A method for constructing a jet anchor pre-constructed connecting passage

Abstract

The present application relates to a kind of spray anchor pre-built connecting passage construction method in connecting passage construction technical field, comprising the following steps: in the middle part of the connecting passage position between two tunnels to be built, top into the tool pipe with opening distribution;Rotary jet pile head is drilled into the stratum outside the contour of the connecting passage to be built in tool pipe, and rotary jet pile reinforcement shell is formed;Segmented cutting, discharging and excavating soil layer between rotary jet pile reinforcement shell and tool pipe;And after cutting, discharging and excavating one section, the inner wall of the section of rotary jet pile reinforcement shell is sprayed with fiber concrete to form tunnel permanent structure;Tool pipe is removed;Tunnel permanent structure is trimmed;After toping into tool pipe, rotary jet pile head is inserted outside tool pipe to form rotary jet pile reinforcement shell, then rotary jet pile reinforcement shell and tool pipe are excavated, and fiber concrete is sprayed to form tunnel permanent structure, so that tool pipe can be removed, tool pipe becomes a reusable item, and cost is effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of connecting passage construction technology, and in particular to a method for constructing a precast concrete connecting passage using shotcrete and anchor. Background Technology

[0002] The characteristic of the connecting passage is that after the completion of the two tunnels on the left and right lines, a passage connecting the two tunnels is built using the working faces of the two completed tunnels. It is a human-centered design that allows people to be quickly and safely evacuated to the other tunnel in case of abnormal situations such as fire in one tunnel during normal tunnel operation.

[0003] The earliest construction method for connecting passages involved reinforcing the strata and then excavating using mining methods with composite lining. The reinforcement process was further divided into grouting and freezing methods. This construction method completely exposed the soil during construction. If the soil freezes and the reinforcement fails, or if there are dangerous situations such as quicksand, it is difficult to form effective control measures, which will lead to great danger.

[0004] In recent years, shield tunneling or pipe jacking methods have been used to construct connecting passages in soft soil strata. For example, Chinese patent CN108590695B discloses a shield tunneling construction method and a connecting passage. In this method, the shield shell is gradually assembled and lengthened during the shield tunneling process and is eventually retained in the soil. However, this method is costly and difficult to promote on a large scale.

[0005] To address this, we designed a precast sprayed anchor method for constructing connecting passages. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the present invention discloses a method for constructing a precast sprayed anchor connecting passage.

[0007] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:

[0008] A method for constructing a precast concrete connecting passage includes the following steps:

[0009] Step 1: Using a circular pipe jacking machine, insert a tool pipe with holes throughout into the middle of the planned connecting passage between the two tunnels.

[0010] Step 2: Using jet grouting equipment, the jet grouting pile head is passed through the opening and drilled into the stratum outside the outer contour of the proposed connecting channel to form a jet grouting pile reinforcement shell.

[0011] Step 3: Using jet grouting water cutting and slag removal excavation technology, the soil layer between the jet grouting pile reinforcement shell and the tool pipe is cut and slag removed in sections; and after each section is cut and slag removed, fiber concrete is sprayed onto the inner wall of the jet grouting pile reinforcement shell of that section using a concrete spraying machine to form a permanent tunnel structure.

[0012] Step 4: Remove the tool pipe;

[0013] Step 5: Repair the permanent structure of the tunnel.

[0014] Preferably, the jet grouting equipment drills the jet grouting pile head obliquely into the formation.

[0015] Preferably, the opening in the tool tube body is an oblique hole.

[0016] Preferably, the tool tube end is reinforced to the tunnel wall after step one and before step two.

[0017] Preferably, the tool tube is composed of multiple pipe sections joined together, with adjacent pipe sections connected by built-in bolts.

[0018] Preferably, during the cutting and slag removal excavation process, monitoring equipment is used to monitor whether the jet grouting pile reinforcement shell leaks. If leakage occurs, repair treatment is carried out.

[0019] Preferably, if the equivalent leakage exceeds the specification requirements, the leakage point is located using an endoscope and the jet grouting equipment is used to drill the jet grouting pile head into the stratum corresponding to the leakage point; if the equivalent leakage is less than the specification requirements, air is injected into the excavated cavity to increase pressure.

[0020] Preferably, the segment length is 1.8 to 2.5 meters.

[0021] Preferably, in step two, multiple jet grouting devices are used at intervals along the axial direction of the tool pipe to drill the corresponding jet grouting pile heads into the strata outside the outer contour of the proposed connecting channel.

[0022] By employing the technical solution described above, the present invention has the following beneficial effects:

[0023] 1. After the tool pipe is inserted, the jet grouting pile head is inserted into the tool pipe to form a jet grouting pile reinforcement shell. Then, the space between the jet grouting pile reinforcement shell and the tool pipe is excavated, and fiber-reinforced concrete is sprayed to form a permanent tunnel structure. Therefore, the tool pipe can be removed, making the tool pipe a reusable part, which effectively reduces costs.

[0024] 2. Multiple jet grouting equipment can work simultaneously to construct the jet grouting pile reinforcement shell, effectively accelerating the construction progress of the jet grouting pile reinforcement shell and reducing construction time;

[0025] 3. Simultaneous segmented cutting and slag removal excavation from both ends of the connecting channel can effectively accelerate the construction progress of cutting and slag removal excavation and reduce construction time. Detailed Implementation

[0026] The present invention will be explained in detail through the following embodiments. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention.

[0027] Example 1: A method for constructing a precast concrete connecting passage, comprising the following steps:

[0028] Step 1: Using a circular pipe jacking machine, insert a tool pipe with holes throughout into the middle of the planned connecting passage between the two tunnels.

[0029] As needed, when the distance between two tunnels is large or the distance between two tunnels is greater than the tunnel width, the tool tube can be constructed by connecting multiple tube sections. Adjacent tube sections can be connected by built-in bolts. This ensures that the joints between tube sections are flush, which is beneficial for inserting the tool tube.

[0030] As needed, after the tool pipe is inserted, the ends of the tool pipe are reinforced to the tunnel wall. This is to increase the stability of the tool pipe's position after cutting and excavation, that is, the positions of both ends of the tool pipe are fixed so that the position of the tool pipe will not deviate after cutting and excavation.

[0031] In this example, a 2.6-meter circular pipe jacking machine is used to jack a 2.6-meter diameter tool pipe between two tunnels, allowing the tool pipe to penetrate the soil layer between the two tunnels; that is, the head end of the tool pipe extends out of the soil layer between the two tunnels.

[0032] Step 2: Using jet grouting equipment, the jet grouting pile head is passed through the opening and drilled into the stratum outside the outer contour of the proposed connecting channel to form a jet grouting pile reinforcement shell.

[0033] Furthermore, to increase the stability of the jet grouting pile head position, i.e., the stability of the jet grouting pile reinforcement shell, the jet grouting equipment drills the jet grouting pile head obliquely into the formation. Depending on the requirements, the angle between the jet grouting pile head drilled into the formation and the tool pipe is 30-60 degrees. Depending on the requirements, the opening in the tool pipe is an oblique hole. An oblique hole can be understood as the angle between the central axis of the oblique hole and the central axis of the tool pipe being an acute angle. Depending on the requirements, the opening in the tool pipe can also be a waist-shaped hole, facilitating adjustment of the jet grouting pile head drilling angle according to the actual site conditions.

[0034] To improve construction speed, multiple jet grouting machines are used at intervals along the tool pipe axis to drill the corresponding jet grouting pile heads into the strata outside the outer contour of the proposed connecting passage. In other words, multiple jet grouting machines operate simultaneously within the tool pipe. For example, if the distance between two tunnels is 25 meters (meaning the tool pipe is 25 meters long), a jet grouting machine is placed every 5 meters. Alternatively, all the jet grouting machines can be moved towards the head end of the tool pipe, with one machine placed at 0 meters, 5 meters, 10 meters, 15 meters, and 20 meters from the tail end. This allows five jet grouting machines to operate simultaneously, increasing the construction efficiency of the jet grouting pile reinforcement shell by almost five times compared to using only one machine.

[0035] Step 3: Using jet grouting water cutting and slag removal excavation technology, the soil layer between the jet grouting pile reinforcement shell and the tool pipe is cut and slag removed in sections; after each section is cut and slag removed, fiber concrete is sprayed onto the inner wall of the jet grouting pile reinforcement shell of that section using a concrete spraying machine to form a permanent tunnel structure.

[0036] As needed, a robotic arm controls a water jet pipe to spray water into the soil for excavation. This method of excavation differs from traditional methods and allows for operation in a smaller space.

[0037] To improve construction speed, cutting and slag removal excavation can be carried out simultaneously from both ends of the tool pipe (cutting and slag removal from both ends of the tool pipe toward the middle position). Compared with unidirectional cutting and slag removal excavation (cutting and slag removal from the end of the tool pipe toward its head, or from the head of the tool pipe toward its end), this operation can shorten the cutting and slag removal time by almost half, that is, the construction efficiency can be increased by almost 2 times.

[0038] For example, when the soil layer between the jet grouting pile reinforcement shell and the tool pipe is divided into four sections along the length of the tool pipe, from the head end to the tail end of the tool pipe, these are the first section, the second section, the third section, and the fourth section, respectively. In one embodiment, jet grouting water cutting and slag removal excavation technology is used to cut and remove slag from the soil layer between the first section of the jet grouting pile reinforcement shell and the tool pipe. After the soil layer between the first section of the jet grouting pile reinforcement shell and the tool pipe is cut and slag removed, a concrete spraying machine is used to spray fiber concrete onto the inner wall of the first section of the jet grouting pile reinforcement shell to form a permanent tunnel structure. Then, jet grouting water cutting and slag removal excavation technology is used to cut and remove slag from the soil layer between the second section of the jet grouting pile reinforcement shell and the tool pipe. After the soil layer between the second section of the jet grouting pile reinforcement shell and the tool pipe is cut and slag removed, a concrete spraying machine is used to spray fiber concrete onto the inner wall of the first section of the jet grouting pile reinforcement shell to form a permanent tunnel structure. A shotcrete machine is used to spray fiber-reinforced concrete onto the inner wall of the second section of the jet grouting pile reinforcement shell to form a permanent tunnel structure. Then, a jet grouting water-cooled cutting and slag removal excavation technique is used to cut and remove slag from the soil layer between the third section of the jet grouting pile reinforcement shell and the tool pipe. After the soil layer between the third section of the jet grouting pile reinforcement shell and the tool pipe is cut and slag removed, a shotcrete machine is used to spray fiber-reinforced concrete onto the inner wall of the third section of the jet grouting pile reinforcement shell to form a permanent tunnel structure. Then, a jet grouting water-cooled cutting and slag removal excavation technique is used to cut and remove slag from the soil layer between the fourth section of the jet grouting pile reinforcement shell and the tool pipe. After the soil layer between the fourth section of the jet grouting pile reinforcement shell and the tool pipe is cut and slag removed, a shotcrete machine is used to spray fiber-reinforced concrete onto the inner wall of the fourth section of the jet grouting pile reinforcement shell to form a permanent tunnel structure.

[0039] In one implementation, the process can begin from the fourth segment and end at the first segment, following the same principles of the above-described action steps; further details will not be provided here.

[0040] In one embodiment, a jet grouting water-cooled cutting and slag removal excavation technique is used to cut and remove slag from the soil layer between the first jet grouting pile reinforcement shell and the tool pipe. Simultaneously, another set of equipment uses the same technique to cut and remove slag from the soil layer between the fourth jet grouting pile reinforcement shell and the tool pipe. Then, a shotcrete machine is used to spray fiber-reinforced concrete onto the inner wall of the first jet grouting pile reinforcement shell to form the permanent tunnel structure. Similarly, another shotcrete machine is used to spray fiber-reinforced concrete onto the inner wall of the fourth jet grouting pile reinforcement shell to form the permanent tunnel structure. The tunnel is then constructed using a permanent structure. A jet grouting and clear water cutting and slag removal excavation technique is employed to cut and remove slag from the soil layer between the second jet grouting pile reinforcement shell and the tool pipe. Simultaneously, another set of equipment is used to employ the same technique to cut and remove slag from the soil layer between the third jet grouting pile reinforcement shell and the tool pipe. Then, a shotcrete machine is used to spray fiber-reinforced concrete onto the inner wall of the second jet grouting pile reinforcement shell to form the permanent tunnel structure. Similarly, another shotcrete machine is used to spray fiber-reinforced concrete onto the inner wall of the third jet grouting pile reinforcement shell to form the permanent tunnel structure.

[0041] Preferably, the length of the segment in the segmented cutting and slag removal excavation is set according to the diameter of the connecting channel or the diameter of the tool pipe. Specifically, the length of the segment in the segmented cutting and slag removal excavation is not greater than the diameter of the tool pipe. Preferably, the segment length is 1.8 to 2.5 meters.

[0042] In the example, the length of each segment in the slag removal excavation is 2 meters.

[0043] As needed, during the cutting and slag removal excavation process, monitoring equipment is used to monitor whether the jet grouting pile reinforcement shell leaks. If leakage occurs, repair work is carried out. The monitoring equipment may be an endoscope, depending on the requirements.

[0044] In one embodiment, an endoscope is used to locate the leakage point, and a jet grouting device is used to drill the jet grouting head into the stratum corresponding to the leakage point.

[0045] In another implementation, air is injected into the excavated cavity to increase its pressure. This increased air pressure in the excavated cavity allows mud of different viscosities to be forced back into the formation, thus resolving the leakage problem.

[0046] Depending on the needs, before inflation and pressurization, both ends of the connecting channel can be initially sealed off, and air can be injected into the excavated cavity and the tool pipe; alternatively, the position between the end of the tool pipe and the outer contour of the connecting channel, as well as the opening in the tool pipe body, can be initially sealed off, and air can only be injected into the excavated cavity.

[0047] Preferably, if the equivalent leakage exceeds the specification requirements, the leakage point is located using an endoscope and the jet grouting equipment is used to drill the jet grouting pile head into the stratum corresponding to the leakage point; if the equivalent leakage is less than the specification requirements, air is injected into the excavated cavity to increase pressure.

[0048] Step 4: Remove the tool pipe;

[0049] Step 5: Repair the permanent structure of the tunnel.

[0050] The parts of this invention not described in detail are prior art. It will be apparent to those skilled in the art that this invention is not limited to the details of the above exemplary embodiments, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be regarded as exemplary and non-limiting in all respects, and are intended to fall within the meaning and scope of equivalents.

Claims

1. A method for constructing a precast concrete connecting passage, characterized in that: Includes the following steps: Step 1: Using a circular pipe jacking machine, insert a tool pipe with holes throughout into the middle of the planned connecting passage between the two tunnels. Step 2: Using jet grouting equipment, the jet grouting pile head is passed through the opening and drilled into the stratum outside the outer contour of the proposed connecting channel, forming a jet grouting pile reinforcement shell. The jet grouting equipment drills the jet grouting pile head obliquely into the stratum, with an inclination angle of 30-60 degrees. Step 3: Using jet grouting water cutting and slag removal excavation technology, the soil layer between the jet grouting pile reinforcement shell and the tool pipe is cut and slag removed in sections; and after each section is cut and slag removed, fiber concrete is sprayed onto the inner wall of the jet grouting pile reinforcement shell of that section using a concrete spraying machine to form a permanent tunnel structure. Step 4: Remove the tool pipe; Step 5: Repair the permanent structure of the tunnel.

2. The method for constructing a precast concrete connecting passage according to claim 1, characterized in that: The opening in the tool tube body is an oblique hole.

3. The method for constructing a precast concrete connecting passage according to claim 1, characterized in that: After step one and before step two, the end of the tool tube is reinforced to the tunnel wall.

4. The method for constructing a precast concrete connecting passage according to claim 1, characterized in that: The tool tube is composed of multiple pipe sections joined together, with adjacent pipe sections connected by built-in bolts.

5. The method for constructing a precast sprayed concrete connecting passage according to claim 1, characterized in that: During the cutting and slag removal excavation process, monitoring equipment is used to monitor whether the jet grouting pile reinforcement shell leaks. If leakage occurs, repair treatment is carried out.

6. The method for constructing a precast sprayed concrete connecting passage according to claim 5, characterized in that: If the leakage exceeds the standard requirements, use an endoscope to locate the leakage point and use a jet grouting machine to drill the jet grouting pile head into the stratum corresponding to the leakage point; if the leakage is less than the standard requirements, pressurize the excavated cavity with air.

7. The method for constructing a precast concrete connecting passage according to claim 1, characterized in that: The segment length is 1.8 to 2.5 meters.

8. The method for constructing a precast concrete connecting passage according to claim 1, characterized in that: In step two, multiple jet grouting devices are used at intervals along the axial direction of the tool pipe to drill the corresponding jet grouting pile heads into the strata outside the outer contour of the proposed connecting channel.