Construction method for horizontal jet grouting pile advance support crossing water-rich sandstone section surrounding rock tunnel

Abstract

The invention discloses a construction method for a horizontal jet grouting pile advance support to penetrate through a water-rich sandstone section surrounding rock tunnel. The construction method comprises the following steps that a, construction preparation is conducted, specifically, construction drawings and geological data are familiar, a construction scheme is determined, materials, equipment and tools needed by construction are prepared, and a construction site is cleaned and leveled; and b, measuring and positioning according to the design axis and mileage of the tunnel. The method has the beneficial effects that the stability of surrounding rock is improved, a curtain body can be formed on the periphery of the tunnel to bear part of stratum pressure, the stability of sandy soil soft rock after excavation is kept, and vault slump, collapse and ground surface settlement are effectively controlled; the degree of mechanization is high, equipment matching is perfect, for example, a pst-60 horizontal rotary spraying drilling machine and the like are adopted, the construction efficiency is improved, and the construction safety risk is reduced; and safety guarantee is provided for tunnel excavation, and the possibility of dangerous conditions such as collapse and collapse in the construction process is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel construction, in particular to a construction method for a horizontal jet grouting pile advanced support tunnel that passes through a surrounding rock section of a water-rich sandstone section. Background Art

[0002] The structure of the tunnel consists of two parts: the main building and ancillary equipment. The main building consists of a tunnel body and a tunnel portal. The ancillary equipment includes a car shelter, fire-fighting facilities, emergency communications and drainage facilities. Long tunnels also have special ventilation and lighting equipment. The horizontal jet jet pile advance support method for crossing the water-rich sandstone surrounding rock tunnel is used for tunnel construction.

[0003] However, the existing horizontal rotary jet grouting pile advance support construction method for crossing the water-rich sandstone section surrounding rock tunnel has some defects in use, such as not having the advantages of ensuring construction safety, flexible adjustment, wide application range and high construction precision. This makes the horizontal rotary jet grouting pile advance support construction method for crossing the water-rich sandstone section surrounding rock tunnel have limitations in use and cannot meet the needs of the current market. Due to the above problems, a horizontal rotary jet grouting pile advance support construction method for crossing the water-rich sandstone section surrounding rock tunnel is specifically introduced. Summary of the invention

[0004] The purpose of the present invention is to provide a construction method for a horizontal jet grouting pile advance support through a water-rich sandstone surrounding rock tunnel, which has the advantages of ensuring construction safety, flexible adjustment, wide application range and high construction accuracy.

[0005] To achieve the above object, the present invention provides the following technical solution: a construction method for a horizontal jet grouting pile advance support through a water-rich sandstone surrounding rock tunnel, comprising the following steps:

[0006] Step a: Construction preparation: including familiarizing yourself with the construction drawings and geological data, determining the construction plan, preparing the materials, equipment and tools required for construction, and cleaning and leveling the construction site;

[0007] Step b: Measurement and positioning: Based on the designed axis and mileage of the tunnel, use high-precision measuring instruments such as total stations to accurately measure and determine the plane position of the horizontal jet grouting piles and the inclination angle of the pile body, and mark the position of each horizontal jet grouting pile on the tunnel face to provide a clear guide for the drilling operation;

[0008] Step c: Drilling rig in place: Move the jet grouting rig to the predetermined position and adjust the horizontal and vertical degrees of the rig;

[0009] Step d: Drilling: Use a suitable drill bit to drill holes. During the drilling process, pay attention to controlling the drilling speed and direction to ensure the accuracy and quality of the drilling;

[0010] Step e: Inserting the pipe: After the drilling is completed, insert the jet pipe into the hole to the designed depth;

[0011] Step f: Rotary grouting: Start the rotary grouting equipment and perform rotary grouting according to the set parameters such as pressure, flow rate and rotation speed to fully mix the slurry with the soil;

[0012] Step g: Slurry preparation: According to the design requirements, the rotary spray slurry is prepared strictly according to the mix ratio to ensure that the performance of the slurry meets the construction requirements;

[0013] Step h: lifting the jet spray pipe: during the jet spraying process, the jet spray pipe is lifted at a constant speed to ensure the molding quality of the jet spray pile;

[0014] Step i: Cleaning equipment: After completing the jet grouting operation, clean the jet grouting equipment in time to prepare for the next construction;

[0015] Step j: Quality inspection: Carry out quality inspection on the completed horizontal jet grouting piles, including the strength, diameter, length and other indicators of the pile body, to ensure that they meet the design requirements;

[0016] Step k: Tunnel excavation: After the horizontal jet grouting pile advance support reaches the design strength, the tunnel excavation construction is carried out. During the excavation process, the deformation of the surrounding rock should be closely observed and corresponding support measures should be taken in time.

[0017] Preferably, the specific steps of construction preparation in step a include being familiar with relevant materials such as construction drawings and geological survey reports, fully understanding the design requirements and geological conditions of the tunnel project, formulating a detailed construction plan, including construction technology, construction process, quality control measures, safety measures, etc., preparing materials required for construction, such as cement, admixtures, etc., ensuring that the quality and quantity of materials meet the construction requirements, deploying and inspecting mechanical equipment required for construction, such as rotary jet drilling rigs, high-pressure grouting pumps, mixers, etc., ensuring that the equipment performs well and operates normally, cleaning and leveling the construction site, building construction access roads, ensuring the access and working conditions of the construction site, and building temporary facilities required for construction, such as material storage, duty rooms, etc.

[0018] Preferably, the specific steps of putting the drilling rig in place in step c include moving the jet grouting drill rig to a predetermined construction position, ensuring the horizontality of the body and the verticality of the drill rod by adjusting the legs and jacks of the drill rig, aligning the drill bit of the drill rig with the pre-marked pile position center, and controlling the error within an allowable range.

[0019] Preferably, the specific steps of drilling in step d include starting a drilling rig, the model of the drilling rig is a pst-60 horizontal rotary jet drilling rig, using a suitable drilling process and drill bit, drilling according to the designed angle and depth, and during the drilling process, closely observing the drilling conditions, including drilling speed, torque, slag discharge, etc., adjusting the drilling parameters in time to ensure the quality and verticality of the borehole, and recording various data during the drilling process, such as drilling depth, formation changes, etc., to provide a reference for subsequent construction.

[0020] Preferably, the specific steps of inserting the pipe in step e include cleaning and inspecting the borehole after the drilling is completed to ensure that there is no debris or hole collapse in the hole, inserting the pre-processed rotary jet pipe into the hole until the designed depth is reached, and paying attention to protecting the pipe body during the insertion of the rotary jet pipe to avoid collision and damage.

[0021] Preferably, the specific steps of the rotary grouting operation in step f include starting a high-pressure grouting pump, starting the rotary grouting operation according to pre-set parameters such as pressure, flow and rotation speed, and spraying the slurry through the nozzle of the rotary grouting pipe at high speed. At the same time, the rotary grouting pipe is rotated and lifted to fully mix the slurry with the soil to form a horizontal rotary grouting pile, controlling the pressure and flow of the rotary grouting to ensure that the slurry can effectively reinforce the soil, closely observing the pressure changes and slurry bubbling during the rotary grouting process, and timely adjusting the construction parameters.

[0022] Preferably, the specific steps of preparing the slurry in step g include accurately measuring the amounts of cement, water and admixtures according to the slurry mix ratio required by the design, first adding water into the mixer, then slowly adding cement and admixtures, and fully stirring to ensure that the performance of the slurry meets the construction requirements, and performing quality inspection on the prepared slurry, including indicators such as the density, fluidity, and setting time of the slurry.

[0023] Preferably, the specific step of lifting the rotary spraying pipe in step h includes lifting the rotary spraying pipe at a constant speed during the rotary spraying operation, and the lifting speed must match the injection volume and rotation speed of the slurry to ensure that the pile body of the rotary spraying pile is uniform and continuous without broken piles and shrinkage.

[0024] Preferably, the specific steps of cleaning the equipment in step i include immediately stopping the operation of the grouting pump and the drilling rig after the rotary jetting operation is completed, and thoroughly cleaning the high-pressure grouting pump, rotary jet pipe, mixer and other equipment with clean water to prevent slurry residue from clogging the equipment.

[0025] Preferably, the specific steps of quality inspection in step j include using methods such as coring by drilling, standard penetration test, static load test, etc. to conduct quality inspection on the completed horizontal jet grouting piles, detecting the strength, diameter, length, integrity and other indicators of the pile body, judging whether it meets the design requirements, and taking measures such as pile replenishment to deal with the pile bodies that fail the inspection. The specific steps of tunnel excavation in step k include carrying out tunnel excavation construction after the horizontal jet grouting pile advance support reaches the design strength, adopting appropriate excavation methods, such as the step method, the circular excavation and reserved core soil method, etc., and strictly controlling the excavation advance. During the excavation process, closely observe the deformation of the surrounding rock, and promptly carry out initial support, such as erecting steel arch frames and shotcrete.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] Improve the stability of surrounding rock: a curtain body can be formed around the tunnel to bear part of the stratum pressure, maintain the stability of sandy soft rock after excavation, and effectively control the sliding and collapse of the arch and surface settlement;

[0028] High degree of mechanization: complete equipment, such as the use of pst-60 horizontal jet jet drilling rig, which improves construction efficiency and reduces construction safety risks;

[0029] Ensure construction safety: Provide safety for tunnel excavation and reduce the possibility of dangerous situations such as landslides and collapses during construction;

[0030] The pile quality is good: by controlling the appropriate pressure and speed, the cut sand and soil can be fully mixed with the slurry to form a uniform horizontal columnar cement sand consolidation body, which plays a reinforcing and supporting role;

[0031] Flexible adjustment: According to the different geological conditions of the surrounding rock, the size of the jet grouting consolidation body can be reduced, the injection pressure and pumping volume can be appropriately increased, the rotation and lifting speed can be reduced, or multiple jetting and mixing measures can be adopted;

[0032] Good water-proofing effect on water-rich strata: It can effectively prevent surface subsidence caused by tunnel excavation and ensure the safety of surface pipelines, buildings and road traffic;

[0033] Wide application scope: It can be applied to a variety of complex geological conditions, especially in the construction of tunnels with special geology and soft surrounding rocks;

[0034] High construction accuracy: The pst-60 horizontal jet grouting machine is equipped with a depth and accuracy measuring instrument, which can measure the drilling depth and verticality of the borehole at any time to ensure the accuracy and sensitivity of the drilling;

[0035] Small impact on the surrounding environment: Compared with some other reinforcement methods, such as open excavation, the damage to the surface environment is relatively small. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] Example 1

[0038] A construction method for a horizontal jet grouting pile advance support through a water-rich sandstone surrounding rock tunnel comprises the following steps:

[0039] Step a: Construction preparation: including familiarizing yourself with the construction drawings and geological data, determining the construction plan, preparing the materials, equipment and tools required for construction, and cleaning and leveling the construction site;

[0040] Step b: Measurement and positioning: Based on the designed axis and mileage of the tunnel, use high-precision measuring instruments such as total stations to accurately measure and determine the plane position of the horizontal jet grouting piles and the inclination angle of the pile body, and mark the position of each horizontal jet grouting pile on the tunnel face to provide a clear guide for the drilling operation;

[0041] Step c: Drilling rig in place: Move the jet grouting rig to the predetermined position and adjust the horizontal and vertical degrees of the rig;

[0042] Step d: Drilling: Use a suitable drill bit to drill holes. During the drilling process, pay attention to controlling the drilling speed and direction to ensure the accuracy and quality of the drilling;

[0043] Step e: Inserting the pipe: After the drilling is completed, insert the jet pipe into the hole to the designed depth;

[0044] Step f: Rotary grouting: Start the rotary grouting equipment and perform rotary grouting according to the set parameters such as pressure, flow rate and rotation speed to fully mix the slurry with the soil;

[0045] Step g: Slurry preparation: According to the design requirements, the rotary spray slurry is prepared strictly according to the mix ratio to ensure that the performance of the slurry meets the construction requirements;

[0046] Step h: lifting the jet spray pipe: during the jet spraying process, the jet spray pipe is lifted at a constant speed to ensure the molding quality of the jet spray pile;

[0047] Step i: Cleaning equipment: After completing the jet grouting operation, clean the jet grouting equipment in time to prepare for the next construction;

[0048] Step j: Quality inspection: Carry out quality inspection on the completed horizontal jet grouting piles, including the strength, diameter, length and other indicators of the pile body, to ensure that they meet the design requirements;

[0049] Step k: Tunnel excavation: After the horizontal jet grouting pile advance support reaches the design strength, the tunnel excavation construction is carried out. During the excavation process, the deformation of the surrounding rock should be closely observed and corresponding support measures should be taken in time.

[0050] Example 2

[0051] In Example 1, the following steps are added:

[0052] The specific steps of construction preparation in step a include being familiar with relevant materials such as construction drawings and geological survey reports, fully understanding the design requirements and geological conditions of the tunnel project, formulating a detailed construction plan, including construction technology, construction process, quality control measures, safety measures, etc., preparing materials required for construction, such as cement, admixtures, etc., ensuring that the quality and quantity of materials meet the construction requirements, allocating and inspecting mechanical equipment required for construction, such as jet grouting drills, high-pressure grouting pumps, mixers, etc., ensuring that the equipment has good performance and operates normally, cleaning and leveling the construction site, building construction access roads, ensuring the access and working conditions of the construction site, and building temporary facilities required for construction, such as material storage, duty room, etc. The specific steps of putting the drilling rig in place in step c include moving the jet grouting drill rig to the predetermined construction position, ensuring the horizontality of the body and the verticality of the drill rod by adjusting the legs and jacks of the drilling rig, and aligning the drill bit of the drilling rig with the center of the pre-marked pile position, with the error controlled within the allowable range.

[0053] A construction method for a horizontal jet grouting pile advance support through a water-rich sandstone surrounding rock tunnel comprises the following steps:

[0054] Step a: Construction preparation: including familiarizing yourself with the construction drawings and geological data, determining the construction plan, preparing the materials, equipment and tools required for construction, and cleaning and leveling the construction site;

[0055] Step b: Measurement and positioning: Based on the designed axis and mileage of the tunnel, use high-precision measuring instruments such as total stations to accurately measure and determine the plane position of the horizontal jet grouting piles and the inclination angle of the pile body, and mark the position of each horizontal jet grouting pile on the tunnel face to provide a clear guide for the drilling operation;

[0056] Step c: Drilling rig in place: Move the jet grouting rig to the predetermined position and adjust the horizontal and vertical degrees of the rig;

[0057] Step d: Drilling: Use a suitable drill bit to drill holes. During the drilling process, pay attention to controlling the drilling speed and direction to ensure the accuracy and quality of the drilling;

[0058] Step e: Inserting the pipe: After the drilling is completed, insert the jet pipe into the hole to the designed depth;

[0059] Step f: Rotary grouting: Start the rotary grouting equipment and perform rotary grouting according to the set parameters such as pressure, flow rate and rotation speed to fully mix the slurry with the soil;

[0060] Step g: Slurry preparation: According to the design requirements, the rotary spray slurry is prepared strictly according to the mix ratio to ensure that the performance of the slurry meets the construction requirements;

[0061] Step h: lifting the jet spray pipe: during the jet spraying process, the jet spray pipe is lifted at a constant speed to ensure the molding quality of the jet spray pile;

[0062] Step i: Cleaning equipment: After completing the jet grouting operation, clean the jet grouting equipment in time to prepare for the next construction;

[0063] Step j: Quality inspection: Carry out quality inspection on the completed horizontal jet grouting piles, including the strength, diameter, length and other indicators of the pile body, to ensure that they meet the design requirements;

[0064] Step k: Tunnel excavation: After the horizontal jet grouting pile advance support reaches the design strength, the tunnel excavation construction is carried out. During the excavation process, the deformation of the surrounding rock should be closely observed and corresponding support measures should be taken in time.

[0065] Example 3

[0066] In Example 2, the following steps are added:

[0067] The specific steps of drilling in step d include starting the drilling rig, the model of the drilling rig is a pst-60 horizontal rotary jet drilling rig, using appropriate drilling technology and drill bits, drilling according to the designed angle and depth, closely observing the drilling conditions during the drilling process, including drilling speed, torque, slag removal, etc., adjusting the drilling parameters in time to ensure the quality and verticality of the drilling, and recording various data during the drilling process, such as drilling depth, formation changes, etc., to provide a reference for subsequent construction. The specific steps of inserting the pipe in step e include cleaning and inspecting the borehole after the drilling is completed to ensure that there is no debris and collapse in the hole, inserting the pre-processed rotary jet pipe into the hole until it reaches the designed depth, and paying attention to protecting the pipe body during the insertion of the rotary jet pipe to avoid collision and damage.

[0068] A construction method for a horizontal jet grouting pile advance support through a water-rich sandstone surrounding rock tunnel comprises the following steps:

[0069] Step a: Construction preparation: including familiarizing yourself with the construction drawings and geological data, determining the construction plan, preparing the materials, equipment and tools required for construction, and cleaning and leveling the construction site;

[0070] Step b: Measurement and positioning: Based on the designed axis and mileage of the tunnel, use high-precision measuring instruments such as total stations to accurately measure and determine the plane position of the horizontal jet grouting piles and the inclination angle of the pile body, and mark the position of each horizontal jet grouting pile on the tunnel face to provide a clear guide for the drilling operation;

[0071] Step c: Drilling rig in place: Move the jet grouting rig to the predetermined position and adjust the horizontal and vertical degrees of the rig;

[0072] Step d: Drilling: Use a suitable drill bit to drill holes. During the drilling process, pay attention to controlling the drilling speed and direction to ensure the accuracy and quality of the drilling;

[0073] Step e: Inserting the pipe: After the drilling is completed, insert the jet pipe into the hole to the designed depth;

[0074] Step f: Rotary grouting: Start the rotary grouting equipment and perform rotary grouting according to the set parameters such as pressure, flow rate and rotation speed to fully mix the slurry with the soil;

[0075] Step g: Slurry preparation: According to the design requirements, the rotary spray slurry is prepared strictly according to the mix ratio to ensure that the performance of the slurry meets the construction requirements;

[0076] Step h: lifting the jet spray pipe: during the jet spraying process, the jet spray pipe is lifted at a constant speed to ensure the molding quality of the jet spray pile;

[0077] Step i: Cleaning equipment: After completing the jet grouting operation, clean the jet grouting equipment in time to prepare for the next construction;

[0078] Step j: Quality inspection: Carry out quality inspection on the completed horizontal jet grouting piles, including the strength, diameter, length and other indicators of the pile body, to ensure that they meet the design requirements;

[0079] Step k: Tunnel excavation: After the horizontal jet grouting pile advance support reaches the design strength, the tunnel excavation construction is carried out. During the excavation process, the deformation of the surrounding rock should be closely observed and corresponding support measures should be taken in time.

[0080] Example 4

[0081] In Example 3, the following steps are added:

[0082] The specific steps of the rotary jetting operation in step f include starting the high-pressure grouting pump, starting the rotary jetting operation according to the pre-set parameters such as pressure, flow and rotation speed, the slurry is ejected at high speed through the nozzle of the rotary jet pipe, and the rotary jet pipe is rotated and lifted at the same time to fully mix the slurry and the soil to form a horizontal rotary jet pile, and the pressure and flow of the rotary jet are controlled to ensure that the slurry can effectively reinforce the soil, and the pressure changes and slurry bubbling during the rotary jetting process are closely observed to adjust the construction parameters in time. The specific steps of the slurry preparation in step g include accurately measuring the amount of cement, water and admixture according to the slurry mix ratio required by the design, first adding water to the mixer, and then slowly adding cement and admixture, and fully mixing to ensure that the performance of the slurry meets the construction requirements, and the prepared slurry is quality tested, including the density, fluidity, setting time and other indicators of the slurry.

[0083] A construction method for a horizontal jet grouting pile advance support through a water-rich sandstone surrounding rock tunnel comprises the following steps:

[0084] Step a: Construction preparation: including familiarizing yourself with the construction drawings and geological data, determining the construction plan, preparing the materials, equipment and tools required for construction, and cleaning and leveling the construction site;

[0085] Step b: Measurement and positioning: Based on the designed axis and mileage of the tunnel, use high-precision measuring instruments such as total stations to accurately measure and determine the plane position of the horizontal jet grouting piles and the inclination angle of the pile body, and mark the position of each horizontal jet grouting pile on the tunnel face to provide a clear guide for the drilling operation;

[0086] Step c: Drilling rig in place: Move the jet grouting rig to the predetermined position and adjust the horizontal and vertical degrees of the rig;

[0087] Step d: Drilling: Use a suitable drill bit to drill holes. During the drilling process, pay attention to controlling the drilling speed and direction to ensure the accuracy and quality of the drilling;

[0088] Step e: Inserting the pipe: After the drilling is completed, insert the jet pipe into the hole to the designed depth;

[0089] Step f: Rotary grouting: Start the rotary grouting equipment and perform rotary grouting according to the set parameters such as pressure, flow rate and rotation speed to fully mix the slurry with the soil;

[0090] Step g: Slurry preparation: According to the design requirements, the rotary spray slurry is prepared strictly according to the mix ratio to ensure that the performance of the slurry meets the construction requirements;

[0091] Step h: lifting the jet spray pipe: during the jet spraying process, the jet spray pipe is lifted at a constant speed to ensure the molding quality of the jet spray pile;

[0092] Step i: Cleaning equipment: After completing the jet grouting operation, clean the jet grouting equipment in time to prepare for the next construction;

[0093] Step j: Quality inspection: Carry out quality inspection on the completed horizontal jet grouting piles, including the strength, diameter, length and other indicators of the pile body, to ensure that they meet the design requirements;

[0094] Step k: Tunnel excavation: After the horizontal jet grouting pile advance support reaches the design strength, the tunnel excavation construction is carried out. During the excavation process, the deformation of the surrounding rock should be closely observed and corresponding support measures should be taken in time.

[0095] Example 5

[0096] In Example 4, the following steps are added:

[0097] The specific steps of lifting the rotary jet pipe in step h include uniformly lifting the rotary jet pipe at a certain speed during the rotary jet operation, and the lifting speed must match the injection amount and rotation speed of the slurry to ensure that the pile body of the rotary jet pile is uniform and continuous without broken piles and shrinkage. The specific steps of cleaning the equipment in step i include immediately stopping the operation of the grouting pump and the drilling rig after completing the rotary jet operation, and thoroughly cleaning the high-pressure grouting pump, rotary jet pipe, mixer and other equipment with clean water to prevent slurry residue from clogging the equipment.

[0098] A construction method for a horizontal jet grouting pile advance support through a water-rich sandstone surrounding rock tunnel comprises the following steps:

[0099] Step a: Construction preparation: including familiarizing yourself with the construction drawings and geological data, determining the construction plan, preparing the materials, equipment and tools required for construction, and cleaning and leveling the construction site;

[0100] Step b: Measurement and positioning: Based on the designed axis and mileage of the tunnel, use high-precision measuring instruments such as total stations to accurately measure and determine the plane position of the horizontal jet grouting piles and the inclination angle of the pile body, and mark the position of each horizontal jet grouting pile on the tunnel face to provide a clear guide for the drilling operation;

[0101] Step c: Drilling rig in place: Move the jet grouting rig to the predetermined position and adjust the horizontal and vertical degrees of the rig;

[0102] Step d: Drilling: Use a suitable drill bit to drill holes. During the drilling process, pay attention to controlling the drilling speed and direction to ensure the accuracy and quality of the drilling;

[0103] Step e: Inserting the pipe: After the drilling is completed, insert the jet pipe into the hole to the designed depth;

[0104] Step f: Rotary grouting: Start the rotary grouting equipment and perform rotary grouting according to the set parameters such as pressure, flow rate and rotation speed to fully mix the slurry with the soil;

[0105] Step g: Slurry preparation: According to the design requirements, the rotary spray slurry is prepared strictly according to the mix ratio to ensure that the performance of the slurry meets the construction requirements;

[0106] Step h: lifting the jet spray pipe: during the jet spraying process, the jet spray pipe is lifted at a constant speed to ensure the molding quality of the jet spray pile;

[0107] Step i: Cleaning equipment: After completing the jet grouting operation, clean the jet grouting equipment in time to prepare for the next construction;

[0108] Step j: Quality inspection: Carry out quality inspection on the completed horizontal jet grouting piles, including the strength, diameter, length and other indicators of the pile body, to ensure that they meet the design requirements;

[0109] Step k: Tunnel excavation: After the horizontal jet grouting pile advance support reaches the design strength, the tunnel excavation construction is carried out. During the excavation process, the deformation of the surrounding rock should be closely observed and corresponding support measures should be taken in time.

[0110] Example 6

[0111] In Example 5, the following steps are added:

[0112] The specific steps of quality inspection in step j include using methods such as coring by drilling, standard penetration test, static load test, etc. to conduct quality inspection on the completed horizontal jet grouting piles, inspecting the strength, diameter, length, integrity and other indicators of the pile body, judging whether it meets the design requirements, and taking measures such as pile replenishment to deal with the pile body that fails the inspection. The specific steps of tunnel excavation in step k include excavating the tunnel after the horizontal jet grouting pile advance support reaches the design strength, using appropriate excavation methods, such as the step method, the circular excavation and reserved core soil method, etc., and strictly controlling the excavation advance. During the excavation process, closely observe the deformation of the surrounding rock, and promptly carry out initial support, such as erecting steel arch frames and shotcrete.

[0113] A construction method for a horizontal jet grouting pile advance support through a water-rich sandstone surrounding rock tunnel comprises the following steps:

[0114] Step a: Construction preparation: including familiarizing yourself with the construction drawings and geological data, determining the construction plan, preparing the materials, equipment and tools required for construction, and cleaning and leveling the construction site;

[0115] Step b: Measurement and positioning: Based on the designed axis and mileage of the tunnel, use high-precision measuring instruments such as total stations to accurately measure and determine the plane position of the horizontal jet grouting piles and the inclination angle of the pile body, and mark the position of each horizontal jet grouting pile on the tunnel face to provide a clear guide for the drilling operation;

[0116] Step c: Drilling rig in place: Move the jet grouting rig to the predetermined position and adjust the horizontal and vertical degrees of the rig;

[0117] Step d: Drilling: Use a suitable drill bit to drill holes. During the drilling process, pay attention to controlling the drilling speed and direction to ensure the accuracy and quality of the drilling;

[0118] Step e: Inserting the pipe: After the drilling is completed, insert the jet pipe into the hole to the designed depth;

[0119] Step f: Rotary grouting: Start the rotary grouting equipment and perform rotary grouting according to the set parameters such as pressure, flow rate and rotation speed to fully mix the slurry with the soil;

[0120] Step g: Slurry preparation: According to the design requirements, the rotary spray slurry is prepared strictly according to the mix ratio to ensure that the performance of the slurry meets the construction requirements;

[0121] Step h: lifting the jet spray pipe: during the jet spraying process, the jet spray pipe is lifted at a constant speed to ensure the molding quality of the jet spray pile;

[0122] Step i: Cleaning equipment: After completing the jet grouting operation, clean the jet grouting equipment in time to prepare for the next construction;

[0123] Step j: Quality inspection: Carry out quality inspection on the completed horizontal jet grouting piles, including the strength, diameter, length and other indicators of the pile body, to ensure that they meet the design requirements;

[0124] Step k: Tunnel excavation: After the horizontal jet grouting pile advance support reaches the design strength, the tunnel excavation construction is carried out. During the excavation process, the deformation of the surrounding rock should be closely observed and corresponding support measures should be taken in time.

[0125] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A construction method for a horizontal jet grouting pile advanced support through a water-rich sandstone surrounding rock tunnel, characterized in that: The following steps are involved: Step a: Construction preparation: including familiarizing yourself with the construction drawings and geological data, determining the construction plan, preparing the materials, equipment and tools required for construction, and cleaning and leveling the construction site; Step b: Measurement and positioning: Based on the designed axis and mileage of the tunnel, use high-precision measuring instruments such as total stations to accurately measure and determine the plane position of the horizontal jet grouting piles and the inclination angle of the pile body, and mark the position of each horizontal jet grouting pile on the tunnel face to provide a clear guide for the drilling operation; Step c: Drilling rig in place: Move the jet grouting rig to the predetermined position and adjust the horizontal and vertical degrees of the rig; Step d: Drilling: Use a suitable drill bit to drill holes. During the drilling process, pay attention to controlling the drilling speed and direction to ensure the accuracy and quality of the drilling; Step e: Insertion: After drilling is completed, insert the jet pipe into the hole to the designed depth; Step f: Rotary grouting: Start the rotary grouting equipment and perform rotary grouting according to the set parameters such as pressure, flow rate and rotation speed to fully mix the slurry with the soil; Step g: Slurry preparation: According to the design requirements, the rotary spray slurry is prepared strictly according to the mix ratio to ensure that the performance of the slurry meets the construction requirements; Step h: lifting the jet spray pipe: during the jet spraying process, the jet spray pipe is lifted at a constant speed to ensure the molding quality of the jet spray pile; Step i: Cleaning equipment: After completing the jet grouting operation, clean the jet grouting equipment in time to prepare for the next construction; Step j: Quality inspection: Carry out quality inspection on the completed horizontal jet grouting piles, including the strength, diameter, length and other indicators of the pile body, to ensure that they meet the design requirements; Step k: Tunnel excavation: After the horizontal jet grouting pile advance support reaches the design strength, the tunnel excavation construction is carried out. During the excavation process, the deformation of the surrounding rock should be closely observed and corresponding support measures should be taken in time.

2. The method for constructing a tunnel with horizontal jet grouting piles for advanced support through a water-rich sandstone surrounding rock section according to claim 1, characterized in that: The specific steps of construction preparation in step a include being familiar with relevant materials such as construction drawings and geological survey reports, fully understanding the design requirements and geological conditions of the tunnel project, formulating a detailed construction plan, including construction technology, construction process, quality control measures, safety measures, etc., preparing materials required for construction, such as cement, admixtures, etc., ensuring that the quality and quantity of materials meet the construction requirements, allocating and inspecting mechanical equipment required for construction, such as rotary jet drilling rigs, high-pressure grouting pumps, mixers, etc., ensuring that the equipment has good performance and operates normally, cleaning and leveling the construction site, building construction access roads, ensuring the access and working conditions of the construction site, and building temporary facilities required for construction, such as material warehouses, duty rooms, etc.

3. The method for constructing a tunnel with horizontal jet grouting piles for advanced support through a water-rich sandstone surrounding rock section according to claim 1, characterized in that: The specific steps of positioning the drilling rig in step c include moving the jet grouting drilling rig to a predetermined construction position, adjusting the drilling rig's legs and jacks to ensure the horizontality of the body and the verticality of the drill rod, aligning the drilling rig's drill bit with the pre-marked pile position center, and controlling the error within an allowable range.

4. The method for constructing a tunnel with horizontal jet grouting piles for advanced support through a water-rich sandstone surrounding rock section according to claim 1, characterized in that: The specific steps of drilling in step d include starting the drilling rig, the model of the drilling rig is a pst-60 horizontal rotary jet drilling rig, using a suitable drilling process and drill bit, drilling according to the designed angle and depth, and during the drilling process, closely observing the drilling conditions, including drilling speed, torque, slag discharge, etc., and adjusting the drilling parameters in time to ensure the quality and verticality of the drilling, and recording various data during the drilling process, such as drilling depth, formation changes, etc., to provide a reference for subsequent construction.

5. The method for constructing a tunnel with horizontal jet grouting piles for advanced support through a water-rich sandstone surrounding rock section according to claim 1, characterized in that: The specific steps of inserting the pipe in step e include cleaning and inspecting the borehole after the drilling is completed to ensure that there is no debris or hole collapse in the hole, inserting the pre-processed rotary jet pipe into the hole until it reaches the designed depth, and paying attention to protecting the pipe body during the insertion of the rotary jet pipe to avoid collision and damage.

6. The method for constructing a tunnel with horizontal jet grouting piles for advanced support through a water-rich sandstone surrounding rock section according to claim 1, characterized in that: The specific steps of the rotary jetting operation in step f include starting the high-pressure grouting pump, starting the rotary jetting operation according to pre-set parameters such as pressure, flow and rotation speed, and spraying the slurry at high speed through the nozzle of the rotary jetting pipe. At the same time, the rotary jetting pipe is rotated and lifted to fully mix the slurry with the soil to form a horizontal rotary jetting pile, and the pressure and flow of the rotary jetting are controlled to ensure that the slurry can effectively reinforce the soil. The pressure changes and slurry bubbling during the rotary jetting process are closely observed to adjust the construction parameters in time.

7. The method for constructing a tunnel with horizontal jet grouting piles for advanced support through a water-rich sandstone surrounding rock section according to claim 1, characterized in that: The specific steps of preparing the slurry in step g include accurately measuring the amounts of cement, water and admixtures according to the slurry mix ratio required by the design, first adding water into the mixer, then slowly adding cement and admixtures, and fully stirring to ensure that the performance of the slurry meets the construction requirements, and performing quality inspection on the prepared slurry, including indicators such as the density, fluidity, and setting time of the slurry.

8. The method for constructing a tunnel with horizontal jet grouting piles for advanced support through a water-rich sandstone surrounding rock section according to claim 1, characterized in that: The specific step of lifting the rotary jet pipe in step h includes lifting the rotary jet pipe at a certain speed during the rotary jet operation, and the lifting speed must match the injection amount and rotation speed of the slurry to ensure that the pile body of the rotary jet pile is uniform and continuous without broken piles and shrinkage.

9. The method for constructing a tunnel with horizontal jet grouting piles for advanced support through a water-rich sandstone surrounding rock section according to claim 1, characterized in that: The specific steps of cleaning the equipment in step i include immediately stopping the operation of the grouting pump and the drilling rig after the rotary jetting operation is completed, and thoroughly cleaning the high-pressure grouting pump, rotary jetting pipe, mixer and other equipment with clean water to prevent slurry residue from clogging the equipment.

10. The method for constructing a tunnel with horizontal jet grouting piles for advanced support through a water-rich sandstone surrounding rock section according to claim 1, characterized in that: The specific steps of quality inspection in step j include using methods such as coring by drilling, standard penetration test, static load test, etc. to conduct quality inspection on the completed horizontal jet grouting piles, inspecting the strength, diameter, length, integrity and other indicators of the pile body, judging whether it meets the design requirements, and taking measures such as pile replenishment to deal with the pile body that fails the inspection. The specific steps of tunnel excavation in step k include excavating the tunnel after the horizontal jet grouting pile advance support reaches the design strength, using appropriate excavation methods such as the step method, the circular excavation and reserved core soil method, etc., and strictly controlling the excavation advance. During the excavation process, closely observe the deformation of the surrounding rock, and promptly carry out initial support, such as erecting steel arch frames and shotcrete.