchor loosening and the anchor quality are affected due to cutting vibration.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a drilling anchoring pre-support system which integrates rock drilling, drilling and anchoring and is based on shield operation.

In order to achieve the aim, the drilling anchoring pre-support system comprises an anchor rod connected with a drill shank through an MF quick-change drill rod; the anchor rod consists of an anchoring pipe, a drill bit, a pipe shoe and a PVC pipe, wherein a plurality of grouting holes are distributed on the surface of the anchoring pipe; the pipe orifice lock joint is composed of a lock catch female joint and a lock catch male joint, the lock catch female joint is in threaded connection with the tail end of the anchoring pipe, the lock catch male joint is in threaded connection with the MF quick-change drill rod, an external thread is arranged at one end of the lock catch female joint, a spiral through groove is formed in the other end of the lock catch female joint, an internal thread is arranged at one end of the lock catch male joint, a spiral cam groove is formed in the other end of the lock catch male joint, and the spiral through groove is matched with the spiral cam groove.

On the public joint of hasp among the above-mentioned technical scheme, the mouth of pipe that is close to spiral cam groove has along the axis direction extension and form the direction section with the inside pipe wall adaptation of hasp female joint.

In the technical scheme, the outer cylindrical surface of the lock catch female joint is provided with a clamping groove; a pipe orifice at one end of the pipe boot is provided with a necking, a pipe orifice at the other end of the pipe boot is provided with a horn-shaped inner conical surface, and the PVC pipe is connected with the inner conical surface through threads; the outer cylindrical surface of the lock catch female joint is provided with a clamping groove matched with the necking, and the pipe boot is connected with the clamping groove of the lock catch female joint through the necking.

In the technical scheme, the anchoring pipe is formed by butting a plurality of grouting pipes with threads at pipe orifices at two ends, and adjacent grouting pipes are connected through threaded pipe joints; the outer surface of each grouting pipe is provided with at least one annular groove, and four grouting holes which are uniformly distributed on the surface of each annular groove by taking the axial line of the grouting pipe as the center are formed in each annular groove; the surface of each ring groove is sleeved with a rubber sleeve which shields each grouting hole, and the rubber sleeve is compressed by four pressing strips welded on the grouting pipe; each pressing strip and each grouting hole are arranged in a staggered and spaced mode.

Another object of the present invention is to provide a construction method based on the drilling anchoring pre-support system.

In order to achieve the purpose, the method provided by the invention comprises the steps of drilling and grouting; the specific operation is as follows:

1) dividing the tunnel into a plurality of construction sections along the tunneling direction of the tunnel, wherein the tunneling depth corresponding to each construction section is L₁、L₂……L_n；

2) Determining the cutting boundary of a cutter head of the shield tunneling machine on the tunnel face corresponding to each construction section;

3) drilling a plurality of drilling anchoring pre-supporting systems into a rock body obliquely along the tunneling direction to a designed depth by using a drilling machine; ensuring that the tail end of the pipe boot is immersed in the rock mass outside the boundary and ensuring that the tail end of the PVC pipe is exposed on the surface of the tunnel face and is positioned in the boundary;

4) reversely rotating the drilling machine, driving the locking male connector and the locking female connector to separate through the drill shank and the MF quick-change drill rod, and then withdrawing the MF quick-change drill rod and the locking male connector from the PVC pipe through the drill shank by using the drilling machine;

5) injecting slurry into the anchor rod through the PVC pipe, and then plugging the pipe orifice of the PVC pipe;

6) after the slurry is solidified, starting a shield machine to cut the tunnel face corresponding to the construction section until the tunneling depth corresponding to the construction section is reached;

7) and (4) retreating the shield tunneling machine for a certain distance, and repeating the operations of the steps 1) to 6) until the whole tunnel is communicated.

Compared with the prior art, the invention has the following advantages:

the rock drilling bit is used for replacing an anchoring bit, so that the rapid rock drilling can be realized even in a complex geological structure environment containing a granite layer, and the drilling efficiency is improved.

One section of grouting pipe or an anchoring pipe formed by butt joint of a plurality of sections of grouting pipes is adopted to replace a drill rod and a traditional anchor rod, so that the drilling system is ensuredStrength; therefore, the two processes of drilling and driving the anchor rod can be combined into a whole, the construction process is effectively simplified, and the construction efficiency is improved.

The pipe orifice lock catch joint composed of the lock catch female joint and the lock catch male joint is adopted to replace the threaded connection between the MF quick-change drill rod and the rock drilling bit, so that the lock catch female joint and the lock catch male joint can be tripped only by reversely rotating the MF quick-change drill rod, and the MF quick-change drill rod can be taken out quickly. The defects that the anchoring hole is scrapped, the drill rod is wasted and the cutter head of the shield machine is damaged due to the fact that the drill rod cannot be taken out are thoroughly avoided.

The surface of the tubular anchor rod is provided with a plurality of annular grooves, and grouting holes are distributed in the annular grooves, so that the grouting holes are filled with slurry in the pipe, the slurry in the pipe can flow out through the grouting holes, the anchoring stability is improved, and the slurry can be poured at fixed points according to rock stratum distribution conditions with different hardness, so that the anchoring quality is improved.

Because the whole section of metal anchoring pipe with the reinforcing steel bar connecting and reinforcing functions is embedded in the rock mass outside the tunnel boundary, the vault and the tunnel wall of the tunnel cannot collapse even if the tunnel is penetrated, and therefore the permanent supporting function is achieved. The PVC pipe obliquely embedded in the construction section is filled with solidified slurry, so that the temporary anchoring and supporting effects on the working face of the construction section are achieved, the PVC pipe and the solidified slurry can be cut and removed by the shield cutter head together with the rock mass of the working face, and the cutter head cannot be damaged; therefore, the operation propulsion of the shield tunneling machine is not influenced.

Drawings

FIG. 1 is a schematic structural view of a drilling anchoring pre-support system provided by the present invention;

FIG. 2 is a schematic illustration of a bolt construction of the drilling anchor pre-support system provided by the present invention;

FIG. 3 is a cross-sectional view A-A of FIG. 2;

FIG. 4 is an enlarged view taken at I in FIG. 2;

FIG. 5 is a schematic illustration of a grout pipe configuration of the drilling anchoring pre-support system provided by the present invention;

FIG. 6 is a schematic perspective view of a locking female joint and a locking male joint of the drilling anchoring pre-support system provided by the invention;

FIG. 7 is a perspective view of a pipe orifice locking joint of the drilling anchoring pre-support system provided by the present invention;

FIG. 8 is a schematic view of a pipe shoe construction of the drilling anchoring pre-support system provided by the present invention;

FIG. 9 is a schematic view of the construction of the anchor rods of the drilling anchoring pre-support system for anchoring and supporting rock mass provided by the present invention;

FIG. 10 is a cross-sectional view B-B of FIG. 9;

FIG. 11 is a cross-sectional view taken at C-C of FIG. 9;

fig. 12 is an enlarged view of the construction of the anchor rods of the drilling anchor pre-support system provided in the present invention for bolting the arch crown.

In the figure: 1 part of anchor rod, 1-1 part of drill bit, 1-2 parts of grouting pipe, 1-2-1 parts of layering, 1-2-2 parts of rubber sleeve, 1-2-3 parts of grouting hole, 1-2-4 parts of ring groove, 1-3 parts of pipe joint, 1-4 parts of lock catch female joint, 1-4-1 parts of spiral through groove, 1-4-2 parts of clamping groove, 1-5 parts of lock catch male joint, 1-5-1 parts of spiral cam groove, 1-5-2 parts of guide section, 1-6 parts of pipe shoe, 1-6-1 parts of necking, 1-6-2 parts of conical surface and 1-7 parts of PVC pipe,

transition pipe joint 2, bore bit 3, MF quick change drill rod 4, rock mass 5, tunnel face 6, boundary 7, tunnel 8.

Detailed Description

The invention is further described with reference to the following figures and specific examples.

As shown in fig. 1 to 8, the drilling anchoring pre-support system provided by the invention is composed of an anchor rod 1 connected with a drill shank 3 through an MF quick-change drill rod 4.

Wherein, the MF quick-change drill rod 4 is a hollow rod-shaped structure with an external thread at one end and an internal thread at the other end; the drill shank 3 is a standard drill tool. The anchor rod 1 is composed of an anchoring pipe, a rock drilling bit 1-1, a pipe shoe 1-6 and a PVC pipe 1-7, wherein a plurality of grouting holes 1-2-3 are distributed on the surface of the anchoring pipe, internal threads are arranged at two ends of the anchoring pipe, the rock drilling bit is connected to the front end of the anchoring pipe through external threads, the pipe shoe is connected with the tail end of the anchoring pipe through a pipe orifice lock joint, and the PVC pipe is fixedly connected with the pipe shoe. The pipe orifice lock joint is composed of a lock catch female joint 1-4 communicated with the tail end of the anchoring pipe through threads and a lock catch male joint 1-5 communicated with the front end of the MF quick-change drill rod 4 through threads; the lock catch female connector 1-4 is a tubular structure with an external thread at one end and a spiral through groove 1-4-1 at the other end, and the lock catch male connector 1-5 is a tubular structure with an internal thread at one end and a spiral cam groove 1-5-1 at the other end; the spiral through groove 1-4-1 is matched with the spiral cam groove 1-5-1.

In order to facilitate the smooth buckling or releasing between the lock catch male connector 1-5 and the lock catch female connector 1-4, a pipe orifice close to the spiral cam groove 1-5-1 on the lock catch male connector 1-5 extends along the axial direction to form a guide section 1-5-2 matched with the inner pipe wall of the lock catch female connector 1-4.

In order to facilitate the connection of the pipe boots 1-6 and the locking female joint 1-4, the outer cylindrical surface of the locking female joint 1-4 is provided with a circular clamping groove 1-4-2, and a pipe orifice at one end of the pipe boot 1-6 is provided with a reducing 1-6-1 matched with the clamping groove. The pipe shoe 1-6 clamps the necking 1-6-1 in the clamping groove 1-4-2 in a press fit mode, and the locking female joint 1-4 and the pipe shoe 1-6 can rotate relatively.

In order to facilitate the PVC pipe 1-7 to be smoothly inserted into and fixedly connected with the pipe boot 1-6, a pipe orifice at the other end of the pipe boot 1-6 is provided with a horn-shaped inner conical surface 1-6-2; the PVC pipes 1-7 are connected with the internal threads distributed on the inner conical surface 1-6-2 through the taper external threads.

In order to facilitate processing, use or transportation, the anchoring pipe is formed by butting a plurality of grouting pipes 1-2 with internal threads at pipe openings at two ends, and the adjacent grouting pipes 1-2 are connected through external thread pipe joints 1-3.

In order to facilitate the filling of the anchoring holes by the slurry and realize fixed-point grouting according to the distribution condition of different rock strata, the outer surface of each grouting pipe 1-2 is provided with at least one annular groove 1-2-4, and four grouting holes 1-2-3 uniformly distributed on the surface of the annular groove by taking the axis of the grouting pipe as the center are arranged in each annular groove 1-2-4.

In order to avoid the leakage of compressed air through the grouting holes 1-2-3 in the drilling process and ensure that the compressed air can smoothly reach the bottom of the drilled hole and blow out rock fragments, the surface of each annular groove 1-2-4 is sleeved with a rubber sleeve 1-2-2 which shields each grouting hole 1-2-3.

In order to avoid friction damage, rollover or wrinkles of the rubber sleeve 1-2-2, four pressing strips 1-2-1 which are welded on the grouting pipe 1-2 and tightly press the rubber sleeve 1-2-2 are arranged on the outer surface of the rubber sleeve, and each pressing strip 1-2-1 and each grouting hole 1-2-3 are arranged in a staggered and spaced mode. The press strip 1-2-1 can play a role in isolating and protecting the rubber sleeve 1-2-2.

It is worth noting that since the grouting pressure is much higher than the pressure of the compressed air, the compressed air can not be released through the grouting hole 1-2-3 to push the rubber sleeve 1-2-2 open during the rock drilling process, so that the compressed air can enter the bottom of the drilling hole through the anchoring pipe and the rock drill bit 1-1 to remove rock debris. In the grouting and anchoring process, the pressure of the concrete slurry is far greater than the pressure of compressed air, so that the concrete slurry can anchor the pipe and the rock drill bit 1-1 to enter the bottom of the anchoring hole to realize anchoring on one hand, and can also push open the rubber sleeve 1-2-2 through the grouting hole 1-2-3 to fill the anchoring hole and permeate the soft rock stratum to realize anchoring on the other hand.

In order to facilitate the MF quick-change drill rod 4 with different specifications to be matched with the drill shank 3, the MF quick-change drill rod 4 is connected with the drill shank 3 through the transition pipe joint 2. One end of the transition pipe joint 2 is provided with an external thread matched with the internal thread of the MF quick-change drill rod 4, and the other end of the transition pipe joint 2 is provided with an internal thread matched with the external thread of the drill shank 3.

The construction method based on the drilling anchoring pre-support system is shown in fig. 9-12, and the technical scheme comprises the steps of drilling and grouting; the specific operation is as follows:

1) according to the geological structure of the rock mass 5, dividing the pre-construction tunnel into a plurality of construction sections along the tunneling direction of the tunnel 8, wherein the tunneling depth corresponding to each construction section is L₁、L₂……L_n；

2) Determining a cutting boundary 7 of a shield machine cutter head on a tunnel face 6 corresponding to each construction section;

3) using the tunnel face 6 as a starting point, and using a drilling machine to obliquely chisel a plurality of drilling anchoring pre-supporting systems into a rock body 5 to a designed depth along the tunneling direction; ensuring that the tail ends of the pipe shoes 1-6 are immersed in the rock mass 5 outside the boundary 7 and ensuring that the tail ends of the PVC pipes 1-7 are exposed on the surface of the tunnel face 6 and are positioned within the boundary 7;

4) reversely rotating the drilling machine, driving the locking male connectors 1-5 and the locking female connectors 1-4 to be separated by the drill shank 3 and the MF quick-change drill rod 4, and then withdrawing the MF quick-change drill rod 4 and the locking male connectors 1-5 from the PVC pipes 1-7 by the drilling machine through the drill shank 3;

5) injecting slurry into the anchor rod 1 through the PVC pipes 1 to 7, and then plugging the pipe orifices of the PVC pipes 1 to 7;

6) after the slurry is solidified, the shield machine is started to cut the tunnel face 6 corresponding to the construction section until the tunneling depth L corresponding to the construction section is reached_n；

7) And (4) retreating the shield tunneling machine for a certain distance, and repeating the operations of the steps 1) to 6) until the whole tunnel 8 is communicated.