A static pressure construction method for tunneling large pipe roof

Abstract

The present application discloses a static pressure construction method for a large excavation-type pipe roof, which includes the steps of measuring and positioning, drilling, jacking the pipe roof, and grouting. The drilling is performed using a drilling device, which includes a drilling rig, an excavation device, and a jacking device. The drilling rig is connected to the excavation device and drives the excavation device to rotate. The pipe roof is sleeved outside the excavation device and pressed against the excavation end of the excavation device. The jacking device is connected to the pipe roof and drives the pipe roof to advance with the excavation device. The jacking of the pipe roof and drilling are performed simultaneously. The diameter of the drilled hole is larger than the diameter of the pipe roof. The diameter and shape of the excavation end of the excavation device can be adjusted. When the drilling device advances in a soft soil layer, the shape of the excavation device is adjusted so that the excavation device squeezes the soil layer toward the surrounding area. When encountering hard rock geology, the shape of the excavation device is adjusted so that the excavation device can stably excavate and transport the excavated soil out of the hole. The present application has the effect of reducing the phenomenon of skewed holes in the process of constructing a pipe roof using the follow-pipe drilling method.

Description

Technical Field

[0001] The invention relates to the field of pipe roof construction, in particular to a static pressure construction method for a tunneling type large pipe roof. Background Art

[0002] The pipe-roof method, also known as the umbrella-arch method, is a construction technique used for advance support across a portion or all of a section of an underground project. Essentially, it involves drilling holes above the outer arc of the lining arch ring of an unexcavated underground tunnel or structural project and placing grouting steel pipes for temporary advance support. This prevents soil collapse and surface subsidence, ensuring safe and normal construction of subsequent processes. In shallow, underground excavation, the advance support structure is arranged circumferentially to form a steel pipe-roof protective structure. In short, the pipe-roof technique is designed to ensure safe excavation under unusual geological conditions and to provide a temporary support structure that enhances the bearing capacity of the strata. The pipe-roof technique reinforces and supports the surrounding rock, ensuring safe entry and smooth construction. During construction, a drill is first used to drill the hole, and the pipe-roof is then installed after the hole is fully drilled. Due to the lack of timely support for the hole wall, the hole wall is prone to convergence and deformation, leading to hole collapse.

[0003] Related technologies employ a pipe-following drilling method, using an eccentric drill bit to simultaneously push the pipe roof into the hole during drilling, thereby minimizing the impact of hole wall collapse on pipe roof construction. However, when drilling in hard rock, eccentric drill bits can experience significant deviations, leading to deviations and reduced construction efficiency. Furthermore, hard rock can easily damage eccentric drill bits, shortening their service life.

[0004] With respect to the above-mentioned related technologies, the applicant believes that there are the following defects: when the pipe shed is constructed by following the pipe drilling method, the phenomenon of biased holes is likely to occur. Summary of the Invention

[0005] In order to reduce the phenomenon of skewed holes during the construction of a pipe roof using the method of following the pipe drilling, the present application provides a static pressure construction method for a tunneling type large pipe roof.

[0006] The static pressure construction method of a tunneling large pipe roof provided in this application adopts the following technical solution:

[0007] A tunneling type large pipe roof static pressure construction method comprises the following steps:

[0008] Measurement and positioning: measure the installation position of the pipe roof and mark the installation position of the pipe roof;

[0009] Drilling and jacking the pipe roof: Drilling equipment is used at each marked pipe roof installation location. The drilling equipment includes a drilling rig, a tunneling device and a jacking device. The drilling rig is connected to the tunneling device and drives the tunneling device to rotate. The pipe roof is sleeved outside the tunneling device and pressed against the tunneling end of the tunneling device. The jacking device is connected to the pipe roof and drives the pipe roof to advance with the tunneling device. The jacking of the pipe roof and drilling are carried out simultaneously. The diameter of the drilled hole is larger than the diameter of the pipe roof. The diameter and shape of the tunneling end of the tunneling device can be adjusted. When the drilling equipment advances in soft soil, the shape of the tunneling device is adjusted so that the tunneling device squeezes the soil layer to the surrounding area. When encountering hard rock geology, the shape of the tunneling device is adjusted so that the tunneling device can stably advance and transport the excavated soil out of the hole. After the pipe roof is pushed to the designed depth, drilling is stopped, the tunneling end of the tunneling device is retracted, and the tunneling device is withdrawn from the pipe roof. Finally, the drilling rig, tunneling device and jacking device are dismantled.

[0010] Grouting: Connect the grouting pipe to the pipe shed, and then use pressure grouting to inject reinforcement slurry into the pipe shed.

[0011] By adopting the above technical solution, the diameter of the hole drilled by the drilling equipment is larger than the diameter of the pipe roof, so that the pipe roof can be pushed forward smoothly; when the tunneling device advances in the soft soil layer, it squeezes the soil layer to the surrounding area, making the surrounding soil denser, reducing the collapse of the soil in the soft soil layer around the pipe roof, thereby reducing the friction between the pipe roof and the soil, and facilitating the pushing of the pipe roof; the rotation and pushing forces of the tunneling device are provided separately by the drilling rig and the pushing, and the pushing pressure of the pushing device on the pipe roof is transmitted to the tunneling end of the tunneling device, making it easier for the tunneling device to advance in the soft soil layer, and making the tunneling end of the tunneling device close to the soil in the hard rock geology, so that the tunneling device can maintain a stable forward direction and supplement the forward thrust of the tunneling device, so that the tunneling device can smoothly advance in the hard rock geology and reduce the hole deviation phenomenon.

[0012] Preferably, the excavation device includes a first drill rod, a second drill rod, a third drill rod and a drill bit, the first drill rod is sleeved outside the second drill rod, one end of the second drill rod extends outside the first drill rod, the second drill rod is sleeved outside the third drill rod, the third drill rod is slidably connected to the second drill rod, one end of the third drill rod extends outside the second drill rod, and the drill bit is installed on one end of the first drill rod, the second drill rod and the third drill rod, and the size of the drill bit can be adjusted by adjusting the length of the second drill rod extending outside the first drill rod and the length of the third drill rod extending outside the second drill rod.

[0013] By adopting the above technical solution, the first drill rod, the second drill rod, and the third drill rod are used to connect the drill bit and the drilling rig, and the size of the drill bit is adjusted by the first drill rod, the second drill rod, and the third drill rod, so that the drill bit can adapt to drilling in different geological conditions. After the drilling is completed, the drill bit can be easily withdrawn from the pipe rack by operating the first drill rod, the second drill rod, and the third drill rod.

[0014] Preferably, the drill bit includes a bracket, a plurality of first tunneling plates, a plurality of second tunneling plates, a plurality of side plates and a plurality of end plates. The bracket is installed on one end of the first drill rod, the second drill rod and the third drill rod. The plurality of first tunneling plates are installed on one end of the bracket connected to the third drill rod. The plurality of first tunneling plates can be arranged into a polygonal cone shape. The plurality of second tunneling plates are slidably installed on the side of the first tunneling plate facing the first drill rod. The plurality of second tunneling plates are respectively aligned with the gaps between the plurality of first tunneling plates. The plurality of first tunneling plates are unfolded. During the expansion and contraction process, the second tunneling plate and the first tunneling plate slide relative to each other in the circumferential direction, multiple side plates are respectively installed on the circumference of the bracket, and multiple end plates are respectively installed on one end of the bracket connected to the first drill rod. The gaps between the multiple first tunneling plates, the gaps between the first tunneling plate and the side plate, the gaps between the second tunneling plate and the side plate, the gaps between the multiple second tunneling plates, the gaps between the multiple side plates, the gaps between the side plates and the end plates, and the gaps between the multiple end plates are all sealed with sealing cloth.

[0015] By adopting the above technical solution, when the drill bit advances in soft soil, the length of the third drill rod extending outside the second drill rod is adjusted, so that multiple first tunneling plates can be arranged into a polygonal cone, squeezing the soil around, and improving the stability of the drilled hole; when the drill bit reaches hard soil, the third drill rod is retracted, so that the first tunneling plate and the second tunneling plate are combined into a whole. At this time, the front end of the drill bit becomes a disc shape. Since the force on the drill bit is uniform and axial, the stability of the drill bit in tunneling in hard soil can be improved, and the service life of the drill bit can be extended.

[0016] Preferably, the bracket includes a first connecting sleeve, a second connecting sleeve, a third connecting sleeve, a plurality of first connecting rods, a plurality of second connecting rods, a plurality of third connecting rods, a plurality of first support rods and a plurality of second support rods. The first connecting sleeve is fixedly sleeved outside the first drill rod, the second connecting sleeve is fixedly sleeved outside the end of the second drill rod extending outside the first drill rod, the third connecting sleeve is fixedly sleeved outside the end of the third drill rod extending outside the second drill rod, a plurality of first connecting rods are arranged on the circumference of the first connecting sleeve, one end of the first connecting rod is hinged to the first connecting sleeve, a plurality of third connecting rods are arranged on the circumference of the third connecting sleeve, and one end of the third connecting rod is hinged to the first connecting sleeve. The end is hinged to the third connecting sleeve, the first connecting rod, the second connecting rod and the third connecting rod are hinged in sequence through the hinge shaft, multiple first struts and multiple second struts are arranged on the circumference of the second connecting sleeve, one end of the first strut and one end of the second strut are hinged to each other and hinged to the second connecting sleeve, the other end of the first strut is rotatably connected to the hinge shaft between the second connecting rod and the third connection, the other end of the second strut is rotatably connected to the hinge shaft between the first connecting rod and the second connecting rod, the second strut is capable of extension and contraction, the first excavation plate is fixed to the third connecting rod, the side plate is fixed to the second connecting rod, and the end plate is fixed to the first connecting rod.

[0017] By adopting the above technical solution, by adjusting the length of the second drill rod extending outside the first drill rod, the distance between the first connecting sleeve and the second connecting sleeve can be changed, so that the first connecting rod and the second connecting rod rotate, thereby changing the positions of the first connecting rod and the second connecting rod; by adjusting the length of the third drill rod extending outside the second drill rod, the distance between the third connecting sleeve and the second connecting sleeve can be changed, so that the second connecting rod and the third connecting rod rotate, changing the positions of the second connecting rod and the third connecting rod, thereby realizing the adjustment of the size and shape of the drill bit.

[0018] Preferably, the first drill rod, the second drill rod and the third drill rod are respectively provided with a plurality of bolt holes at one end away from the drill bit, and fixing bolts are installed in the bolt holes, and the fixing bolts limit the displacement of the first drill rod, the second drill rod and the third drill rod.

[0019] By adopting the above technical solution, the fixing bolts pass through the bolt holes of the first drill rod, the second drill rod and the third drill rod respectively, so that the first drill rod, the second drill rod and the third drill rod can be fixed to each other, so that the first drill rod, the second drill rod and the third drill rod can rotate together, driving the drill bit to rotate, and the fixing bolts are pulled out of the bolt holes, so that the axial positions of the first drill rod, the second drill rod and the third drill rod can be adjusted, thereby adjusting the shape and size of the drill bit.

[0020] Preferably, the first excavation plate is provided with a first grouting hole, a grouting valve is installed in the first grouting hole, the side wall of the second drill rod is provided with a second grouting hole arranged along the axial direction, and the first slurry outlet hole and the second slurry outlet hole are connected by a hose; the third drill rod is provided with a slurry outlet hole passing through both ends, and a slurry outlet valve is installed in the slurry outlet hole.

[0021] By adopting the above technical solution, when advancing in soft soil, the grouting valve and the slurry discharge valve are both closed, preventing soil and water in the soft soil from entering the third drill rod and the first grouting hole; when excavating in hard rock, the grouting valve and the slurry discharge valve are both opened, and water columns are sprayed in front of the drill bit through the first grouting hole and the second grouting hole, making it easier for the drill bit to advance in the hard rock and cooling the drill bit; and since the soil density of hard rock is high, it is difficult to squeeze the excavated soil to the surrounding area, and it is easy to cause the drill bit to deviate, and the water sprayed in front of the drill bit drives the excavated soil to be discharged from the third drill rod, which can maintain the smooth excavation of the drill bit in the hard rock.

[0022] Preferably, before measurement and positioning, a concrete guide wall is first cast on the support surface of the tunnel excavation, bolts are embedded in the guide wall, and the installation position of the pipe roof is marked on the guide wall. When drilling, a guide hole is first drilled on the guide wall, and then subsequent drilling and jacking of the pipe roof are carried out.

[0023] By adopting the above technical solution, the forward direction of the pipe roof and the tunneling device can be guided and positioned through the guide wall and the guide hole, which facilitates construction.

[0024] Preferably, the jacking device includes a reaction frame, a jack and a fixing clamp, the reaction frame is installed on the guide wall and fixedly connected to the embedded bolts, the jack is installed on the reaction frame, the jack is connected to the fixing clamp and can drive the fixing clamp to move, and the fixing clamp can fix and clamp the pipe rack.

[0025] By adopting the above technical solution, the fixing clamp is fixedly connected to the pipe shed, and then the pipe shed is driven forward by the force of the jack, and the jacking force can be applied to the drill bit through the pipe shed.

[0026] In summary, this application includes at least one of the following beneficial technical effects:

[0027] 1. The diameter of the hole drilled by the drilling equipment is larger than the diameter of the pipe roof, allowing the pipe roof to be pushed forward smoothly. When the tunneling device advances through the soft soil layer, it squeezes the soil layer toward the surrounding area, making the surrounding soil denser and reducing the collapse of the soft soil layer around the pipe roof. This reduces the friction between the pipe roof and the soil, facilitating the advancement of the pipe roof. The jacking pressure of the jacking device on the pipe roof is transmitted to the tunneling end of the tunneling device, making it easier to advance in soft soil layers. In hard rock, the tunneling end of the tunneling device can press against the soil, thereby maintaining the stability of the tunneling device's forward direction and supplementing the forward thrust of the tunneling device, allowing the tunneling device to advance smoothly in hard rock and reducing hole deviation.

[0028] 2. When the drill bit advances through soft soil, the length of the third drill rod extending beyond the second drill rod is adjusted, allowing the multiple first tunneling plates to form a polygonal cone, squeezing the soil around them and improving the stability of the drilled hole. When the drill bit reaches hard soil, the third drill rod is retracted, allowing the first and second tunneling plates to be combined into a single unit. The front end of the drill bit now becomes disc-shaped. Because the force applied to the drill bit is evenly and axially, it can improve the stability of the drill bit in hard soil and extend the drill bit's service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a flowchart of a tunneling-type large pipe roof static pressure construction method according to an embodiment of the present application.

[0030] Figure 2 It is a schematic structural diagram of the tunneling device in a soft soil layer according to an embodiment of the present application.

[0031] Figure 3 This is a schematic diagram of the structure of the tunneling device in hard rock geology according to an embodiment of the present application.

[0032] Figure 4 It is a schematic structural diagram of the drill bit of an embodiment of the present application.

[0033] Figure 5 It is a schematic diagram of the connection between the first excavation plate and the second excavation plate in an embodiment of the present application.

[0034] Figure 6 It is a schematic structural diagram of the bracket of an embodiment of the present application.

[0035] Description of reference numerals:

[0036] 1. First drill rod; 2. Second drill rod; 3. Third drill rod; 4. Drill bit; 41. Bracket; 411. First connecting sleeve; 412. Second connecting sleeve; 413. Third connecting sleeve; 414. First connecting rod; 415. Second connecting rod; 416. Third connecting rod; 417. First support rod; 418. Second support rod; 42. First excavation plate; 43. Second excavation plate; 44. Side plate; 45. End plate; 46. Sealing cloth; 47. Slide groove; 48. Slider. DETAILED DESCRIPTION

[0037] The following is combined with Figure 1-6 This application is described in further detail.

[0038] The embodiment of the present application discloses a static pressure construction method for a tunneling large pipe roof.

[0039] Reference Figure 1 、 Figure 2 and Figure 3 A tunneling type large pipe roof static pressure construction method comprises the following steps:

[0040] Measurement and positioning: Measure the installation position of the pipe roof on the support surface of the tunnel, and mark and locate the installation position of the pipe roof.

[0041] Drilling and jacking the pipe shed: Drilling equipment is used at each marked pipe shed installation location. The drilling equipment consists of a drilling rig, a tunneling device, and a jacking device. The drilling rig is connected to the tunneling device and drives the tunneling device to rotate. The pipe shed is placed outside the tunneling device and pressed against the tunneling end of the tunneling device. The jacking device is connected to the pipe shed and drives it forward with the tunneling device. The jacking and drilling of the pipe shed are performed simultaneously. The diameter of the drilled hole is larger than that of the pipe shed. The diameter and shape of the tunneling end of the tunneling device are adjustable. When the drilling equipment advances in soft soil, the shape of the tunneling device is adjusted to squeeze the soil inward. When encountering hard rock, the shape of the tunneling device is adjusted to ensure stable excavation and transport the excavated soil out of the hole. When the pipe shed reaches the designed depth, drilling is stopped, the tunneling end of the tunneling device is retracted, and the tunneling device is withdrawn from the pipe shed. Finally, the drilling rig, tunneling device, and jacking device are removed.

[0042] Grouting: Connect the grouting pipe to the pipe shed, and then use pressure grouting to inject reinforcement slurry into the pipe shed.

[0043] Reference Figure 2 and Figure 3The tunneling device includes a first drill rod 1, a second drill rod 2, a third drill rod 3, and a drill bit 4. The first drill rod 1 is sleeved outside the second drill rod 2, which is slidably connected to the first drill rod 1, with one end of the second drill rod 2 extending outside the first drill rod 1. The second drill rod 2 is sleeved outside the third drill rod 3, which is slidably connected to the second drill rod 2, with one end of the third drill rod 3 extending outside the second drill rod 2. The drill bit 4 is mounted on one end of the first drill rod 1, the second drill rod 2, and the third drill rod 3 and is respectively connected to the first drill rod 1, the second drill rod 2, and the third drill rod 3. The size of the drill bit 4 can be adjusted by adjusting the length of the second drill rod 2 extending outside the first drill rod 1 and the length of the third drill rod 3 extending outside the second drill rod 2. The first, second, and third drill rods 1, 2, and 3 are each provided with a plurality of bolt holes at their ends away from the drill bit 4. The bolt holes of the first, second, and third drill rods 1, 2, and 3 are radially aligned, and fixed bolts are installed in the bolt holes. The fixed bolts penetrate the bolt holes of the first, second, and third drill rods 1, 2, and 3 simultaneously, thereby securing the first, second, and third drill rods 1, 2, and 3 to each other and restricting their relative movement. During excavation, the first, second, and third drill rods 1, 2, and 3 can be connected to each other using connectors to extend their length, depending on the excavation depth.

[0044] Reference Figure 4 and Figure 5The drill bit 4 comprises a bracket 41, multiple first excavation plates 42, multiple second excavation plates 43, multiple side plates 44, and multiple end plates 45. The bracket 41 is mounted on one end of the first, second, and third drill rods 1, 2, and 3 and is connected to the front ends of the first, second, and third drill rods 3, respectively. Multiple first excavation plates 42 are mounted on the front end of the bracket 41. The widths of the two ends of the first excavation plates 42 differ, with the end closest to the third drill rod 3 being the smaller end. These multiple first excavation plates 42 can be arranged into a polygonal pyramidal shape, effectively squeezing soil from softer soil layers toward the drill bit 4, reducing the likelihood of soil accumulation near the front of the drill bit 4 and causing soil compaction in front of the drill bit 4. Blades are mounted on the front of the first excavation plates 42 to facilitate excavation in hard rock. The second tunneling plate 43 is mounted behind the first tunneling plate 42. Multiple second tunneling plates 43 align with the gaps between the multiple first tunneling plates 42. Slide grooves 47 are provided at both ends of the rear side of the first tunneling plate 42, running along the width of the first tunneling plate 42. Slide blocks 48 mate with the slide grooves 47 at both ends of the front side of the second tunneling plate 43. The first and second tunneling plates 42, 43 are slidably connected by the slide grooves 47 and the slide blocks 48. A gap exists between the slide blocks 48 and the slide grooves 47, allowing the slide blocks 48 to rotate within the slide grooves 47 to accommodate the required angle change between the first and second tunneling plates 42, 43. During the expansion and contraction of the multiple first tunneling plates 42, the second tunneling plates 43 slide circumferentially relative to the first tunneling plates 42. When the first tunneling plates 42 are expanded, the second tunneling plates 43 close the widening gaps between the first tunneling plates 42. Multiple side plates 44 are mounted around the circumference of the bracket 41, with gaps between adjacent side plates 44. This allows space for the side plates 44 to move closer to the third drill rod 3, thereby reducing the diameter of the drill bit 4. Multiple end plates 45 are mounted at the rear end of the bracket 41, with gaps between adjacent end plates 45, ensuring that the end plates 45 do not interfere with each other during the reduction of the diameter of the drill bit 4. The gaps between multiple first tunneling plates 42, the gaps between the first tunneling plate 42 and the side plate 44, the gaps between the second tunneling plate 43 and the side plate 44, the gaps between multiple second tunneling plates 43, the gaps between multiple side plates 44, the gaps between the side plates 44 and the end plates 45, and the gaps between multiple end plates 45 are all sealed with sealing cloth 46. The sealing cloth 46 is elastic and is made of a high-temperature-resistant and friction-resistant composite rubber material. The sealing cloth 46 seals the gaps outside the drill bit 4, preventing soil from entering the drill bit 4, and reducing the probability of the soil jamming the drill bit 4 and losing the diameter-changing function.

[0045] Reference Figure 6The bracket 41 includes a first connecting sleeve 411, a second connecting sleeve 412, a third connecting sleeve 413, multiple first connecting rods 414, multiple second connecting rods 415, multiple third connecting rods 416, multiple first support rods 417 and multiple second support rods 418. The first connecting sleeve 411 is fixedly sleeved on the outside of the front end of the first drill rod 1, the second connecting sleeve 412 is fixedly sleeved on the outside of the front end of the second drill rod 2, and the third connecting sleeve 413 is fixedly sleeved on the outside of the front end of the third drill rod 3. Multiple first connecting rods 414 are arranged around the first connecting sleeve 411, one end of the first connecting rod 414 is hinged to the first connecting sleeve 411, multiple third connecting rods 416 are arranged around the third connecting sleeve 413, one end of the third connecting rod 416 is hinged to the third connecting sleeve 413, and both ends of the second connecting rod 415 are hinged to one end of the first connecting rod 414 away from the first connecting sleeve 411 and one end of the third connecting rod 416 away from the third connecting sleeve 413 through a hinge shaft respectively, and the second connecting rod 415 is parallel to the first drill pipe 1. Multiple first struts 417 and multiple second struts 418 are arranged around the second connecting sleeve 412. One end of the first strut 417 and one end of the second strut 418 are hinged to each other and to the second connecting sleeve 412. The other end of the first strut 417 is pivotally connected to the hinge axis between the second connecting rod 415 and the third connecting rod 416, while the other end of the second strut 418 is pivotally connected to the hinge axis between the first connecting rod 414 and the second connecting rod 415. The second strut 418 is a gas spring. When the second drill rod 2 retreats to a certain position, the second strut 418 retracts to its minimum length and cannot retract further. At this point, the first strut 417, the second strut 418, and the second connecting rod 415 form a stable triangle, stably supporting the second connecting rod 415. The first excavation plate 42 is fixed to the third connecting rod 416, the side plates 44 are fixed to the second connecting rod 415, and the end plates 45 are fixed to the first connecting rod 414. Each first excavation plate 42 can be fixedly connected to multiple third connecting rods 416, each side plate can be fixedly connected to multiple second connecting rods 415, and each end plate 45 can be fixedly connected to multiple first connecting rods 414, thereby improving the stability of the first excavation plate 42, side plates 44, and end plates 45. The gaps between the first excavation plate 42 and the third connecting sleeve 413, and between the third excavation plate and the first connecting sleeve 411, are sealed by sealing cloth 46. When the third drill rod 3 moves forward relative to the second drill rod 2, it drives the third connecting sleeve 413 forward, causing the third connecting rod 416 to move. The multiple first excavation plates 42 form a polygonal cone, which facilitates squeezing soil in soft soil layers. When the third drill rod 3 moves backward relative to the second drill rod 2, it drives the third connecting sleeve 413 to move backward, driving the third connecting rod 416 to rotate, so that the angle between the multiple first tunneling plates 42 and the third drill rod 3 becomes larger. The multiple first tunneling plates 42 basically form a plane shape, which is beneficial for the drill bit 4 to advance in hard rock geology and is beneficial for maintaining the stability of the direction of tunneling of the drill bit 4 in hard rock geology.When the third drill rod 3 moves forward to the set value relative to the second drill rod 2 and the second drill rod 2 moves forward to the set value relative to the first drill rod 1, the second support rod 418 extends to the maximum value, and the diameter of the drill bit 4 is reduced to be smaller than the diameter of the pipe roof, so that the excavation device can be withdrawn from the pipe roof.

[0046] The first excavation plate 42 is provided with a first grouting hole extending through the excavation plate from front to back, and a grouting valve is installed in each of the first grouting holes. The sidewall of the second drill rod 2 is provided with multiple second grouting holes arranged axially. These second grouting holes are connected to the multiple first grouting holes via hoses, with the ends of the hoses connecting the front and rear ends of the second grouting holes, respectively. The third drill rod 3 is provided with a grouting hole extending through both ends, and a grouting valve is installed in the front end of each grouting hole. When advancing in soft soil, both the grouting valve and the grouting valve are closed, preventing soil and water in the soft soil from entering the third drill rod 3 and the first grouting hole. When advancing in hard rock, both the grouting valve and the grouting valve are opened, and the rear ends of the second grouting holes are connected to a water pump, while the rear ends of the grouting holes are connected to a mud pump. The water pump sprays water through the second and first grouting holes toward the front of the drill bit 4, making it easier for the drill bit 4 to advance in hard rock and reducing its temperature. Moreover, due to the high density of the soil in hard rock geology, it is difficult to squeeze the excavated soil to the surrounding area, and it is easy to cause the drill bit 4 to deviate. The excavated soil is extracted from the third drill rod 3 by a mud pump, which can keep the drill bit 4 advancing smoothly in the hard rock geology.

[0047] Before surveying and positioning, a concrete guide wall is cast on the tunnel excavation support surface. Bolts are pre-embedded in the guide wall. Surveying and positioning are performed within the concrete guide wall. After surveying and positioning, guide holes are drilled in the guide wall to guide the pipe shed. The jacking device includes a reaction frame, a jack, and a retaining clamp. The reaction frame is mounted on the guide wall and fixedly connected to the pre-embedded bolts. The jack is fixed to the reaction frame in the same direction as the pipe shed. The jack is connected to the retaining clamp and can drive the retaining clamp to move, which can securely clamp the pipe shed. The jack applies force to the rear pipe shed from the front. The jack's contraction drives the pipe shed forward, achieving the jacking of the pipe shed. After the jack has contracted to a certain value, the retaining clamp is released, the jack is extended, and the retaining clamp is fixed to the pipe shed. The jack continues to contract, driving the pipe shed forward, and this cycle repeats until the pipe shed is in place. The retaining clamp is a clamp, which is secured to the pipe shed with bolts and nuts. The drilling rig is installed behind the jacking device and applies force to the tunneling device from the rear to the front to avoid interference between the drilling rig and the jacking device.

[0048] The implementation principle of a tunneling type large pipe roof static pressure construction method in an embodiment of the present application is as follows: before drilling, the drill bit 4 is retracted into the pipe roof, and the pipe roof is sleeved outside the first drill rod 1; after entering the soil of the soft soil layer, the drill bit 4 is passed through the pipe roof, and the size of the drill bit 4 is adjusted by the first drill rod 1, the second drill rod 2 and the third drill rod 3, so that the hole drilled by the drill bit 4 is larger than the pipe roof, which is convenient for the jacking of the pipe roof. The drilling rig and the jacking device drive the tunneling device and the pipe roof to continue to move forward. The front end of the pipe roof abuts the rear side of the end plate 45, and the drill bit 4 squeezes the soil around, so that the density of the soil around the pipe roof becomes larger and more solid, reducing the collapse of the surrounding soil during the drilling of the pipe roof, thereby reducing the resistance to the jacking of the pipe roof and facilitating the jacking of the pipe roof. When encountering hard rock, the third drill rod 3 is adjusted backward, causing the first excavation plate 42 at the front of the drill bit 4 to rotate to form a substantially flat surface. The grouting and slurry discharge valves are then opened to discharge the excavated soil, allowing the drill bit 4 to drill more smoothly through the hard rock and reducing the chance of hole deviation. Once the pipe roof is in place, the size of the drill bit 4 is adjusted using the first, second, and third drill rods 1, 2, and 3, so that the hole drilled by the drill bit 4 is smaller than the pipe roof, and the excavation device is withdrawn.

[0049] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A tunneling type large pipe roof static pressure construction method, characterized in that: The steps include: Measurement and positioning: measure the installation position of the pipe roof and mark the installation position of the pipe roof; Drilling and jacking the pipe roof: Drilling equipment is used at each marked pipe roof installation location. The drilling equipment includes a drilling rig, a tunneling device and a jacking device. The drilling rig is connected to the tunneling device and drives the tunneling device to rotate. The pipe roof is sleeved outside the tunneling device and pressed against the tunneling end of the tunneling device. The jacking device is connected to the pipe roof and drives the pipe roof to advance with the tunneling device. The jacking of the pipe roof and drilling are carried out simultaneously. The diameter of the drilled hole is larger than the diameter of the pipe roof. The diameter and shape of the tunneling end of the tunneling device can be adjusted. When the drilling equipment advances in soft soil, the shape of the tunneling device is adjusted so that the tunneling device squeezes the soil layer to the surrounding area. When encountering hard rock geology, the shape of the tunneling device is adjusted so that the tunneling device can stably advance and transport the excavated soil out of the hole. After the pipe roof is pushed to the designed depth, drilling is stopped, the tunneling end of the tunneling device is retracted, and the tunneling device is withdrawn from the pipe roof. Finally, the drilling rig, tunneling device and jacking device are dismantled. Grouting: Connect the grouting pipe to the pipe shed, and then use pressure grouting to inject reinforcement slurry into the pipe shed; The excavation device comprises a first drill rod (1), a second drill rod (2), a third drill rod (3) and a drill bit (4); the first drill rod (1) is sleeved outside the second drill rod (2); one end of the second drill rod (2) extends outside the first drill rod (1); the second drill rod (2) is sleeved outside the third drill rod (3); the third drill rod (3) is slidably connected to the second drill rod (2); one end of the third drill rod (3) extends outside the second drill rod (2); the drill bit (4) is installed on one end of the first drill rod (1), the second drill rod (2) and the third drill rod (3); the size of the drill bit (4) can be adjusted by adjusting the length of the second drill rod (2) extending outside the first drill rod (1) and the length of the third drill rod (3) extending outside the second drill rod (2); The drill bit (4) comprises a bracket (41), a plurality of first excavation plates (42), a plurality of second excavation plates (43), a plurality of side plates (44) and a plurality of end plates (45); the bracket (41) is mounted on one end of the first drill rod (1), the second drill rod (2) and the third drill rod (3); The bracket (41) comprises a first connecting sleeve (411), a second connecting sleeve (412), a third connecting sleeve (413), a plurality of first connecting rods (414), a plurality of second connecting rods (415), a plurality of third connecting rods (416), a plurality of first support rods (417) and a plurality of second support rods (418).

2. The static pressure construction method of a tunneling large pipe roof according to claim 1, characterized in that: The plurality of first tunneling plates (42) are all mounted on one end of the bracket (41) connected to the third drill rod (3); the plurality of first tunneling plates (42) can be arranged to form a polygonal cone; the plurality of second tunneling plates (43) are all slidably mounted on the side of the first tunneling plate (42) facing the first drill rod (1); the plurality of second tunneling plates (43) are respectively aligned with the gaps between the plurality of first tunneling plates (42); during the expansion and contraction of the plurality of first tunneling plates (42), the second tunneling plates (43) and the first tunneling plates (42) slide relative to each other in the circumferential direction; the plurality of side plates (44) The plurality of end plates (45) are respectively installed on the circumference of the bracket (41), and the plurality of end plates (45) are respectively installed on one end of the bracket (41) connected to the first drill rod (1). The gaps between the plurality of first excavation plates (42), the gap between the first excavation plate (42) and the side plate (44), the gap between the second excavation plate (43) and the side plate (44), the gap between the plurality of second excavation plates (43), the gap between the plurality of side plates (44), the gap between the side plate (44) and the end plate (45), and the gaps between the plurality of end plates (45) are all sealed with sealing cloth (46).

3. The static pressure construction method of a tunneling large pipe roof according to claim 2, characterized in that: The first connecting sleeve (411) is fixedly sleeved outside the first drill rod (1), the second connecting sleeve (412) is fixedly sleeved outside one end of the second drill rod (2) extending outside the first drill rod (1), and the third connecting sleeve (413) is fixedly sleeved outside one end of the third drill rod (3) extending outside the second drill rod (2). A plurality of first connecting rods (414) are arranged around the first connecting sleeve (411), one end of the first connecting rod (414) is hinged to the first connecting sleeve (411), and a plurality of third connecting rods (416) are arranged around the third connecting sleeve (413), one end of the third connecting rod (416) is hinged to the third connecting sleeve (413), and the first connecting rod (414), the second connecting rod (415) and the third connecting rod (416) are sequentially connected through The hinge is hinged, and multiple first struts (417) and multiple second struts (418) are all arranged around the second connecting sleeve (412). One end of the first strut (417) and one end of the second strut (418) are hinged to each other and hinged to the second connecting sleeve (412). The other end of the first strut (417) is rotated to connect the hinge between the second connecting rod (415) and the third connection. The other end of the second strut (418) is rotated to connect the hinge between the first connecting rod (414) and the second connecting rod (415). The second strut (418) can be telescopic. The first excavation plate (42) is fixed to the third connecting rod (416), the side plate (44) is fixed to the second connecting rod (415), and the end plate (45) is fixed to the first connecting rod (414).

4. The static pressure construction method of a tunneling large pipe roof according to claim 1, characterized in that: The first drill rod (1), the second drill rod (2) and the third drill rod (3) are respectively provided with a plurality of bolt holes at one end away from the drill bit (4), and fixing bolts are installed in the bolt holes, and the fixing bolts limit the displacement of the first drill rod (1), the second drill rod (2) and the third drill rod (3).

5. The static pressure construction method of a tunneling large pipe roof according to claim 2, characterized in that: The first excavation plate (42) is provided with a first grouting hole, in which a grouting valve is installed; the side wall of the second drill rod (2) is provided with a second grouting hole arranged along the axial direction, and the first grouting hole and the second grouting hole are connected through a hose; the third drill rod (3) is provided with a slurry outlet hole running through both ends, and a slurry outlet valve is installed in the slurry outlet hole.

6. The static pressure construction method of a tunneling large pipe roof according to claim 1, characterized in that: Before measurement and positioning, a concrete guide wall is cast on the support surface of the tunnel excavation. Bolts are embedded in the guide wall, and the installation position of the pipe roof is marked on the guide wall. When drilling, a guide hole is drilled on the guide wall first, and then subsequent drilling and jacking of the pipe roof are carried out.

7. The static pressure construction method of a tunneling large pipe roof according to claim 6, characterized in that: The jacking device includes a reaction frame, a jack and a fixing clamp. The reaction frame is installed on the guide wall and fixedly connected with pre-buried bolts. The jack is installed on the reaction frame. The jack is connected to the fixing clamp and can drive the fixing clamp to move. The fixing clamp can fix and clamp the pipe rack.

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