CN111140243A

CN111140243A - Slurry balance shield machine and pipe-jacking tunneling construction method applying same

Info

Publication number: CN111140243A
Application number: CN201911407133.XA
Authority: CN
Inventors: 薛庆文; 刘刚; 林裕; 尹超; 田泽辉; 傅宇; 张宇; 赵振蜀
Original assignee: Chengdu Second Construction Engineering Co Ltd Of Cdceg
Current assignee: Chengdu Second Construction Engineering Co Ltd Of Cdceg
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-05-12

Abstract

The invention discloses a slurry balance shield tunneling machine which comprises a rotatable cutter head and a cutting mechanism, wherein the cutter head is provided with a conical surface and a propelling surface, the cross section of the conical surface is gradually reduced, and a feeding hole is formed in the propelling surface; the cutting mechanism comprises a first cutting assembly and a second cutting assembly; the first cutting assembly comprises a cutter arranged on the cutter head, and the cutter comprises a hob and a scraper; the hob comprises a first hob distributed on the propelling surface and a second hob annularly distributed on the conical surface; the scrapers comprise a first scraper distributed on the feed inlet, a second scraper distributed on the pushing surface and a third scraper annularly distributed on the conical surface; the second cutting assembly includes a twist leg supporting the cutter head and rotating and a disc forming a crushing gap with the twist leg. Crushed stone obtained by crushing (primary crushing) by the cutter can enter the crushing bin from the feeding hole and further enter the crushing gap so as to be secondarily crushed under the mutual rotary shearing of the torsion leg and the disc body.

Description

Slurry balance shield machine and pipe-jacking tunneling construction method applying same

Technical Field

The invention relates to the technical field of underground excavation pipeline construction, in particular to a slurry balance shield machine and a top pipe tunneling construction method using the same.

Background

The construction of the electric power tunnel generally adopts an open cut method to improve the construction efficiency. However, the open cut rule is not applicable to the construction of the electric power tunnel which needs to cross over the special road section such as the existing road with large traffic flow. For the road sections where the open cut method is not suitable, a novel construction method, namely pipe jacking construction, is developed. The pipe-jacking construction belongs to a non-excavation construction method, and is a pipeline burying construction technology without excavation or with few excavations. The pipe jacking construction overcomes the friction between the pipe of the tunneling equipment and the surrounding soil by means of jacking force, so that the tunneling equipment (such as a shield machine) is pushed from an originating well through the soil layer to a receiving well to be hoisted, and the electric tunnel pipe is buried between the two wells one by one after the tunneling equipment according to the designed gradient.

However, it is a difficult project to build the electric power tunnel near the existing subway line, and especially when the subway line needs to be traversed, the construction difficulty is very large because disturbance to the subway line needs to be fully considered. Therefore, for the construction of an electric power tunnel which passes through an existing highway downwards and a subway line upwards, an efficient and safe pipe jacking construction scheme is not available.

At present, large-particle-size pebble stratums exist in partial areas of China, and underground water is abundant. When facing this type of geological conditions, if adopt traditional artifical excavation to carry out the push pipe construction, need carry out precipitation and handle to lead to the stratum to subside and warp great, be difficult to guarantee constructor safety, if adopt earth pressure balance shield machine excavation to carry out the push pipe construction, difficult processing when the excavation face meets great barrier, because of when groundwater level is higher again, screw conveyer goes out mud mouth probably erupts, will bring great potential safety hazard for the construction. In addition, the cutter head of the existing shield machine is difficult to cut the pebble stratum with large particle size.

Disclosure of Invention

The technical problem to be solved by the invention is to provide an efficient and safe power channel structure capable of passing through an existing highway and a subway line.

The invention aims to solve the technical problem of providing a slurry balance shield machine capable of being safely constructed and a top pipe tunneling construction method using the slurry balance shield machine.

To achieve the above object, according to one aspect of the present invention, there is provided a power passage structure crossing a subway line. The power channel structure crossing the subway line comprises an originating well, a receiving well and a pipe jacking section for connecting the originating well and the receiving well, wherein the pipe jacking section comprises concrete pipe sections connected end to end; the starting well and the receiving well are respectively positioned on two sides of the existing subway line; the distance between the starting well and the existing subway line is greater than that between the receiving well and the existing subway line; the road between the receiving well and the starting well comprises an existing road and undisturbed soil bodies on two sides of the existing road; the top pipe section is positioned between the road surface and the existing subway line; the structure also comprises a reinforcing structure; the reinforcing structure comprises a first reinforcing structure at least arranged in an undisturbed soil body between the starting well and the existing road and a second reinforcing structure positioned outside the concrete pipe section.

Starting pipe jacking construction from an originating well far away from a subway line, reserving a certain distance before penetrating through a subway culvert to observe whether each index condition of the pipe jacking penetrating through the stratum is normal, and then continuously correcting, such as revising concentration ratio of muddy water and the like; through setting up reinforced structure, can prevent that the road surface from subsiding the deformation. Through setting up reinforced structure in the original state soil body, can ensure to avoid causing the influence to the operation of existing highway under the prerequisite of consolidating the effect. Through reinforcing in the direction of height subregion, can practice thrift the engineering time under the prerequisite of guaranteeing to reinforce the effect. Therefore, the power channel structure crossing the subway line has the advantages of simple and safe structure and high-efficiency construction. The invention is not only suitable for the construction of power channels, but also suitable for the construction of other pipelines needing to be dug in the dark.

Furthermore, the distance between the bottom of the pipe jacking section and the top of the existing subway line is more than or equal to 6 meters. Therefore, the safe operation of the subway line cannot be influenced.

Furthermore, the distance between the top of the pipe jacking section and the bottom of a small three-way pipe below the road surface is more than or equal to 0.5 m, and the small three-way pipe is any of a water pipe, an electric power pipeline, a communication pipeline and a gas pipeline. Therefore, the influence on the life of the neighboring residents is avoided while the safety of construction is ensured.

Furthermore, the top pipe section penetrates through the river channel downwards, and the distance between the top of the top pipe section and the bottom of the river channel is more than or equal to 1 meter. From this, avoid causing the disturbance to the river course structure when guaranteeing construction safety nature.

Further, the originating well is rectangular in cross-section; the cross section of the receiving well is circular. The rectangular starting well can fully utilize the space in the well, and the flat wall surface is convenient for arranging a rear seat wall; the round receiving well has better stress performance than a rectangle and is more suitable for a working well with deeper covering soil.

Further, the first reinforcing structure is at least arranged in an undisturbed soil body of 20 meters with the starting well as a starting point; the depth of the first reinforcing structure is more than or equal to 3 meters, and the width of the first reinforcing structure is more than or equal to 5 meters. This ensures a superior reinforcing effect.

Further, the first reinforcing structure comprises grouting holes distributed vertically and slurry filled in the grouting holes. Preferably, the grouting holes are arranged in a 1-by-1-meter quincunx shape, the distribution amount and the distribution intervals of the grouting holes are proper, and the reinforcing effect of the obtained first reinforcing structure is better.

Further, the second reinforcing structure is at least arranged in a soil body 1 m outside the concrete pipe section. Therefore, the reinforcing effect is good, and the construction difficulty is small.

Further, the second reinforcing structure comprises muddy water and cement mortar filled in a soil body outside the concrete pipe joint.

Further, the burial depth of the top pipe section is gradually reduced from the originating well to the receiving well. This promotes discharge of muddy water generated in pipe jacking work.

Further, the slope of the top pipe section is 0.2-0.5%. Therefore, the pipe jacking tunneling and the muddy water discharge are convenient.

And furthermore, precipitation wells are arranged on the two sides of the power channel circuit of the originating well and the receiving well. The dewatering well can reduce the underground water level and make the pressure of the underground water reach a controllable range, thereby ensuring the construction safety.

Furthermore, the joint of the adjacent concrete pipe sections comprises a first sealing layer, a filling plate, a water stop strip, a second sealing layer and a rigid sleeve ring which are sequentially arranged from inside to outside, and a sealing ring is arranged between the steel sleeve ring and the concrete pipe section socket.

In order to achieve the aim, according to another aspect of the invention, the invention also provides a slurry balance shield machine and a pipe jacking construction method using the same. The method comprises the following specific steps:

the slurry balance shield machine comprises a rotatable cutter head and a cutting mechanism, wherein the cutter head is provided with a conical surface and a propelling surface, the cross section of the conical surface is gradually reduced, and a feeding hole is formed in the propelling surface; the cutting mechanism comprises a first cutting assembly and a second cutting assembly; the first cutting assembly comprises a cutter arranged on the cutter head, and the cutter comprises a hob and a scraper; the hob comprises a first hob distributed on the propelling surface and a second hob annularly distributed on the conical surface; the scrapers comprise a first scraper distributed on the feed inlet, a second scraper distributed on the pushing surface and a third scraper annularly distributed on the conical surface; the second cutting assembly includes a twist leg supporting the cutter head and rotating and a disc forming a crushing gap with the twist leg.

The crushed stone obtained by the crushing (primary crushing) of the cutter can enter the crushing bin from the feeding hole and further enter the crushing gap so as to be secondarily crushed under the mutual rotary shearing of the twisting leg and the disc body, so that the crushing effect is good due to the two-time crushing, and the crushed stone can be crushed into larger crushed stone during the primary crushing, thereby reducing the abrasion of the cutter. By arranging the conical surface and the cutters distributed along the annular direction of the conical surface, the tunnel face can be cut in multiple directions, and the tunneling speed is obviously improved. The cutter head in a specific shape and the first cutting assembly in a special arrangement can enable the cutter to be in full contact with the tunnel face, so that the tunnel face is cut into more uniform broken stones.

With the rotation of the cutter head, the hob revolves around the central shaft of the cutter head and rotates around the axis of the hob, and under the action of the thrust and the torque of the cutter head, the hob cuts a series of circular grooves on the face of the hob. When the thrust exceeds the strength of the soil and the stone, the soil and the stone below the cutter point of the hob are crushed, the cutter point penetrates through the soil and the stone to form a crushing area and radial cracks, and the cracks between the adjacent hobs extend and are communicated with each other; the cutting edge is continuously extruded until the extrusion force per se is equal to the strength of the rock, and then the rock is extruded inwards, so that the earth and the rock are cracked and spread to the periphery to form broken stones to collapse; therefore, the hob can gradually crush the soil and the stones into smaller broken stones, so that the broken stones can enter the crushing bin to be secondarily crushed into particles with conveyable particle sizes through the crushing gap. And the scraper can be used for further crushing larger crushed stones and scraping the crushed stones into the feeding hole.

Therefore, the slurry balance shield machine is simple in structure and particularly suitable for cutting a large-particle-size pebble stratum, wherein the particle size of pebbles can reach 500 millimeters or even higher.

Further, the opening rate of the cutter head is 25-35%. Thereby, the feeding speed of the feeding hole is suitable for the cutting speed of the cutter.

Furthermore, the number of the feed inlets is four, and the feed inlets are symmetrically distributed with the center of the propelling surface; the feed port extends to the tail part of the conical surface; the feed inlet is of a special-shaped structure. Therefore, the soil and stones crushed at one time can pass through the feeding hole quickly, and the tunneling speed is improved.

Further, the width of the feed inlet is gradually increased from the inner part of the pushing surface to the tail part of the conical surface. Through verification, the soil and stone crushing degree close to the center of the cutter head is usually higher than the soil and stone crushing degree far away from the center of the cutter head, so that the discharging speed of the feeding port can be increased, and more cutter mounting areas can be reserved.

Furthermore, the four feed inlets are provided with hole walls which are parallel to each other and extend to the tail part of the conical surface for mounting the first scraper. Therefore, the soil and stones can be further crushed by the first scraper and can quickly pass through the feed inlet under the scraping and coating action of the first scraper.

Furthermore, the first scrapers on each feed inlet are distributed at intervals and distributed to the tail part of the conical surface. From this, promote broken degree to further promote row material efficiency.

Furthermore, at least most of the first scrapers of the two adjacent feed inlets are distributed in a staggered manner. Therefore, the soil and the stones are fully contacted with the tunnel face, so that the soil and the stones are crushed more uniformly.

Further, the cutting direction of the second hob is perpendicular to the conical surface; the second hob is a double-edged hob.

Further, the first hob cutter comprises a combined hob cutter which is positioned in the center of the propelling surface and the cutting direction of the combined hob cutter is perpendicular to the propelling surface, and discrete hob cutters which are positioned on the left side, the right side, the upper side and the lower side of the combined hob cutter. Therefore, the first hob can fully exert the crushing effect.

Furthermore, the discrete hobs positioned at the left side and the right side of the combined hob are distributed in a staggered manner; and the discrete hobs positioned on the upper side and the lower side of the combined hob are distributed in a staggered manner. Therefore, the first hob can be fully contacted with the soil and the stones on the tunnel face, so that the soil and the stones are crushed into more uniform broken stones.

Furthermore, the cutting direction of part of the discrete hobs is not vertical to the propelling surface; the cutting direction of part of the discrete hobs is vertical to the propelling surface and vertical or parallel to the cutting direction of the combined hob; the cutting direction of some of the discrete hob cutters is perpendicular to the plane of thrust and neither perpendicular nor parallel to the cutting direction of the combined hob cutter. Therefore, the crushed stone on the tunnel face is cut in multiple directions, and the formation of smaller crushed stone is facilitated.

Furthermore, the combined hob is formed by connecting single-edge hobs in series; the discrete hob is a double-edged hob. Therefore, larger cutting force can be generated at the center, and the soil and the stone on the tunnel face are quickly crushed.

Further, the disk body is conical and protrudes towards the tail of the shield tunneling machine. Therefore, the conical disc body can form a crushing bin which has a large space and can store crushed stones once, and the tunneling speed is improved.

Furthermore, at least the lower part of the disc body is provided with a discharge opening with the size larger than or equal to the width of the crushing gap, and a muddy water bin is arranged behind the discharge opening. When the disc body does not rotate relative to the twisting legs, the discharge opening is only arranged at the lower part of the disc body, so that the crushed stones can be fully rotated and sheared in the descending process.

Further, the method also comprises the following steps:

the first grouting mechanism conveys the muddy water to the tunnel face through a first muddy water hole in the disc body and a feed inlet in the cutter disc;

and the second grouting mechanism injects muddy water into a muddy water bin filled with crushed stones obtained by crushing the second cutting assembly.

And the third grouting mechanism conveys muddy water to the outside of the shield tunneling machine body through a second muddy water hole in the shield tunneling machine body.

The muddy water injected into the tunnel face through the first grouting mechanism can balance and stabilize the underground water pressure and the soil pressure of the tunnel face, and is more beneficial to cutting of the tunnel face; the muddy water injected into the muddy water bin through the second grouting mechanism is stirred with the cut crushed stones and the soil body and then is conveniently discharged through the mud discharge valve; the mud water injected into the periphery of the shield tunneling machine through the third grouting mechanism can enable the super-excavation surface to be filled with mud, the mud penetrates into a soil body and forms a mud sleeve, so that the shield tunneling machine and the concrete pipeline can be suspended on the mud, and therefore tunneling resistance is greatly reduced. Preferably, when thick muddy water with the relative muddy water concentration of more than or equal to 1.4 is adopted for grouting, the pressure of a soil body can be balanced to the maximum extent, the discharge of solid-liquid mixtures in a muddy water bin is facilitated, and the tunneling resistance is reduced.

The pipe jacking tunneling construction method comprises the step of adopting the slurry balance shield machine.

Further, the method is used for pipe jacking segment construction in the power channel connecting the originating well and the receiving well. The power channel structure is preferably the power channel structure crossing the subway line, so that rapid construction can be realized, and the disturbance to the operation of subways and highways and the surrounding soil body is reduced.

The invention is further described with reference to the following figures and detailed description. Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to assist in understanding the invention, and are included to explain the invention and their equivalents and not limit it unduly. In the drawings:

fig. 1 is a schematic view of a power passage structure crossing a subway line according to embodiment 1 of the present invention.

Fig. 2 is a schematic view of a reinforcing structure in an electric power passage structure crossing a subway line in embodiment 1 of the present invention.

Fig. 3 is a schematic view of a grouting hole in an electric power passage structure crossing a subway line according to embodiment 1 of the present invention.

Fig. 4 is a schematic view of a concrete pipe joint connection in an electric power passage structure crossing a subway line according to embodiment 1 of the present invention.

Fig. 5 is a schematic view of a cutter head in a slurry balance shield machine according to embodiment 2 of the present invention.

FIG. 6 is a schematic view of a second cutting assembly in a slurry balance shield tunneling machine according to embodiment 2 of the present invention.

Fig. 7 is a schematic view of a disc body of a slurry balance shield machine according to embodiment 2 of the present invention.

The relevant references in the above figures are:

110-originating well, 120-receiving well, 210-existing subway line, 220-existing road, 230-undisturbed soil, 240-river channel, 300-top pipe section, 310-concrete pipe section, 311-spigot, 312-mud hole, 313-check valve, 510-first sealing layer, 520-filling plate, 530-water stop bar, 540-second sealing layer, 550-rigid collar, 560-sealing ring, 410-first reinforcing structure, 411-mud hole, 420-second reinforcing structure, 500-cutterhead, 510-conical surface, 520-propelling surface, 530-feed inlet, 540-twisting leg, 550-crushing bin, 551-crushing gap, 611-combined hob, 612-discrete hob, 620-second hob, 710-first scraper, 720-second scraper, 730-third scraper, 800-disc body, 810-discharge outlet, 820-first muddy water hole and 830-muddy water bin.

Detailed Description

The invention will be described more fully hereinafter with reference to the accompanying drawings. Those skilled in the art will be able to implement the invention based on these teachings. Before the present invention is described in detail with reference to the accompanying drawings, it is to be noted that:

the technical solutions and features provided in the present invention in the respective sections including the following description may be combined with each other without conflict.

Moreover, the embodiments of the present invention described in the following description are generally only some embodiments of the present invention, and not all embodiments. Therefore, all other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without any creative effort shall fall within the protection scope of the present invention.

With respect to terms and units in the present invention. The terms "comprising," "having," and any variations thereof in the description and claims of this invention and the related sections are intended to cover non-exclusive inclusions.

Example 1

The power passageway structure across a subway line as shown in fig. 1 comprises an originating well 110, a receiving well 120, a top pipe section 300 connecting originating well 110 and receiving well 120, and a reinforced structure, said top pipe section 300 comprising concrete pipe sections 310 connected end to end.

The originating shaft 110 and the receiving shaft 120 are respectively located at two sides of an existing subway line 210, and the distance between the originating shaft 110 and the existing subway line 210 is greater than that between the receiving shaft 120 and the existing subway line 210; the road between the receiving well 120 and the originating well 110 includes an existing road 220 and undisturbed soil 230 on both sides of the existing road 220; the originating well 110 is rectangular in cross-section; the receiving well 120 is circular in cross-section.

The top pipe section 300 has a decreasing depth from the originating well 110 to the receiving well 120 with a slope of 0.3%.

The top pipe section 300 is located between the road surface and the existing subway line 210; the distance between the bottom of the top pipe section 300 and the top of the existing subway line 210 is more than or equal to 6 meters; the distance between the top of the top pipe section 300 and the bottom of a small three-way pipe below a road surface is more than or equal to 0.5 m, and the small three-way pipe is any of a water pipe, an electric power pipeline, a communication pipeline and a gas pipeline. The top pipe section 300 penetrates through the river channel 240, and the distance between the top of the top pipe section 300 and the bottom of the river channel 240 is more than or equal to 1 meter.

The reinforcing structure includes a first reinforcing structure 410 provided in 20 m undisturbed soil 230 starting from the originating well 110 and a second reinforcing structure 420 located outside the concrete pipe section 310. As shown in FIG. 2, the first reinforcing structure 410 has a depth of 3 meters or more and a width of 5 meters or more; the first reinforcing structure 410 includes vertically-distributed grouting holes 411 and grout filled in the grouting holes 411. As shown in fig. 3, the injection holes 411 are arranged in a 1 × 1 m quincunx pattern. The second reinforcement structure 420 is at least arranged in the soil body 1 m outside the concrete pipe joint 310; the second reinforcing structure 420 includes muddy water and cement mortar filled in the soil body outside the concrete pipe joint 310.

Precipitation wells are arranged on two sides of the power channel circuit of the originating well 110 and the receiving well 120, and no precipitation well is arranged in the range of the top pipe section 300.

As shown in fig. 4, the joint of adjacent concrete pipe sections 310 includes a first sealing layer 510, a filling plate 520, a water stop strip 530, a second sealing layer 540 and a steel collar 550, which are sequentially arranged from inside to outside, and a sealing ring 560 is arranged between the steel collar and the socket 311 of the concrete pipe section 310. The filling plate 520 is a plywood, the sealing ring 560 is a sliding rubber ring, the outer surface of the steel bushing ring is anticorrosive by thick paste type epoxy coal tar, and the first sealing layer 510 and the second sealing layer 540 are made of polyurethane sealing paste.

Example 2

The slurry balance shield machine shown in fig. 5-7 comprises a rotatable cutter head 500, a cutting mechanism, a twisting leg 540, a disc body 800, a first grouting mechanism, a second grouting mechanism and a third grouting mechanism, wherein a crushing bin 550 is formed between the disc body 800 and the cutter head 500, and a slurry bin 830 is arranged behind the disc body 800.

As shown in fig. 5, the cutter head 500 has a tapered surface 510 with a gradually decreasing cross section and a pushing surface 520 matching with the tunnel surface, the pushing surface 520 is provided with four feed ports 530, the opening ratio of the cutter head 500 is 29%, and the feed ports 530 are symmetrically distributed with the center of the pushing surface 520; the feed port 530 extends to the tail of the conical surface 510; the width of the feed inlet 530 gradually increases from the inside of the pushing surface 520 to the tail of the tapered surface 510;

the cutting mechanism comprises a first cutting assembly and a second cutting assembly;

the first cutting assembly comprises a cutter arranged on the cutter head 500, and the cutter comprises a hob and a scraper;

the roller cutters include a first roller cutter distributed on the pusher surface 520 and a second roller cutter 620 distributed annularly on the conical surface 510.

The first roller cutters include a combination roller cutter 611 located at the center of the propelling surface 520 and cutting perpendicular to the propelling surface 520, and discrete roller cutters 612 located on the left and right sides and the top and bottom sides of the combination roller cutter 611. The discrete hobs 612 on the left side and the right side of the combined hob 611 are distributed in a staggered manner; the discrete hobs 612 on the upper side and the lower side of the combined hob 611 are distributed in a staggered manner; the cutting direction of some of the discrete roller cutters 612 is not perpendicular to the plane of thrust 520; the cutting direction of some of the discrete roller cutters 612 is perpendicular to the pushing surface 520 and perpendicular or parallel to the cutting direction of the combination roller cutter 611; the cutting direction of some of the discrete roller cutters 612 is perpendicular to the pushing surface 520 and is neither perpendicular nor parallel to the cutting direction of the combination roller cutters 611.

The combined hob 611 is formed by connecting single-edged hobs in series; the discrete hob 612 is a double-edged hob.

The cutting direction of the second hob 620 is perpendicular to the conical surface 510; the second roller cutters 620 are both double-edged roller cutters.

The scrapers include a first scraper 710 distributed at the feed inlet 530, a second scraper 720 distributed on the pushing surface 520, and a third scraper 730 annularly distributed on the tapered surface 510; the four feed ports 530 have hole walls parallel to each other and extending to the tail of the tapered surface 510 for the first scraper 710 to mount; the first scrapers 710 on each feed inlet 530 are distributed at intervals and distributed to the tail part of the conical surface 510; at least most of the first scrapers 710 of the two adjacent feed ports 530 are arranged in a staggered manner.

As shown in fig. 6-7, the second cutting assembly includes a twist leg 540 that supports the impeller 500 and rotates, and a disc 800 that forms a crushing gap 551 with the twist leg 540. The disc body 800 is conical and protrudes towards the tail of the shield tunneling machine; the lower part of the disc 800 is provided with a discharge opening 810 having a size larger than the width of the crushing gap 551, the width of the crushing gap 551 being 30 mm, the discharge opening 810 being circular, the diameter of the discharge opening 810 being 70 mm.

The first grouting mechanism conveys muddy water to the tunnel face through the first muddy water hole 820 on the disc body 800 and the feed inlet 530 on the cutter head 500;

the second grouting mechanism injects muddy water into a muddy water bin 830 containing crushed stone obtained by crushing the second cutting assembly.

The muddy water bin 830 is internally provided with a pressure detection mechanism and a mud discharge valve, and when the pressure in the muddy water bin 830 rises to a certain value, the concentrated muddy water and the crushed stones are discharged through the mud discharge valve.

The top pipe tunneling construction method using the slurry balance shield machine of the embodiment 2 is very suitable for the top pipe section 300 construction in the embodiment 1. The method specifically comprises the following steps:

(1) dewatering well construction and reinforced structure construction;

(2) originating well 110 and working well construction;

(3) the slurry balance shield machine of the embodiment 2 is adopted to start from a starting well 110 until receiving at a receiving well 120;

besides adopting the third grouting mechanism to perform grouting on the outside of the shield machine body, the hose is also adopted to perform slurry grouting on the outside of the concrete pipe joint 310. Specifically, 3 grouting holes 312 matched with a hose are arranged on a socket 311 of each concrete pipe section 310, the 3 grouting holes 312 are annularly arranged at 120 degrees, the aperture of each grouting hole 312 is 20 mm, and a one-way valve 313 is arranged in each grouting hole 312.

The diameter of the cutter head 500 of the shield tunneling machine is 2.2 meters, and the outer diameters of the shield tunneling machine body and the concrete pipe joint 310 behind the cutter head 500 are 2 meters, so that an overexcavation surface can be formed outside the shield tunneling machine body and the concrete pipe joint 310 in the tunneling process. The muddy water injected into the outer portion of the shield tunneling machine pipe body and the outer portion of the concrete pipe joint 310 can enable the super-excavation surface to be filled with mud, the mud penetrates into a soil body and forms a mud sleeve, and the thickness of the mud sleeve is 1-2 cm. In order to reduce the deformation of the surrounding rock at the upper part, the grouting pressure is controlled to be 0.1-0.2 MPa.

After the completion of the excavation, the slurry in the formed slurry sheath needs to be replaced. High-pressure cement mortar with the grade not less than M10 is also injected through the grouting holes 312 on the spigots 311 of the concrete pipe joints 310 to replace the mud.

For example, in a power channel constructed in a metropolitan lamb area in Sichuan province, a fourth subway line is penetrated upwards, a Guanghua avenue is penetrated downwards, the length is 99 meters, the stratum is rich in pebbles with large particle size (more than 180 millimeters), and the traditional pipe jacking construction method and the shield machine cannot be used for rapidly completing the construction in the early stage of ensuring the safety.

By adopting the pipe-jacking tunneling construction method, the safe completion can be completed within 40 days finally. In the adopted slurry balance shield machine, the hob is made of high-strength alloy steel, and the hardness reaches more than Rockwell hardness HRC 60. The muddy water adopts water in a mass ratio: bentonite is 1:1.4 (i.e. relative concentration of 1.4) thixotropic mud. The total frictional resistance required to be overcome by the whole top pipe section 300 is 9499kN calculated, and the allowable jacking force 12480kN of the concrete pipe section 310 is not exceeded, so that the tunneling process is safe and reliable.

The constructed pipe jacking section 300 is as follows:

the bottom elevation of the top pipe section 300 is about 518 meters, the top elevation of the top pipe section 300 is about 520.2 meters, the ground elevation is about 525.5 meters, and the underground water level is 522.71 meters;

the distance between the top of the top pipe section 300 and the bottom of the river channel 240 is about 1.5 meters, the distance between the bottom of the top pipe section 300 and the top of the existing subway line 210 is about 6 meters, and the distances between the top of the top pipe section 300 and the small three lines of water pipes, electric power, communication, fuel gas and the like are all more than 70 centimeters;

the first reinforcement structure 410 has a depth of 3.5 m and a width of 7 m, and is used as a grouting pipe

The grouting material of the sleeve valve pipe is cement-water glass slurry, the volume ratio of cement to water glass is 1:1, and the water cement ratio of cement slurry is 1: 1;

the second reinforcement structure 420 is disposed in the soil mass 1 meter outside the concrete pipe section 310.

The contents of the present invention have been explained above. Those skilled in the art will be able to implement the invention based on these teachings. All other embodiments, which can be derived by a person skilled in the art from the above description without inventive step, shall fall within the scope of protection of the present invention.

Claims

1. Slurry balance shield constructs machine, includes rotatable blade disc (500) and cutting mechanism, its characterized in that:

the cutter head (500) is provided with a conical surface (510) with a gradually-reduced cross section and a pushing surface (520) matched with the tunnel face, and a feeding hole (530) is formed in the pushing surface (520);

the first cutting assembly comprises a cutter arranged on the cutter head (500), and the cutter comprises a hob and a scraper; the roller cutters comprise a first roller cutter distributed on the propelling surface (520) and a second roller cutter (620) annularly distributed on the conical surface (510); the scrapers comprise a first scraper (710) distributed on the feed inlet (530), a second scraper (720) distributed on the pushing surface (520) and a third scraper (730) annularly distributed on the conical surface (510);

the second cutting assembly includes a twist leg (540) supporting the impeller (500) and rotating and a disc (800) forming a crushing gap (551) with the twist leg (540).

2. The mud balance shield machine of claim 1, wherein: the opening rate of the cutter head (500) is 25-35%; the number of the feed inlets (530) is four, and the feed inlets are symmetrically distributed with the center of the propelling surface (520); the feed port (530) extends to the tail part of the conical surface (510); the feed inlet (530) is of a special-shaped structure.

3. The mud balance shield machine of claim 2, wherein: the width of the feed port (530) is gradually increased from the inner part of the propelling surface (520) to the tail part of the conical surface (510); the four feed ports (530) have parallel bore walls extending to the end of the tapered surface (510) for receiving the first scraper (710).

4. The mud balance shield machine of claim 3, wherein: the first scrapers (710) on each feed port (530) are distributed at intervals and distributed to the tail part of the conical surface (510); at least most of the first scrapers (710) of the two adjacent feed inlets (530) are distributed in a staggered manner.

5. The mud balance shield machine of claim 1, wherein: the first hob cutter comprises a combined hob cutter (611) which is positioned in the center of the propelling surface (520) and the cutting direction of the combined hob cutter is vertical to the propelling surface (520), and discrete hob cutters (612) which are positioned on the left side, the right side, the upper side and the lower side of the combined hob cutter (611); the cutting direction of the second hob (620) is perpendicular to the conical surface (510); the second hob (620) is a double-edged hob.

6. The mud balance shield machine of claim 5, wherein: the discrete hobs (612) positioned at the left side and the right side of the combined hob (611) are distributed in a staggered way; the discrete hobs (612) positioned at the upper side and the lower side of the combined hob (611) are distributed in a staggered way; the cutting direction of part of the discrete hobs (612) is not vertical to the propelling surface (520); the cutting direction of the partial discrete hob (612) is perpendicular to the pushing surface (520) and perpendicular or parallel to the cutting direction of the combined hob (611); the cutting direction of the partial discrete hob (612) is perpendicular to the pushing surface (520) and is neither perpendicular nor parallel to the cutting direction of the combined hob (611); the combined hob (611) is formed by connecting single-edge hobs in series; the discrete hob (612) is a double-edged hob.

7. The mud balance shield machine of claim 1, wherein: the disc body (800) is conical and protrudes towards the tail of the shield tunneling machine; at least the lower part of the disc body (800) is provided with a discharge opening (810) with a size larger than or equal to the width of the crushing gap (551).

8. The mud balance shield machine of claim 1, wherein: further comprising:

the first grouting mechanism conveys muddy water to the tunnel face through a first muddy water hole (820) on the disc body (800) and a feeding hole (530) on the cutter head (500);

and the second grouting mechanism injects muddy water into a muddy water bin (830) filled with crushed stone obtained by crushing the second cutting assembly.

9. The pipe-jacking tunneling construction method is characterized by comprising the following steps: comprising the use of a slurry balance shield machine according to any one of claims 1 to 8.

10. The pipe-jacking tunneling construction method according to claim 9, characterized by: construction of a pipe jacking section (300) for connecting an originating well (110) and a receiving well (120) in a power channel; the method also comprises the steps of injecting muddy water outside the concrete pipe joint (310) in the tunneling process; and further comprises the step of injecting cement outside the concrete pipe joint (310) after the tunneling is finished.