CN115726792A - Basement rock and boulder pretreatment method for large-section rectangular jacking pipe - Google Patents
Basement rock and boulder pretreatment method for large-section rectangular jacking pipe Download PDFInfo
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- CN115726792A CN115726792A CN202211478651.2A CN202211478651A CN115726792A CN 115726792 A CN115726792 A CN 115726792A CN 202211478651 A CN202211478651 A CN 202211478651A CN 115726792 A CN115726792 A CN 115726792A
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Abstract
The invention discloses a bedrock and boulder pretreatment method for a large-section rectangular jacking pipe, which at least comprises the following steps: and (5) crushing the rock and pressing mud to retreat by the miniature jacking pipe. The micro pipe jacking rock crushing at least comprises the step of constructing a pretreatment hole opening wall; installing a water stopping device; jacking a miniature jacking pipe, loading the pipe, crushing rock, deslagging and jacking to a preset length; the mud pressing and returning at least comprises preparing composite thick daub; injecting composite thick cement gum to the front of the miniature push bench in the hole to squeeze and fill formation gaps and generate certain counter force to form an overpressure closed environment; the pipe withdrawing frictional resistance is resisted by the mud pressing counter force and the pulling force together, so that the steel pipe and the miniature pipe jacking machine are easy to be pulled back under the action of the pulling device, and mud pressing and pulling back are synchronous; and (4) completely filling the pre-treatment holes with the composite thick cement, withdrawing the miniature push bench, sealing the holes, and completing the pre-treatment of the current holes. The method effectively replaces the rock stratum into the processing stratum which can adapt to cutting tunneling of the rectangular pipe jacking machine, and has the advantages of large construction coverage, safety, high efficiency and controllable sedimentation.
Description
Technical Field
The invention relates to the technical field of underground engineering construction, in particular to a method for pretreating bedrock and boulder of a large-section rectangular jacking pipe.
Background
With the continuous development of economic society and the acceleration of urbanization process in China, the problems of traffic jam, difficult parking, insufficient station layout, land resource shortage, high ground removal cost and the like in the built urban area are gradually highlighted due to the fact that early planning is not in place and the urban economy is not estimated sufficiently. The urban underground space is developed by a mechanical rectangular pipe jacking underground excavation construction technology which is green, safe, efficient and low in comprehensive cost, and the technology becomes a key method for solving the problems.
The mechanical rectangular pipe jacking subsurface excavation construction technology is suitable for geology from soft clay to gravel soil, such as silt, silt clay, cohesive soil, silt, gravel soil (silt-gravel sand), gravel soil, soft rock (less than 5 MPa) and the like. According to the manufacturing technology and construction experience of the existing domestic rectangular pipe jacking equipment, the rectangular pipe jacking equipment cannot be used for normal jacking construction under geological conditions of strong-medium induced liquefaction rock strata, boulders and the like with high rock saturated uniaxial compressive strength. At present, when a rectangular jacking pipe meets a bed rock stratum, the rock in the crossing range of the section of the jacking pipe can be crushed in advance before jacking construction, wherein in the prior art, a horizontal jumbolter is adopted to drill through hard rock intruding into a jacking pipe tunnel, and a method of filling mud pressing slurry is adopted to perform hard rock treatment after the excavation diameter of a cutter head of the jacking pipe machine is enlarged, but the method has the following problems: (1) The construction length of the horizontal anchor rod drilling machine is limited, the construction precision cannot be guaranteed when the length exceeds 30m, the hole channeling is easy to occur and the posture is difficult to control as the strength of weathered rocks is higher, and the situation that the posture floats upwards or the hole channeling is serious when boulder corners are met is serious, so that the pretreatment effect cannot be completely achieved; (2) The sand soil rich in underground water exists in the cross section range, and the method is easy to cause stratum loss and cause ground settlement during pretreatment construction; (3) The larger the section of the rectangular jacking pipe is, the more the horizontal anchor rod drilling holes are arranged, the tedious construction is carried out, and the construction period is long. Furthermore, bedrock or boulders between the "honeycomb" like horizontal cell lattices cannot be handled; (4) The diameter of a cutter head of the rectangular pipe jacking machine needs to be enlarged after the horizontal anchor rod is preprocessed, and the cost is additionally increased. If the rectangular push pipe meets protruding geology of bedrock in the jacking process, the rectangular push pipe machine needs to be retreated and then rebuilt and the cutter head needs to be enlarged, so that the large-section rectangular push pipe machine is large in retreating construction risk and high in cost, and the method has no cost advantage on the whole.
Therefore, the invention provides a bedrock and boulder pretreatment method which has strong adaptability to rock stratums, large pretreatment coverage area, high precision, simple construction process, high speed, small disturbance to the stratums, safer construction, controllable sedimentation and low comprehensive cost.
Disclosure of Invention
The invention provides a bedrock and boulder pretreatment method for a large-section rectangular jacking pipe, which aims to solve the technical problems of low overall bedrock treatment precision, incomplete pretreatment, weak stratum adaptability, long construction period and complexity in the prior art.
In order to solve the technical problem, an embodiment of the present invention provides a method for pre-treating bedrock and boulder of a large-section rectangular jacking pipe, which at least includes:
crushing the miniature jacking pipe rock and pressing mud to retreat;
wherein, miniature pipe jacking rock breakage includes at least: constructing a hole opening wall to be pretreated; installing a water stopping device; jacking by a miniature push bench, loading a steel pipe joint, crushing rocks and deslagging until the miniature push bench is jacked by a preset length;
the mud pressing and returning at least comprises: preparing composite thick daub; pressing and injecting composite thick cement into the front of the miniature push bench in the pre-treated hole to squeeze and fill a stratum gap; forming an overpressure closed environment in front of the head of the miniature push bench in the hole by counter force generated by injecting the composite thick cement, and pulling back the steel pipe and the miniature push bench by using a pull-back device so as to enable the mud-pressing counter force and the pull-back force to jointly resist frictional resistance generated when the steel pipe and the miniature push bench retreat, wherein the mud-pressing and pull-back steps are synchronous; and (4) until all the pre-treatment holes are extruded and filled by the composite thick cement, and the micro push bench is completely withdrawn and sealed, so that the current rock treatment of the pre-treatment holes is completed.
Preferably, before the step of applying the pre-treatment to the opening wall, the method further comprises the following steps:
and constructing a horizontal geological exploration hole to find out the distribution range and the strength of the bedrock or the boulder and check the soil body reinforcing effect and the water leakage condition of the tunnel portal reinforcing area in the range to be tunneled of the large-section rectangular jacking pipe.
As a preferred scheme, after the soil body reinforcing effect and the water leakage condition of the portal reinforcing area in the range of the large-section rectangular jacking pipe to be tunneled are inspected, the method further comprises the following steps:
determining a layout scheme of the preprocessing holes according to distribution conditions of bedrock or boulders and cutter cutting blind areas of the large-section rectangular pipe jacking machine; the pretreatment holes are required to completely cover the rectangular pipe jacking machine section and the cutter head cutting blind area influenced by bedrock or boulder, and the length of the pretreatment holes at least penetrates through the found range of the bedrock or boulder.
As a preferred scheme, the pretreatment of the hole opening wall specifically comprises the following steps:
and determining the size of the hole of each pretreatment hole according to the arrangement range of each pretreatment hole, and constructing a plain concrete hole wall at the reserved hole door in the range to be tunneled of the large-section rectangular jacking pipe.
As a preferred scheme, the installation water stopping device specifically comprises:
and after the hole wall reaches the design strength, adopting a water drill to cut plain concrete in the range of the pretreated hole opening and a reinforced concrete foundation pit support structure in front of the hole opening, and installing a water stop device for construction of the miniature pipe jacking machine at the pretreated hole opening.
As the preferred scheme, the miniature push bench carries out jacking, steel pipe joint loading, rock crushing and slag tapping until the miniature push bench carries out jacking for a preset length, and the method specifically comprises the following steps:
and gradually jacking the miniature push bench into the pre-treatment hole to be treated currently, cutting broken rocks in the jacking process, discharging slag from the broken rocks through a mud-water circulating system, and synchronously installing steel pipe joints to replace the cut and broken rock stratum until the preset length of the pre-treatment hole is reached.
As a preferred scheme, the composite thick daub is prepared; pressing and injecting composite thick cement into the front of the micro pipe jacking machine in the pre-processing hole to extrude and fill the formation gap; forming an overpressure closed environment in front of the miniature push bench head in the hole by counter force generated by pressure injection of the composite thick cement, and pulling back the steel pipe and the miniature push bench by using a pull-back device so as to enable the counter force of the pressure cement and the pull-back force to jointly resist frictional resistance generated when the steel pipe and the miniature push bench retreat, wherein the steps of the pressure cement and the pull-back are synchronous; until all the pre-processing holes are extruded and filled by the compound thick cement, the miniature push bench is completely withdrawn and sealed, and the rock processing of the current pre-processing holes is completed, which specifically comprises the following steps:
after the micro pipe jacking machine jacks the current preprocessing hole to a preset length, preparing composite thick cement gum, and injecting the composite thick cement gum to the front of the chest plate of the micro pipe jacking machine in the current preprocessing hole through a grouting hole reserved on a cutter head in a pressing mode so as to extrude and fill stratum gaps;
in the process of pressure injection of the composite thick cement, after an overpressure closed environment is formed in front of the machine head in the hole through the counter force generated by pressure injection of the composite thick cement, the steel pipe joint and the micro pipe jacking machine can be pulled back easily by using a pull-back device, so that the friction resistance generated when the steel pipe and the micro pipe jacking machine retreat is resisted by the counter force of the pressure cement and the pull-back force together, wherein the steps of the pressure cement and the pull-back are synchronous;
and the steps of mud pressing and pulling back are executed in a reciprocating way, and finally, all the space of the current pretreatment hole is extruded and filled by the composite thick cement.
Preferably, the method further comprises the following steps:
and when the micro push bench is gradually extruded by the composite thick cement and retreats to the current hole opening of the pre-processed hole under the action of the pull-back device and is completely received, the hole opening of the current pre-processed hole is blocked by adopting a brick or a steel plate.
Preferably, after the bedrock or the boulder treatment of the current pretreated hole is completed, the method further comprises the following steps:
and sequentially carrying out miniature pipe jacking rock crushing and mud pressing retraction on the other pretreatment holes.
As a preferred scheme, after micro pipe jacking rock crushing and mud pressing retreating are carried out on all the pre-processing holes, a rock stratum is replaced into a processing stratum capable of adapting to cutting tunneling of a rectangular pipe jacking machine, and the method specifically comprises the following steps:
the method comprises the steps of clearing and retreating pre-treatment hole construction equipment and repairing a damaged structure in a working well, installing a water stopping device for rectangular pipe jacking construction at a reserved hole door in a large-section rectangular pipe jacking range to be tunneled, and installing and debugging a rectangular pipe jacking machine, so that the large-section rectangular pipe jacking machine can smoothly jack into a treated stratum for construction until a tunnel is communicated.
Compared with the prior art, the embodiment of the invention has the following beneficial effects:
according to the technical scheme, by the method combining the miniature pipe jacking rock crushing and mud jacking retraction, the miniature pipe jacking construction quickly and efficiently breaks bedrock or boulder in the range to be tunneled of the large-section rectangular pipe jacking, and reduces the strength and size of the rock; and then, performing mud pressing and withdrawing construction, namely injecting composite thick cement glue in front of the micro pipe jacking machine in the pre-treated hole in a pressing mode to squeeze and fill a stratum gap, simultaneously injecting the composite thick cement glue to generate certain counter force and form an overpressure closed environment in front of a micro pipe jacking machine head in the hole, then utilizing a withdrawing device to withdraw the steel pipe together with the micro pipe jacking machine, wherein the mud pressing counter force and the withdrawing force resist the frictional resistance generated when the steel pipe and the micro pipe jacking machine are withdrawn together, and the mud pressing and the withdrawing are synchronous. And (3) injecting the same or even excessive composite thick cement into a cavity generated by the pullback, so that the injected composite thick cement generates a certain counter force to facilitate the miniature push bench and the steel pipe joint to retreat under the action of the pullback device, and the mud pressing and the pullback are circularly repeated until all the pretreatment holes are extruded and filled by the composite thick cement and the miniature push bench is completely withdrawn and sealed.
By the method combining the two technologies, the rock stratum is effectively replaced by the low-strength processing stratum which can adapt to cutting and tunneling of the rectangular pipe jacking machine. The method has the advantages of unlimited construction pretreatment length, larger coverage area, less pretreatment construction times, effectively reduced disturbance to stratum, controllable ground settlement, controllable jacking posture in upper soft and lower hard stratum with bedrock or boulder during subsequent large-section rectangular pipe jacking construction, difficult deflection, relatively uniform cutter head stress, reduced cutter head tunneling torque, smooth spiral unearthing, smooth jacking engineering and the like.
Furthermore, the technical scheme of the invention has strong adaptability to different stratums such as bedrock or boulder, large pretreatment coverage area, simple construction process, high construction speed, cost saving, small disturbance to the stratums during construction, safer construction and controllable sedimentation, and can crush the rocks in the pretreatment holes through the miniature push bench, so that the construction process is efficient and safe.
Drawings
FIG. 1: the method comprises the steps of a flow chart of a bedrock and boulder pretreatment method of the large-section rectangular jacking pipe provided by the embodiment of the invention;
FIG. 2: the horizontal geological exploration hole distribution schematic diagram provided by the embodiment of the invention;
FIG. 3: the layout of the pretreatment holes is schematically shown in the embodiment of the invention;
FIG. 4 is a schematic view of: the concrete opening wall construction method is a concrete opening wall construction schematic diagram provided by the embodiment of the invention;
FIG. 5: the core-taking schematic diagram of the hole drilling machine for preprocessing provided by the embodiment of the invention;
FIG. 6: the construction schematic diagram of the water stopping device for the pre-treated hole provided by the embodiment of the invention is shown;
FIG. 7: a construction schematic diagram of each pretreatment hole provided by the embodiment of the invention;
FIG. 8: the embodiment of the invention provides a schematic drawing of the jacking of a miniature push bench;
FIG. 9: the embodiment of the invention provides a schematic retraction diagram of a micro push bench;
FIG. 10: the mud jacking and returning schematic diagram of the miniature push bench provided by the embodiment of the invention is shown;
FIG. 11: the schematic diagram of the receiving and hole sealing of the miniature push bench provided by the embodiment of the invention is shown;
FIG. 12: the large-section rectangular pipe jacking tunnel portal repair schematic diagram provided by the embodiment of the invention;
FIG. 13: the large-section rectangular pipe jacking water stopping device provided by the embodiment of the invention is schematically arranged.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without inventive step based on the embodiments of the present invention, are within the scope of protection of the present invention.
The invention provides a method for pretreating bedrock and boulder of a large-section rectangular push pipe, namely, the method is mainly used for pretreating the bedrock or the boulder in a range which is penetrated by a large-section rectangular push pipe machine in specific implementation, and the following conditions can occur when the large-section rectangular push pipe machine (called a large push pipe machine for short) is pushed into a bedrock or boulder stratum: 1) Due to the fact that the strength difference of rock and soil bodies is large, tunneling construction is conducted in the stratum with the upper portion soft and the lower portion hard, the cutter head of the large push bench is uneven in stress, and the jacking axis and the posture of the large push bench are prone to being changed greatly; 2) High-strength rocks are easy to generate larger abrasion on a large push bench cutter head and further lock the push bench; 3) The large boulder is easy to clamp a cutter head of the large push bench, block a spiral soil outlet and the like, and the large push bench can be pushed to fail under the above conditions. Therefore, in order to avoid the above situation when the large pipe pushing jack performs tunnel boring, it is necessary to perform pretreatment of bedrock or boulder before the large pipe pushing jack works.
The embodiment of the invention adopts a pretreatment method for treating the stratum, which comprises the steps of crushing the rock by using a miniature push bench which can tunnel in a bedrock or boulder stratum with the rock strength of more than 40Mpa, then pressing and injecting composite thick cement to extrude and fill the stratum, resisting the frictional resistance of a steel pipe joint and the retraction of the miniature push bench under the combined action of the counterforce generated by pressing and injecting the composite thick cement in front of a head of the miniature push bench in a hole and the pulling force generated by a pullback device, and finally completely replacing the rock stratum by the composite thick cement, so as to effectively control the ground settlement and ensure the smooth implementation of the subsequent large-section rectangular push bench. The miniature push bench has the characteristics of capability of efficiently crushing bedrock or boulder with higher rock strength, unlimited jacking construction length, large coverage area, difficulty in hole channeling, controllable posture and guaranteed construction precision, adopts a green, safe, environment-friendly and efficient slurry balanced push bench method for jacking, has small formation disturbance caused by construction, controllable ground settlement, small influence on the surrounding environment and simple and quick process, and is safe, environment-friendly and efficient; the method is characterized in that the tunneling processing stratum of the miniature push bench is filled by adopting composite thick cement extrusion, namely, the composite thick cement is injected under pressure while the steel pipe joint and the miniature push bench are pulled back under the combined action of counter force generated by injecting the composite thick cement and pulling force generated by a pull-back device, the mud pressing and the pulling back are synchronous until all pretreatment holes are completely filled by the composite thick cement extrusion, the miniature push bench returns and receives the composite thick cement completely, the disturbance of the construction stratum in the process is small, the ground settlement is controllable, the processed stratum can adapt to the cutting tunneling of a large-section rectangular push bench cutter head, and the optimization and improvement of the existing basement rock pretreatment technology are realized.
Example one
Referring to fig. 1, a method for pre-treating a bedrock and a boulder of a large-section rectangular jacking pipe provided in an embodiment of the present invention at least includes the following steps S101 to S102:
step S101: and crushing the rocks of the miniature jacking pipe.
Wherein, the micro pipe jacking rock crushing at least comprises the following steps S201-S203:
s201: and constructing a hole wall of the pretreatment hole 3.
As a preferable scheme of this embodiment, before the applying the wall of the opening of the pre-treated hole 3, the method further comprises:
and constructing a horizontal geological exploration hole to find out the distribution range and the strength of the bedrock or the boulder and check the soil body reinforcing effect and the water leakage condition of the tunnel portal reinforcing area in the range to be tunneled of the large-section rectangular jacking pipe.
In this embodiment, please refer to fig. 2, according to the existing geological survey report, a plurality of horizontal exploratory holes 4 are made in the range of the portal ring of the large push bench, the thickness and the fluctuation of the bed rock or boulder distribution layer are found out, the engineering properties of the bed rock are further obtained, the influence of the bed rock on the jacking of the large-section rectangular push bench is evaluated, the reinforcing effect and the leakage condition of the soil body in the reinforcing area at the reserved portal of the large-section rectangular push bench are checked, and if the large-area leakage water occurs, the reinforcement needs to be performed.
Further, the horizontal detecting holes 4 are arranged according to the principle from bottom to top, and when no bedrock exists in the core samples exposed from the horizontal detecting holes 4 in the same row, the horizontal detecting holes 4 in the upper row are stopped. The horizontal probe hole 4 is implemented by a horizontal core drill, and preferably, the diameter of the drill hole is phi 108mm.
Referring to fig. 2, in another embodiment, three rows of horizontal probing holes 4 are arranged, the core sample of the two lower rows of horizontal probing holes 4 reveals the bedrock and the boulder with large diameter, but the uppermost row of horizontal probing holes 4 does not find the bedrock basically, so the pretreatment range of the bedrock or the boulder is defined as the vertical boundary by the elevation of the uppermost row of horizontal probing holes 4, the lower boundary by the elevation of the bottom of the portal steel ring 1 reserved in the large-section rectangular top pipe, and the horizontal boundary by the portal steel ring border line reserved in the large-section rectangular top pipe, that is, the arrangement range of the pretreatment holes 3. The vertical distance between the horizontal probing holes is 1.0m to 1.5m, three to five horizontal probing holes 4 can be arranged in the same row, and the distance is determined according to the section size of the large-section rectangular jacking pipe.
As a preferred embodiment of this embodiment, after the checking the soil body reinforcing effect and the water leakage condition of the hole door reinforcing area in the range to be tunneled of the large-section rectangular jacking pipe, the method further includes:
determining a layout scheme of the preprocessing holes 3 according to distribution conditions of bedrock and boulders by combining a cutter head layout form and cutter head cutting blind areas of a large-section rectangular pipe jacking machine; the pretreatment holes 3 are required to completely cover the rectangular pipe jacking machine section and the cutter head cutting blind area influenced by bedrock, and the length of the pretreatment holes 3 at least penetrates through the found bedrock range.
In the present embodiment, referring to fig. 3, for example, according to the thickness and the fluctuation condition of the bed rock and the boulder distribution layer, the pretreatment holes 3 are reasonably arranged at the position of the large-section rectangular pipe jacking tunnel portal according to the principle from bottom to top, and the position, the distance and the number of the pretreatment holes 3 are determined.
Since the cutter head cutting range 21 of the large push bench is circular, a cutter head cutting blind area 22 exists when rectangular or quasi-rectangular large cross-section cutting is performed. The pretreatment holes 3 are made by adopting a mud-water balanced type micro pipe jacking machine with a rock breaking function, and the inner diameter of the pretreatment holes is preferably DN 600-DN 1200mm. Wherein the range of pretreatment is required to completely cover the large-section rectangular pipe jacking machine section and the cutter head cutting blind area 22 influenced by bedrock and boulder.
In this embodiment, the length of the pretreatment hole 3 is determined according to the distribution of bedrock and boulders, the pretreatment can be performed from the side with a large distribution range of bedrock and boulders, the opposite-top construction can also be performed from the rectangular pipe-jacking initial well portal and the receiving well portal, and the distribution of bedrock and boulders is specifically determined. Meanwhile, the length of the pretreatment holes 3 at least penetrates through the distribution range of the corresponding bedrock and the boulder.
As a preferred scheme of this embodiment, the applying of the hole wall of the pretreatment hole 3 specifically includes:
and determining the size of the hole of each pretreatment hole 3 according to the distribution range of each pretreatment hole 3, and constructing a plain concrete hole wall at the reserved hole door of the large-section rectangular jacking pipe to-be-tunneled range.
It should be noted that, in this embodiment, referring to fig. 4, according to the arrangement range of the pre-processing hole 3, a concrete retaining wall 7 is implemented in the water-stopping steel ring of the large-section rectangular pipe-jacking portal and closely attached to the working well enclosure structure as the portal structure of the pre-processing hole 3. The height of the concrete retaining wall 7 should exceed the top of the hole of the pretreatment hole 3 by 20cm to 30cm. In addition, a plurality of temporary steel supports 5 are required to be arranged above the concrete retaining wall 7 to support the water-stopping steel ring 1 pre-buried in the range of the large-section rectangular pipe jacking opening.
In this embodiment, the concrete retaining wall 7 is connected with the working well enclosure structure pile through the steel bars 6, so that the overall stability of the retaining wall is improved. The tie bars 6 are arranged along the circumferential direction of the concrete retaining wall and need to be arranged outside the construction influence range of the pretreatment holes 3.
S202: the water stop device 33 is installed.
As a preferable scheme of this embodiment, the installation water stopping device 33 specifically includes:
and after the wall of the hole opening reaches the designed strength, cutting the concrete retaining wall 7 in the range of the hole opening of the pretreatment hole 3 and the reinforced concrete foundation pit support structure in front of the hole opening by using a water drill, and installing a water stopping device 33 for construction of the miniature pipe jacking machine at the hole opening of the pretreatment hole 3.
In this embodiment, please refer to fig. 5 and 6, a small-sized drilling machine is used to successively drill the concrete retaining wall 7, the water-stopping steel ring (local part) pre-embedded in the large-section rectangular pipe-jacking portal and the core sample of the enclosure structure along the circular outline of the portal of the pre-processing portal 3, the core sample 31 of the drilling machine inside the portal is taken out after drilling and cutting, then the portal of the pre-processing portal 3 is leveled, the bolt hole 10 is drilled at the periphery of the small portal in the range to be jacked by the micro pipe jacking machine, the micro pipe-jacking portal steel plate 32, the rubber curtain cloth and the pressing plate are sequentially installed and fixed by the expansion bolt, and the water-stopping device 33 for the construction of the micro pipe jacking machine of the pre-processing portal 3 is completed. Wherein the drilling diameter of the small-sized drilling machine is preferably phi 100mm.
In another embodiment, when the drilling machine is broken, temporary plugging materials are prepared in the well at any time to plug the miniature pipe jacking opening 34, so as to prevent soil and water outside the opening from flowing into the working well from the drilling hole.
S203: and (4) jacking by using the miniature pipe jacking machine, loading steel pipe joints, crushing rocks, and deslagging until the miniature pipe jacking machine is jacked by a preset length.
As the preferred scheme of this embodiment, miniature push bench advances in top, dress steel pipe section, rock breakage, slag tap, until advancing preset length, specifically is:
and gradually jacking the miniature push bench into the pre-treatment hole 3 to be treated currently, cutting broken rocks in the jacking process, discharging slag from the broken rocks through a mud-water circulating system, and synchronously installing steel pipe joints to replace the cut and broken rock stratum until the preset length of the pre-treatment hole 3 is reached.
It should be noted that, in this embodiment, the micro push bench is hoisted to the originating guide rail after the examination of the supporting facilities such as the originating base, the originating guide rail, the main push cylinder and cylinder frame, the reclining, the push iron, and the like, which are installed in the working well corresponding to the pre-processing hole 3, so as to complete the installation and debugging of the micro push bench.
It should be noted that the working well may be a rectangular pipe jacking originating well or a rectangular pipe jacking receiving well, as shown in fig. 7, and the hatched portion is a lining wall 8 in the working well.
Please refer to fig. 7 and 8, according to the micro pipe jacking construction process flow, the micro pipe jacking machine 110 is gradually jacked into the pretreatment hole 3 in the rectangular pipe jacking receiving hole 14, and the crushed rock is jacked and cut while slag is discharged through mud-water circulation until the designed length of the treatment hole is reached. And in the process, a steel pipe joint is timely installed, a mud pressing pipe is installed in the pipe joint and is connected to a reserved grouting hole in the miniature push bench, meanwhile, the ground surface settlement deformation is monitored in real time, and the jacking parameters of the miniature push bench are timely fed back so as to be convenient to adjust. The longitudinal joint between the steel pipe sections is ensured to have certain tensile strength. Wherein, the micro pipe jacking construction is realized according to the operation steps in the special micro pipe jacking construction scheme. As shown in fig. 7, the inner contour 12 and the outer contour 11 are arranged on two sides of the large pipe jacking machine tunnel door steel ring, so that the water stopping device for large-section rectangular pipe jacking construction can be conveniently mounted and fixed, the stability and the water stopping effect of the water stopping device can be ensured, and finally the construction safety of the large-section rectangular pipe jacking can be ensured.
Step S102: pressing mud and returning.
The mud pressing and returning process at least comprises the following steps of S204-S207:
s204: preparing the composite thick daub 35.
It should be noted that the composite thick daub 35 has the characteristics of high concentration, low strength, good plastic fluidity, low permeability, good stability and the like. Preferably, the composite thick cement 35 is a slurry prepared from bentonite, water, cement, high polymer additives and other materials according to a certain proportion.
Further, the composite thick cement 35 with certain strength can squeeze and fill the formation gap to prevent formation loss, and plays an important role in the mud pressing return process. The strength of the composite thick mortar 35 is not too high, is low, can be weakly solidified in a short time, and can support the weight of the upper soil mass and adapt to cutting of a cutter head of a rectangular push bench. Further, the composite thick mortar 35 has good plastic fluidity, and since the slurry is conveyed from the ground to the underground and then into the treatment hole in a pumping mode, the corresponding thick mortar can be easily injected to the design position of the pretreatment hole 3 only by having certain plasticity and self-fluidity; furthermore, the composite thick mortar 35 can generate a certain pressure when being injected into the pre-processing hole in front of the head of the micro push bench so as to facilitate the retraction of the micro push bench and the steel pipe joint under the action of the pull-back device. In addition, the composite thick daub 35 should have low permeability, i.e. have certain water stopping and difficult segregation and loss effects, and facilitate the water prevention of pipe joints when the jacking pipe is jacked in, and meanwhile, the composite thick daub is difficult to loss and permeate into the stratum. Furthermore, the composite thick mortar 35 plays a role in lubrication and drag reduction during jacking of the jacking pipe, and a stable lubricating slurry sleeve can be formed due to good stability of the composite thick mortar, so that the jacking pipe machine and the pipe joints can move forwards in the slurry sleeve and can be effectively isolated from the soil body, and the jacking or retraction frictional resistance can be greatly reduced.
S205: and (3) injecting composite thick cement 35 to the front of the micro pipe jacking machine in the pretreatment hole 3 to squeeze and fill the formation gap.
It should be noted that, in order to effectively squeeze and fill the formation gap, avoid formation loss and control surface subsidence, the mud-pressing amount is measured and calculated by 1.5 to 2 times of the excavation amount of the micro pipe-jacking machine. Mud pressing amount A of composite thick daub 35 per linear meter i1 ＝kπD 2 (V) total mud pressure of a single pretreatment hole 3 is V i ＝A i1 (L i －L jg －L wh －L dq ) (ii) a Wherein D is the excavation diameter of the miniature push bench, L i Designed length for pre-treating the holes 3, L jg For the length of the reinforcing section of the hole door,L wh is the thickness of the enclosure, L dq Taking the thickness of the plain concrete opening wall as the coefficient k, and taking the k as 1.5-2.
It should be noted that the amount of the composite thick mortar 35 injected under pressure in a single pretreatment hole is equal to or greater than the amount of the cavity generated by the pull-back, so as to form an overpressure closed environment, which is beneficial to supporting and pressing the surrounding formation through the overpressure reaction force to avoid formation loss, and is also beneficial to the steel pipe joint and the micro push bench to retreat under the action of the pull-back device.
S206: and forming an overpressure closed environment in front of the miniature push pipe machine head in the hole through the counter force generated by injecting the composite thick mortar 35, and then pulling back the steel pipe joint and the miniature push pipe machine by using a pull-back device.
As a preferable scheme of this embodiment, the preparation of the composite thick daub 35; pressing and injecting composite thick cement 35 to the front of the micro pipe jacking machine in the pretreatment hole 3 to squeeze and fill the formation gap; forming an overpressure closed environment in front of the miniature push bench head in the hole by counter force generated by pressure injection of the composite thick mortar 35, and pulling back the steel pipe and the miniature push bench by using a pull-back device so as to enable the pressure mud counter force and the pull-back force to jointly resist frictional resistance generated when the steel pipe and the miniature push bench retreat, wherein the steps of pressure mud and pull-back are synchronous; until all the pre-processing holes are squeezed and filled by the composite thick cement 35 and the micro push bench is completely withdrawn and sealed, the rock processing of the current pre-processing holes is completed, which specifically comprises the following steps:
after the micro push bench is pushed into the current preprocessing hole 3 to a preset length, preparing composite thick cement 35, and injecting the composite thick cement 35 to the front of the chest plate of the micro push bench in the current preprocessing hole through a grouting hole reserved on a cutter head in a pressing mode to squeeze and fill stratum gaps; in the process of injecting the composite thick daub 35, after an overpressure closed environment is formed in front of the machine head in the hole through the counter force generated by injecting the composite thick daub 35, the steel pipe section and the micro pipe jacking machine can be pulled back easily by using a pull-back device, so that the friction force generated when the steel pipe and the micro pipe jacking machine retreat is resisted by the mud pressing counter force and the pull-back force together, wherein the steps of mud pressing and pull-back are synchronous; and the steps of mud pressing and pulling back are executed in a reciprocating way, and finally, all the space of the current pretreatment hole is extruded and filled by the composite thick daub 35.
It should be noted that, in the process of injecting the composite thick cement 35, the friction resistance generated when the steel pipe and the micro pipe jacking machine are retracted is resisted by the mud pressing counterforce and the pulling force together, the injected composite thick cement 35 can generate a certain counterforce to squeeze and fill the formation gap in front of the micro pipe jacking machine and form overpressure to support the upper soil body to prevent formation loss, meanwhile, the formed overpressure closed environment generates the counterforce for the micro pipe jacking machine head to facilitate the retraction of the micro pipe jacking machine and the steel pipe joint under the action of the pulling device, and finally, all the space of the current pretreatment hole 3 is squeezed and filled by the composite thick cement 35, so that ground settlement caused by formation loss is avoided.
In this embodiment, the sum of the reaction force generated by injecting the composite thick mortar 35 and the pulling force generated by the pulling-back device needs to be greater than or equal to the frictional resistance generated during the retraction, and if the frictional resistance of the steel pipe joint and the retraction of the micro pipe jacking machine in a certain pre-treated hole is calculated to be 5000 kn and the pulling force provided by the pulling-back device is 2500 kn, the reaction force generated during injecting the composite thick mortar 35 needs to be greater than or equal to 2500 kn.
Furthermore, the ground surface sedimentation deformation is monitored in real time during mud pressing and returning, so that the mud pressing pressure, the returning tension and the returning speed are adjusted in real time. The pressure injection of thick mud and the pulling-back of the push bench must be carried out while pulling, the injection amount and the volume of a cavity generated by pulling-back must be kept consistent even the injection amount is excessive under overpressure, and the counter force generated by injecting the thick mud under overpressure is beneficial to the retraction of the micro push bench and the steel pipe joint under the action of the pulling-back device, so that the injection after pulling is strictly forbidden.
In this embodiment, after the micro pipe pushing machine is pushed to the designed length of the processing hole, the composite thick cement 35 is injected to the front of the breast plate of the micro pipe pushing machine through the grouting hole, a certain amount of the composite thick cement 35 is injected to squeeze and fill the gap between the cutter head of the micro pipe pushing machine and the ground, and then the steel pipe joint and the micro pipe pushing machine are gradually pulled back in the working well through the jack device while injecting the composite thick cement 35.
Further, the pressure injection of the composite thick cement 35 and the pulling back of the steel pipe joint and the micro pipe jacking machine are carried out simultaneously, an overpressure sealing environment is formed in front of the micro pipe jacking machine head in the hole through the counterforce generated by the pressure injection of the composite thick cement 35, the steel pipe joint and the micro pipe jacking machine can be pulled back easily by utilizing the pulling back device, and the pressure injection and the pulling back are synchronous. The shot size and the cavity volume generated by the pull-back must be consistent or even over-pressurized and over-injected, and the pull-first and the post-injection are strictly forbidden. If an overpressure environment is not formed in front of the micro pipe jacking machine head to generate a certain counter force for the machine head, a larger pulling force needs to be provided for the pull-back device in the working well, so that the pull-back device is easily broken or the micro pipe jacking machine is disconnected from the steel pipe joint, and the loss of the periphery of the steel pipe joint and the stratum of an overlying soil body is caused seriously, thereby causing the settlement deformation of the ground.
It should be noted that when the steel pipe joint and the micro pipe jacking machine are pulled back, a pull-back connecting piece is welded on the steel pipe joint in the well, and the connecting piece is effectively connected with the pull-back jack equipment. The head and the tail ends of each section of steel pipe are connected in a welding mode, and the front end of the first section of steel pipe is connected with the tail of the miniature pipe jacking machine in a welding mode.
In this embodiment, please refer to fig. 9 and 10, which are schematic retraction diagrams of a micro push bench, a pre-processing push bench initial well and a large-section rectangular push bench receiving well are the same working well, during the pushing process of the large-section rectangular push bench 91, the middle lower part of the section of the large-section rectangular push bench meets the bedrock and the large-diameter boulder 9, the cutterhead of the large-section rectangular push bench 91 cannot cut and tunnel the bedrock and the boulder 9, and the micro push bench 110 is required to crush the bedrock and the boulder 9. The micro pipe jacking machine 110 jacks, pipes, rocks and slag in the arranged pretreatment holes, after the pretreatment holes reach the design length of the current pretreatment holes, the composite thick cement 35 is injected under pressure, the steel pipe sections and the micro pipe jacking machine are retracted under the combined action of the counter force generated by the cement pressing and the pulling force generated by the pulling device, and the steel pipe sections 100 which are connected end to end are retracted to be recovered in the working well. When all the laid pretreatment holes are constructed, bedrock and boulders in the tunneling range of the large-section rectangular pipe jacking machine 91 are replaced and filled with the composite thick cement, the replaced stratum can adapt to cutting tunneling of the large-section rectangular pipe jacking machine 91, and then the large-section rectangular pipe jacking machine 91 can be jacked and constructed to be communicated with the tunnel 92 according to the designed sideline line 93 (or the designed range of the tops of the large pipe jacking pipe joints and the sideline line 93).
S207: and (4) until the pretreated holes 3 are completely extruded and filled by the composite thick mortar 35 and the miniature push bench is completely withdrawn and sealed, so that the bedrock and boulder treatment of the pretreated holes 3 is completed.
As a preferred scheme of this embodiment, after the micro push bench is gradually squeezed by the composite thick mortar 35 and retreats to and completely receives the opening of the current pre-processing hole 3 under the action of the retracting device, the opening of the current pre-processing hole 3 is blocked by a brick or a steel plate.
In this embodiment, referring to fig. 11, when the micro pipe jacking machine retreats to the plain concrete hole wall, the composite thick mortar 35 stops being injected by pressure, and then the micro pipe jacking machine retreats into the working well quickly, so as to obtain the region 111 where the pretreatment is completed, and meanwhile, it is observed whether the injection amount of the composite thick mortar 35 is sufficient, and it is required to have strong overall self-stability, that is, the hole plugging 34 of the micro pipe jacking machine shown in fig. 12. And then, a brick or steel plate is adopted to plug the water stopping device 33 of the detachable treatment hole behind the hole, so that the next pretreatment hole is facilitated to be used as a hole structure.
Furthermore, in the jacking process of the miniature pipe jacking machine, the water-stop steel ring and the lining wall at the reserved hole door of the large-section rectangular pipe jacking working well may be damaged, so that the water-stop steel ring and the lining wall of the large pipe jacking work well need to be locally repaired 8, and the starting and jacking safety of the large-section rectangular pipe jacking is ensured.
As a preferable scheme of the present embodiment, after the rock breaking treatment of the current pre-treatment hole 3 is completed, the method further includes:
and sequentially carrying out miniature pipe jacking rock crushing and mud pressing retraction on the rest of the pretreatment holes 3.
In this embodiment, the pretreatment of the bedrock and the boulder of all the pretreatment holes 3 is realized, the miniature push bench is adopted to cut and crush the rocks within the range of the rest pretreatment holes 3, the rocks are all pushed to the designed length of the pretreatment holes 3, the composite thick cement 35 is injected under pressure to fill the formation gap, the steel pipe joint and the miniature push bench are used for overcoming the returning friction resistance under the combined action of the counter force generated by injecting the composite thick cement 35 in the holes and the pulling force generated by the pulling device while extruding and filling the formation gapAnd pulling back the hole, and then plugging the hole opening. The total mud pressing amount of the composite thick daub 35 is V 1 ＝ΣV i1 。
As a preferred scheme of this embodiment, after micro pipe-jacking rock crushing and mud-jacking retraction are performed on all the pre-processing holes 3, the rock stratum is replaced by a processing stratum capable of adapting to cutting and tunneling of a rectangular pipe jacking machine, which specifically includes:
and (3) clearing and retreating the construction equipment of the pre-treatment hole 3 and repairing a damaged structure in the working well, installing a water stop device 33 for rectangular pipe jacking construction at a reserved hole door of a large-section rectangular pipe jacking range to be tunneled, and installing and debugging a large-section rectangular pipe jacking machine, so that the large-section rectangular pipe jacking machine can be smoothly jacked for construction in the range to be tunneled and the treated stratum until the tunnel is communicated.
Please refer to fig. 13, the construction facilities and sites of the pre-treatment holes 3 are cleared, that is, the abrasion of the water-stop steel plate pre-embedded in the large-section rectangular pipe-jacking tunnel door due to the pre-treatment construction of the bedrock and the boulder is repaired, and the temporary steel supports are removed. And chiseling out a space enclosing structure in the large-section rectangular pipe jacking portal ring and a plain concrete portal wall constructed during pretreatment construction, and mounting large pipe jacking machine water stopping devices 13 such as rubber curtain cloth on the portal water stopping steel plate of the large-section rectangular pipe jacking. And (4) according to the rectangular pipe-jacking construction process flow, implementing the tunneling construction of the large-section rectangular pipe-jacking tunnel until the tunnel is completely communicated.
Particularly, according to the distribution conditions of bedrock and boulders, a part of cutterheads of the large-section rectangular jacking pipe is provided with high-strength alloy cutters with high wear resistance.
The miniature push bench in the embodiment of the invention has the characteristics of capability of efficiently crushing bedrock or boulder with higher rock strength, unlimited jacking construction length, large coverage area, difficulty in hole channeling, controllable posture and guaranteed construction precision; the mud-water balanced pipe jacking method is adopted for jacking construction, so that the stratum disturbance caused by construction is small, the ground settlement is controllable, and the influence on the surrounding environment is small; the process is simple and the construction speed is high.
Meanwhile, the composite thick mortar is adopted to extrude and fill the treated stratum of the miniature push bench, namely, the steel pipe joint and the miniature push bench are pulled back under the action of the pull-back device while the composite thick mortar is injected under pressure, so that the stratum disturbance is reduced, the stratum loss is avoided, and the ground settlement is controllable. By the matrix and boulder pretreatment technology provided by the embodiment, the rock stratum is effectively replaced into a low-strength treatment stratum which can adapt to cutting and tunneling of the rectangular pipe jacking machine. The whole construction pretreatment coverage is larger, the pretreatment construction frequency is less, the disturbance to the stratum is effectively reduced, the ground settlement is controllable, the jacking gesture is controllable and the deflection is not easy to occur in the upper soft and lower hard stratum with bedrock or boulder during the subsequent large-section rectangular pipe jacking construction, the stress of a cutter head is relatively uniform, the tunneling torque of the cutter head is reduced, the spiral soil discharging is smooth, the jacking engineering is smooth and safe, and the like.
The above embodiment is implemented, and has the following effects:
according to the technical scheme, by the method combining the miniature pipe jacking rock crushing and mud jacking retraction, the miniature pipe jacking construction is quick, bedrock or boulder in the range to be tunneled of the large-section rectangular pipe jacking can be efficiently broken, and the strength and size of the rock are reduced; and then, performing mud pressing retraction construction, namely performing pressure injection on the composite thick cement in front of the micro push bench in the pre-treated hole to squeeze and fill a formation gap, forming an overpressure closed environment in front of a micro push bench head in the hole by using counter force generated by pressure injection of the composite thick cement, and pulling back the steel pipe together with the micro push bench by using a pull-back device, wherein the mud pressing counter force and the pull-back force jointly resist frictional resistance generated when the steel pipe joint and the micro push bench retract, and the mud pressing retraction and the pull-back are synchronous. And (3) injecting the same or even excessive composite thick cement into a cavity generated by the pullback, so that the counter force generated by the injected composite thick cement is beneficial to the retraction of the miniature push bench and the steel pipe joint under the action of the pullback device, and the mud pressing and the pullback are circularly repeated until all the pre-treatment holes are extruded and filled by the composite thick cement and the miniature push bench is completely withdrawn and sealed. By the method combining the two technologies, the rock stratum is effectively replaced by the low-strength processing stratum which can adapt to cutting and tunneling of the rectangular pipe jacking machine. The method has the advantages of unlimited construction pretreatment length, larger coverage area, less pretreatment construction times, controllable ground settlement, controllable jacking posture in upper soft and lower hard strata with bedrock or boulders during subsequent large-section rectangular pipe jacking construction, difficulty in deflection, relatively uniform cutter stress, reduction of cutter tunneling torque, smooth spiral unearthing, smooth jacking engineering and the like.
Furthermore, the technical scheme of the invention has strong adaptability to different stratums such as bedrock or boulder, large pretreatment coverage area, simple construction process, high construction speed, cost saving, small disturbance to the stratums during construction, controllable and safer construction settlement, and the rock in the pretreatment hole is crushed by the miniature push bench, so that the construction process is efficient and safe.
The above-mentioned embodiments are provided to further explain the objects, technical solutions and advantages of the present invention in detail, and it should be understood that the above-mentioned embodiments are only examples of the present invention and are not intended to limit the scope of the present invention. It should be understood that any modifications, equivalents, improvements and the like, which come within the spirit and principle of the invention, may occur to those skilled in the art and are intended to be included within the scope of the invention.
Claims (10)
1. A bedrock and boulder pretreatment method for a large-section rectangular jacking pipe is characterized by at least comprising the following steps:
crushing the miniature jacking pipe rock and pressing mud to retreat;
wherein, miniature pipe jacking rock breakage includes at least: constructing a hole opening wall to be pretreated; installing a water stopping device; jacking, pipe loading, rock crushing and slag discharging by a miniature pipe jacking machine until the miniature pipe jacking machine jacks a preset length;
the mud pressing and returning at least comprises: preparing composite thick daub; pressing and injecting composite thick cement into the front of the miniature push bench in the pre-treated hole to squeeze and fill a stratum gap; forming an overpressure closed environment in front of the head of the miniature push bench in the hole by counter force generated by injecting the composite thick cement, and pulling back the steel pipe and the miniature push bench by using a pull-back device so as to enable the mud-pressing counter force and the pull-back force to jointly resist frictional resistance generated when the steel pipe and the miniature push bench retreat, wherein the mud-pressing and pull-back steps are synchronous; and (4) until the pretreatment holes are completely extruded and filled with the composite thick cement, and the miniature push bench is completely withdrawn and sealed, so that the current rock treatment of the pretreatment holes is completed.
2. The method for pre-treating the bedrock and the boulder of the large-section rectangular jacking pipe as claimed in claim 1, further comprising, before said pre-treating the opening wall of the hole:
and constructing a horizontal geological exploration hole to find out the distribution range and the strength of the bedrock or the boulder and check the soil body reinforcing effect and the water leakage condition of the tunnel portal reinforcing area in the range to be tunneled of the large-section rectangular jacking pipe.
3. The pretreatment method for bedrock and boulder of large-section rectangular jacking pipe according to claim 2, characterized in that after said checking the soil body strengthening effect and water leakage condition of the portal strengthening area in the range of large-section rectangular jacking pipe to be tunneled, it further comprises:
determining a layout scheme of the preprocessing holes according to the distribution condition of bedrock or boulder and cutter cutting blind areas of a large-section rectangular push bench; the pretreatment holes are required to completely cover the rectangular pipe jacking machine section and the cutter head cutting blind area which are affected by the rock, and the length of the pretreatment holes at least penetrates through the found range of the bedrock or the boulder.
4. The method for pretreating bedrock and boulder of a large-section rectangular jacking pipe according to claim 3, wherein the method for pretreating the opening wall of the hole comprises the following specific steps:
and determining the size of the hole of each pretreatment hole according to the layout range of each pretreatment hole, and constructing a plain concrete hole wall at the reserved hole door of the large-section rectangular jacking pipe to-be-tunneled range.
5. The method for pretreating bedrock and boulder of a large-section rectangular jacking pipe according to claim 4, wherein the installation of the water stopping device specifically comprises the following steps:
and after the hole wall reaches the design strength, adopting a water drill to cut plain concrete in the range of the pretreated hole opening and a reinforced concrete foundation pit support structure in front of the hole opening, and installing a water stop device for construction of the miniature pipe jacking machine at the pretreated hole opening.
6. The pretreatment method for bedrock and boulder of large-section rectangular jacking pipe according to claim 1, wherein the miniature jacking pipe machine is used for jacking, loading steel pipe joints, breaking rocks and deslagging until jacking to a preset length, and specifically comprises the following steps:
and gradually jacking the miniature push bench into the pretreatment hole to be treated currently, cutting broken rocks in the jacking process, discharging slag from the broken rocks through a mud-water circulating system, and synchronously installing steel pipe joints to replace the rock stratum which is cut and broken until the preset length of the pretreatment hole is reached.
7. The method for pretreating bedrock and boulder of a large-section rectangular jacking pipe according to claim 1, wherein composite thick mortar is prepared; pressing and injecting composite thick cement into the front of the micro pipe jacking machine in the pre-processing hole to extrude and fill the formation gap; forming an overpressure closed environment in front of the head of the miniature push bench in the hole by counter force generated by injecting the composite thick cement, and pulling back the steel pipe and the miniature push bench by using a pull-back device so as to enable the mud-pressing counter force and the pull-back force to jointly resist frictional resistance generated when the steel pipe and the miniature push bench retreat, wherein the mud-pressing and pull-back steps are synchronous; until all the pre-processing holes are extruded and filled by the compound thick cement, the miniature push bench is completely withdrawn and sealed, and the rock processing of the current pre-processing holes is completed, which specifically comprises the following steps:
after the micro pipe jacking machine jacks the current preprocessing hole to a preset length, preparing composite thick cement gum, and injecting the composite thick cement gum to the front of the chest plate of the micro pipe jacking machine in the current preprocessing hole through a grouting hole reserved on a cutter head in a pressing mode so as to extrude and fill stratum gaps;
in the process of pressure injection of the composite thick cement, after an overpressure closed environment is formed in front of the machine head in the hole through the counter force generated by pressure injection of the composite thick cement, the steel pipe joint and the micro pipe jacking machine can be pulled back easily by using a pull-back device, so that the friction resistance generated when the steel pipe and the micro pipe jacking machine retreat is resisted by the counter force of the pressure cement and the pull-back force together, wherein the steps of the pressure cement and the pull-back are synchronous;
and the steps of mud pressing and pulling back are executed in a reciprocating way, and finally, all the space of the current pretreatment hole is extruded and filled by the composite thick cement.
8. The method for pre-treating the bedrock and the boulder of the large-section rectangular jacking pipe as claimed in claim 7, further comprising:
and when the micro push bench is gradually extruded by the composite thick cement and retreats to the hole opening of the current pre-processing hole under the action of the pull-back device and is completely received, the hole opening of the current pre-processing hole is blocked by bricks or steel plates.
9. The method for pre-treating the bedrock and the orphan stone of the large-section rectangular jacking pipe according to any one of claims 1 to 8, wherein after the bedrock or the orphan stone treatment of the current pre-treated hole is completed, the method further comprises the following steps:
and sequentially carrying out miniature pipe jacking rock crushing and mud pressing retraction on the rest of the pretreatment holes.
10. The method for pre-treating the bed rock and the boulder of the large-section rectangular pipe jacking according to claim 9, wherein after the micro pipe jacking rock crushing and mud pressing return of all the pre-treatment holes, the rock stratum is replaced into a treatment stratum capable of adapting to cutting excavation of the rectangular pipe jacking machine, and the method specifically comprises the following steps:
the method comprises the steps of clearing and retreating pre-treatment hole construction equipment and repairing a damaged structure in a working well, installing a water stopping device for rectangular pipe jacking construction at a reserved hole door of a large-section rectangular pipe jacking range to be tunneled, and installing and debugging a rectangular pipe jacking machine, so that the large-section rectangular pipe jacking machine can be smoothly jacked in a treated stratum for construction until a tunnel is communicated.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116066130A (en) * | 2023-03-06 | 2023-05-05 | 中交第一航务工程局有限公司 | Rectangular jacking pipe construction method for long-distance full-section rock stratum condition |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN116066130A (en) * | 2023-03-06 | 2023-05-05 | 中交第一航务工程局有限公司 | Rectangular jacking pipe construction method for long-distance full-section rock stratum condition |
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