CN116856949A - Maintenance and re-pushing construction method for river bottom ultra-deep high water pressure shield - Google Patents
Maintenance and re-pushing construction method for river bottom ultra-deep high water pressure shield Download PDFInfo
- Publication number
- CN116856949A CN116856949A CN202310647761.5A CN202310647761A CN116856949A CN 116856949 A CN116856949 A CN 116856949A CN 202310647761 A CN202310647761 A CN 202310647761A CN 116856949 A CN116856949 A CN 116856949A
- Authority
- CN
- China
- Prior art keywords
- shield
- open caisson
- wall
- construction
- freezing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 102
- 238000010276 construction Methods 0.000 title claims abstract description 72
- 238000012423 maintenance Methods 0.000 title claims abstract description 19
- 239000002689 soil Substances 0.000 claims abstract description 55
- 238000000034 method Methods 0.000 claims abstract description 37
- 230000005641 tunneling Effects 0.000 claims abstract description 20
- 230000008014 freezing Effects 0.000 claims description 73
- 238000007710 freezing Methods 0.000 claims description 73
- 229910000831 Steel Inorganic materials 0.000 claims description 36
- 239000010959 steel Substances 0.000 claims description 36
- 239000004567 concrete Substances 0.000 claims description 14
- 238000009412 basement excavation Methods 0.000 claims description 12
- 238000005520 cutting process Methods 0.000 claims description 12
- 230000002787 reinforcement Effects 0.000 claims description 12
- 238000013461 design Methods 0.000 claims description 6
- 238000007789 sealing Methods 0.000 claims description 6
- 238000003466 welding Methods 0.000 claims description 6
- 239000000463 material Substances 0.000 claims description 5
- 239000004570 mortar (masonry) Substances 0.000 claims description 5
- 239000004576 sand Substances 0.000 claims description 4
- 230000009194 climbing Effects 0.000 claims description 3
- 238000005553 drilling Methods 0.000 claims description 3
- 238000002513 implantation Methods 0.000 claims description 3
- 238000009434 installation Methods 0.000 claims description 3
- 230000001360 synchronised effect Effects 0.000 claims description 2
- 230000000977 initiatory effect Effects 0.000 abstract 1
- 230000003014 reinforcing effect Effects 0.000 description 7
- 230000000694 effects Effects 0.000 description 6
- 238000011065 in-situ storage Methods 0.000 description 5
- 239000011150 reinforced concrete Substances 0.000 description 5
- 238000003756 stirring Methods 0.000 description 5
- 238000005452 bending Methods 0.000 description 4
- 239000011211 glass fiber reinforced concrete Substances 0.000 description 4
- 230000008439 repair process Effects 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 238000005266 casting Methods 0.000 description 2
- 230000011218 segmentation Effects 0.000 description 2
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 1
- 229910001294 Reinforcing steel Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000005422 blasting Methods 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 239000012267 brine Substances 0.000 description 1
- 235000011089 carbon dioxide Nutrition 0.000 description 1
- 239000000306 component Substances 0.000 description 1
- 239000008358 core component Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000011152 fibreglass Substances 0.000 description 1
- 238000007667 floating Methods 0.000 description 1
- 238000009432 framing Methods 0.000 description 1
- 239000003673 groundwater Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000009417 prefabrication Methods 0.000 description 1
- 238000004080 punching Methods 0.000 description 1
- 238000005067 remediation Methods 0.000 description 1
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000002352 surface water Substances 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
- E21D9/06—Making by using a driving shield, i.e. advanced by pushing means bearing against the already placed lining
- E21D9/08—Making by using a driving shield, i.e. advanced by pushing means bearing against the already placed lining with additional boring or cutting means other than the conventional cutting edge of the shield
- E21D9/087—Making by using a driving shield, i.e. advanced by pushing means bearing against the already placed lining with additional boring or cutting means other than the conventional cutting edge of the shield with a rotary drilling-head cutting simultaneously the whole cross-section, i.e. full-face machines
- E21D9/0873—Making by using a driving shield, i.e. advanced by pushing means bearing against the already placed lining with additional boring or cutting means other than the conventional cutting edge of the shield with a rotary drilling-head cutting simultaneously the whole cross-section, i.e. full-face machines the shield being provided with devices for lining the tunnel, e.g. shuttering
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D23/00—Caissons; Construction or placing of caissons
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D23/00—Caissons; Construction or placing of caissons
- E02D23/08—Lowering or sinking caissons
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
- E21D11/04—Lining with building materials
- E21D11/08—Lining with building materials with preformed concrete slabs
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
- E21D11/04—Lining with building materials
- E21D11/10—Lining with building materials with concrete cast in situ; Shuttering also lost shutterings, e.g. made of blocks, of metal plates or other equipment adapted therefor
- E21D11/105—Transport or application of concrete specially adapted for the lining of tunnels or galleries ; Backfilling the space between main building element and the surrounding rock, e.g. with concrete
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
- E21D11/38—Waterproofing; Heat insulating; Soundproofing; Electric insulating
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
- E21D9/001—Improving soil or rock, e.g. by freezing; Injections
Abstract
The invention provides a maintenance and re-pushing construction method for a river bottom ultra-deep high water pressure shield, which relates to the technical field of shield construction, when a shield machine is forced to stop due to equipment faults in the tunneling process in the river, particularly when a cutter head is required to be disassembled or a bearing is taken out to maintain similar serious faults, a sunk well is sunk to a designed elevation, soil bodies between the sunk well and the cutter head and around the shield are frozen and reinforced from the sunk well to the shield direction, a tunnel portal is broken, frozen soil in front of the cutter head is removed by adopting a hidden digging method, shi Zuohuan is lined, and the shield machine is pushed from the annular lining to the inner space of the lining to the sunk well for maintenance and secondary initiation; the invention can provide a safe working space for shield equipment maintenance in a water bottom environment with the water depth of more than 20 meters, so that the shield equipment can be driven again, and the tunnel can be constructed continuously.
Description
Technical Field
The invention relates to the technical field of shield construction, in particular to a maintenance and re-pushing construction method for a river bottom ultra-deep high water pressure shield.
Background
The shield method construction has the advantages of high industrialization level, small environmental disturbance, no influence on ground activity and the like, and along with the development of shield tunnel construction technology and mechanical equipment, the advantages of the shield tunnel are more obvious, and more tunnels are considered to be built by the shield method. The construction trend of the shield tunnel in China is developed from a single soft soil stratum to a complex stratum, from a large diameter to an ultra-large diameter, from medium water pressure to high water pressure and ultra-high water pressure, from short-distance tunneling to long-distance and ultra-long-distance tunneling, and the difficulty of construction is increased.
The shield machine is mainly formed by combining mechanical equipment such as a shield shell, a cutter head system, a driving system, a hydraulic system, a duct piece splicing machine, a pipeline system, a rear matched trolley and the like, and faults of the machine in the using process are difficult to avoid. The assembly machine, the pipeline and the like can be directly maintained from the inside when faults occur, the cutter is severely worn, and the cutter can be maintained by replacing the cutter with pressure or replacing the cutter with normal pressure, so that the prior art is relatively mature. However, once the main drive and the main bearing have serious faults, hundreds of tons of main drive are required to be disassembled for maintenance, and repair work cannot be carried out in a tunnel. The main drive and the main bearing are core components for the rotation of the shield cutterhead, the cutterhead cannot rotate after being damaged, the shield machine can only be forced to stop, and particularly for an underwater shield tunnel crossing the river and the sea, engineering failure can be caused.
At present, there are some engineering cases that shields are trapped in the ground due to equipment faults and cannot be excavated or maintained, and the engineering cases comprise the shields trapped in the stratum of underwater, particularly deep water areas with the depth of more than 20m, and no better solution exists at present. When the shield is trapped in a deep water area, the cutter head of the shield machine cannot rotate and cannot cut a soil layer under the forced shutdown state of the shield machine caused by main bearings, main drives or other faults, so that the shield machine cannot be pushed forward. The shield machine is generally disassembled for maintenance. Firstly, the stratum has no space, the main drive is more than 500 tons, the inside of the stratum can not provide enough hoisting capacity and replaceable parts for supporting water and soil pressure, the prior art can only carry out maintenance operation through a working well, and the problem that how to ensure that the working well can bear larger water and soil load, can keep stability and has good waterproofness is solved at the bottom of a relatively deep river. Secondly, the working well is not well ridden above the shield machine due to the limitation of the segment behind the shield tail and the shield machine, and if the working well is arranged in front of the cutterhead, how to push the shield machine into the working well is also difficult. And finally, all links need to ensure that the structure can bear water and soil load and has enough water stopping effect so as to avoid water and sand gushing.
Therefore, a feasible repairing and re-pushing scheme is needed to be provided for the situation that the shield machine is stopped and the tunneling working condition cannot be continued due to main driving, main bearing damage or other factors of the shield tunnel under deep water conditions such as river bottom or seabed, and the blank of the prior art is made up.
Disclosure of Invention
The invention aims at solving the problems in the prior art, and overcomes the defects in the prior art, and designs a maintenance and re-pushing construction method for the ultra-deep high water pressure shield at the river bottom.
A maintenance and re-pushing construction method for a river bottom ultra-deep high water pressure shield comprises the following steps:
step 1: sectional prefabricated open caisson;
step 2: setting up a temporary construction platform on the water surface, transporting the first section open caisson to a shield stop position, sinking the first section open caisson in front of a shield cutterhead, and carrying out implantation;
step 3: the sinking well is raised and sunk in sections until the design elevation is reached, the bottom sealing is completed, and a guide rail of the shield tunneling machine is constructed;
step 4: carrying out freezing pipe drilling construction and positive freezing construction on the well wall of the receiving place along the outer ring of the shield shell and in the pre-buried orifice pipe in the range of the portal to form a stable freezing wall;
step 5: cutting off a receiving well wall, chiseling frozen soil to a cutter disc, synchronously applying a circular lining, maintaining the freezing of the residual frozen soil in front of the cutter disc in the range of a tunnel portal in the chiseling process until the length of the residual frozen soil is not more than 2 meters, dismantling a freezing pipe in the range of the tunnel portal, and arranging a sliding rail in the circular lining;
step 6: the shield machine is pushed to the annular lining, simultaneously, tunnel segments are assembled and synchronous grouting is carried out to fill gaps between the tunnel segments and the annular lining until the shield machine completely enters the open caisson, water stopping measures are taken at a receiving portal, freezing construction is stopped, freezing equipment is dismantled, and steel plates are welded at cutting positions of orifice pipes to be sealed;
step 7: disassembling and maintaining the shield machine in the open caisson;
step 8: the inner steel shell at the position of the secondary initial portal is cut off from bottom to top in a layered manner, the open caisson is backfilled synchronously, mortar is backfilled in the range of about 2 meters close to the portal, and soil is backfilled at the rest positions;
step 9: the repaired shield tunneling machine continues tunneling forwards along the route from the backfilled open caisson, and the shield tunneling machine leaves the open caisson after cutting mortar and glass fiber reinforced concrete well walls;
step 10: and removing the open caisson structure in the range above the water bottom.
Preferably, the planar shape of the open caisson is circular, and the net size in the open caisson is as follows to meet the space requirements of shield receiving, secondary starting, maintenance and freezing construction:
wherein: d (D) i Is the diameter of the inner wall of the open caisson; r is (r) T The radius of the shield machine is the maximum value; a is radial residual width which is not less than 2 m; l (L) T The length of the shield machine; b is the longitudinal residual width which is not less than 3 meters.
It is further preferred that the open caisson is manufactured in sections, the height of the first section of open caisson is not lower than the water depth, and the total height of the open caisson is calculated as follows to ensure that river water does not enter the open caisson from the top and to provide sufficient construction space at the bottom of the well:
H＝H W +H S +2r T +H O +H B
wherein H is the total height of all well sections of the open caisson; h S The thickness of the earth is covered on the top of the shield; h O The height of the construction space required from the shield bottom to the top of the bottom plate of the open caisson is not less than 1 meter; h B Is the thickness of the bottom plate; h W The height from the river bottom to the top of the open caisson is as follows:
H W ＝H W1 +H W2
wherein H is W1 The height of the water level is from the river bottom to the level of a flood in twenty years; h W2 The height is not less than 2 meters in order to consider the wave climbing and the safety heightening.
Further, the step 2 open caisson wall adopts a combined structure of steel and concrete, the main body is of a concrete structure, the steel shell is arranged at the inner wall, the steel shell is connected with the main body through cylindrical head welding nails, the steel shell is arranged at the inner wall, the waterproof performance is improved, the bearing capacity of the well wall is improved, the safety is improved, and meanwhile, the steel shell is not arranged on the outer wall so as to reduce the workload of subsequent opening and removal.
Preferably, in the step 4, the longitudinal reinforcement length of the segment and the outer freezing wall of the shield shell is calculated according to the following formula so as to meet the soil excavation requirement in the tunnel range between the follow-up cutter head and the wall of the open caisson, and under the special working condition of excavating frozen soil, the freezing wall is required to bear external water and soil load so as to support and form a channel for underground excavation construction, so that the special scene of sealing water of the tunnel, the shield machine and the open caisson is ensured:
l＝l 1 +l T +l 2
wherein l is the longitudinal reinforcement length of the freezing wall outside the segment and the shield shell; l (L) 1 In order to achieve the distance from the longitudinal well wall of the tunnel to the cutter head, the well wall is round, so that the distances between different pile numbers are different; l (L) 2 The length of the shield tail pipe piece wrapped by the freezing wall is not less than 5 meters.
Preferably, the frozen wall in the step 4 needs to wrap the segment behind the shield tail, so that under the condition that the frozen wall is disturbed by pushing of the shield machine, the segment and the frozen wall still keep a cementing state, and the water and sand gushing condition can not occur.
Preferably, step 5 chisels frozen soil to the cutterhead and carries out along vertical segmentation, and segmentation length is no more than 2 meters in order to control the frozen wall and bear the weight of scope and then reduce the excavation risk to in time apply annular lining in inside, supplementary frozen wall bears external load, the construction is to freezing wall's disturbance in the isolated passageway, prevents to freeze wall and shield machine shell cementation and appear pushing away the motionless condition in the sky pushing process, also provides installation space for the slide rail that the sky pushing away the shield behind.
Furthermore, the layering height in the step 8 is not more than 2 meters, so that the safety of dismantling the secondary starting tunnel portal is ensured, and meanwhile, the layering backfilling can better control the backfilling quality.
Preferably, the clear distance between the open caisson and the cutterhead in the step 2 is not less than 2 meters, soil between the open caisson and the cutterhead is reinforced before sinking, and disturbance of sinking construction of the open caisson to a shield machine and a tunnel is avoided.
Further, the thickness of the annular lining in the step 5 is 1.5-2.5 cm when steel materials are adopted, and the thickness of the annular lining is 35-45 cm when concrete materials are adopted, so that the load generated by the weight and the dead weight of the shield machine is borne.
Compared with the prior art, the invention has the beneficial effects that:
the method for maintaining and re-pushing the ultra-deep high water pressure shield at the bottom of the river is designed, when equipment is forced to stop due to equipment faults in the tunneling process of the shield machine, especially when severe faults such as maintenance can be performed only by disassembling a cutter head or taking out a bearing are needed, a safe working space can be provided for maintaining the shield equipment in a water bottom environment with the water depth of more than 20 meters, so that the shield equipment can be re-tunneled, and the tunnel can continue to be constructed.
Drawings
FIG. 1 is a construction flow chart of the present invention;
FIG. 2 is a schematic view of a freeze tube arrangement of the present invention;
FIG. 3 is a schematic view of an embedded orifice tube of the present invention;
FIG. 4 is a rear plan view of the sinking well of the present invention;
FIG. 5 is a longitudinal sectional view of the invention after sinking the open caisson;
FIG. 6 is a plan view of a water stop steel ring provided at a construction receiving portal of the present invention;
FIG. 7 is a longitudinal sectional view of the construction receiving portal of the present invention with a water stop steel ring.
Detailed Description
The maintenance and repeated pushing construction method of the river bottom ultra-deep high water pressure shield is further described in detail below with reference to the accompanying drawings and the specific implementation method.
The patent is based on the current conventional open caisson design and carries out targeted design based on the special working condition that the shield machine is maintained and pushed again under the condition of ultra-deep water pressure at the bottom of the river, and in addition, the open caisson needs to consider disturbance of sinking construction on the shield.
The open caisson in this patent differs somewhat from conventional working wells involved in shield construction. Firstly, the conventional working well is basically an underground continuous wall and is constructed on land, and the invention changes the underground continuous wall into a sunk well aiming at the environment in water. The open caisson in water can ensure better construction quality and stress than the ground wall. Because the underground diaphragm wall is constructed in a framing way, each diaphragm wall is flat, the waterproof performance of the joint is not well guaranteed, and the joint relates to bending moment transmission, so that the waterproof performance and the stress performance of the prefabricated round open caisson are better. The open caisson is prefabricated in a factory, enough roundness can ensure that external water and soil load is converted into axial force, bending moment is reduced, and the horizontal joint is constructed on the water surface, so that the connection quality is high, and the open caisson is waterproof and better in force transmission.
And secondly, the conventional working well is designed to determine a good position according to stratum conditions, ground environment and other factors, the depth of the common working well is shallower, the working well can be constructed in advance, and the shield tunneling machine can be used for pushing in. The shield machine is stopped firstly, and then the open caisson is constructed at a selected position in front of the cutterhead. The construction of the open caisson needs to consider the disturbance influence on the shield machine, the distance between the open caisson and the cutter head needs to be determined, and the soil excavation problem in the tunnel range between the cutter head and the open caisson needs to be solved.
Thirdly, the conventional working well is on land, the control of the peripheral groundwater is easy, the stirring piles, the rotary spraying piles and the freezing reinforcement are adopted at the position of the tunnel portal, the waterproof curtain and the dewatering well can be used as auxiliary materials, and even if the water stopping failure occurs, the water-inrush accident can be caused, and the waterproof curtain can be re-arranged on the ground for remediation. The patent aims at an underwater tunnel, such as a river bottom tunnel with deeper water, the surface water and the underground water are sufficient, the depth of a stirring pile and a jet grouting pile constructed from the water surface is deeper, the quality is not well guaranteed, a waterproof curtain and a dewatering well cannot play a role, and the operations are difficult to develop from the water surface. If water gushes, the water is difficult to treat, so that the sunk well with better water stopping performance is adopted.
And fourthly, the conventional freezing construction can be generally performed from the ground, a freezing pipe does not need to be arranged on the wall of a working well in an opening mode, soil in front of a tunnel gate is frozen and reinforced before a shield machine arrives, and the construction is convenient. Here, since the shield machine is already stopped, the freezing construction can be performed from the water surface if the problem of the water surface construction space is not considered on the upper side and the both sides of the tunnel, but the freezing pipe directly under the tunnel cannot be installed from the water surface. It is only considered to lay the freezing pipe from the inside of the working well, and it is then involved how the freezing pipe is arranged and how the freezing pipe is constructed on the wall of the well with a thickness of about 2 meters. The effect of reinforcing the stratum from the shield and the effect of reinforcing the stratum from the water surface to the deeper stratum are difficult to ensure, and soil bodies in the lower range of the tunnel cannot be reinforced from the water surface, so that the dependence on freezing is higher, and the freezing construction is quite critical. The freezing range and the strength are required to ensure the safety of the opening of the working well, the safety of soil excavation between the cutter head and the working well and the water stopping effect at the tail, shell and portal positions.
Specifically, the invention provides a maintenance and re-pushing construction method for a river bottom ultra-deep high water pressure shield, which can be used in shallow water and deep water, but has more advantages in deep water with the water depth exceeding 20 meters, as shown in figure 1, and comprises the following steps:
step 1: prefabrication of the open caisson is completed in a factory.
Preferably, the plane shape of the open caisson adopts a round shape. The net size in the open caisson needs to meet the space required by shield receiving, secondary starting, maintenance and freezing construction. The net size in the open caisson is determined by the following formula:
wherein: d (D) i Is the diameter of the inner wall of the open caisson;
r T the radius of the shield machine is the maximum value;
a is radial residual width which is not less than 2 m;
l T the length of the shield machine;
b is the longitudinal residual width which is not less than 3 meters.
Furthermore, the sinking well wall adopts a steel-concrete combined structure, the steel shell is arranged at the inner well wall, and the steel shell is connected with the concrete structure through cylindrical head welding nails. And reinforcing the concrete by adopting glass fiber reinforced plastic in the range of the secondary starting tunnel portal. The secondary starting tunnel portal adopts glass fiber reinforced concrete to facilitate the direct cutting of the cutter head of the follow-up shield machine, and the secondary starting tunnel portal is not needed to be broken and then pushed like reinforced concrete.
Preferably, a steel shell is arranged at the inner well wall, firstly, in order to improve the waterproof performance, because the open caisson is high in a one-to-one joint mode, construction joints exist horizontally in the concrete pouring process, the construction joints bear weak and water seepage is easy, and the inner steel plates are connected up and down in the height connecting process through welding. Secondly, the range of the secondary-originating portal adopts glass fiber reinforced concrete, the folding resistance of the secondary-originating portal is slightly weaker than that of reinforced concrete, and the bearing capacity of the well wall can be improved by internally arranging a steel shell, so that the secondary-originating portal is safer. The outside of the well wall is not required to be provided with a steel shell, firstly, the well wall is mainly subjected to axial force, the bending moment is not large, the bending moment is at the portal at the maximum, and the inside is pulled, secondly, the workload of breaking two layers of steel plates at the portal is large, and the shield machine directly cuts the portal after the original place is planned to be backfilled, and the cutter head is not used for cutting the steel plates.
Preferably, an orifice pipe for freezing construction is reserved on the well wall, so that the later freezing pipe is conveniently arranged, as shown in fig. 2. Because the freezing construction below the tunnel can only be performed by punching the freezing pipe from the working well, the freezing pipe along the circle of the tunnel is punched from the open caisson to the outside. Before the freezing pipe is drilled, an orifice pipe is needed to be buried in the well wall, and the orifice pipe is mainly used for positioning and fixing the freezing pipe. It is difficult to open holes in steel plates and concrete structures of approximately 2 meters in thickness, so that in the process of prefabricating the open caisson, the orifice pipes are pre-buried in the well wall, as shown in fig. 3.
The height of the first section open caisson is not lower than the water depth.
The first section open caisson is prefabricated, and the rest can be prefabricated or cast-in-situ on site.
The total height of the open caisson is calculated according to the following formula, so that river water can not enter the open caisson from the top, and enough construction space is provided at the bottom of the well:
H＝H W +H S +2r T +H O +H B
H W ＝H W1 +H W2
h is the total height of all well sections of the open caisson;
H W the height from the bottom of the river to the top of the open caisson;
H S the thickness of the earth is covered on the top of the shield;
H O the height of the construction space required from the shield bottom to the top of the top plate, such as guide rail construction and freezing construction, is not less than 1 meter;
H B is the thickness of the top plate;
H W1 the height of the water level is from the river bottom to the level of a flood in twenty years;
H W2 the height is not less than 2 meters in order to consider the wave climbing and the safety heightening.
The thickness of the well wall of the open caisson is determined after structural calculation is carried out according to the specification.
Step 2: and setting up a temporary construction platform on the water surface, transporting the first section open caisson to a shield stop position, sinking the first section open caisson a certain distance in front of a shield cutterhead, and implantation.
The temporary construction platform can be in the form of a trestle or a floating crane.
The clear distance between the open caisson and the cutterhead is not less than 2 meters. In order to prevent disturbance of sinking construction of the open caisson to the shield, the open caisson should be as far away from the cutterhead as possible; the further the open caisson is away from the cutter head, the longer the shield machine is pushed into the open caisson. If the distance is long, firstly, the length of freezing reinforcement is lengthened, and the freezing difficulty is increased; secondly, the risk of excavating soil body in the freezing wall and empty pushing the shield tunneling machine is increased.
Grouting reinforcement treatment can be carried out on the stratum around the shield and in front of the cutterhead before sinking, and reinforcement construction can be carried out from the inside of the shield machine or from the water surface. But not in the sinking range of the open caisson. The reinforcement is mainly used for preventing disturbance of open caisson construction to a shield, so that the shield machine is displaced. The reinforcement in the sinking range is not possible because the sinking well is not sinking when the sinking well is reinforced or the sinking deflection is possibly caused when the sinking well is partially reinforced. Grouting in the shield machine mainly depends on a grouting system of the shield machine, such as radial grouting and advanced grouting, and the common shield machine is adopted. The water surface can be reinforced by stirring piles, jet grouting piles and the like, and the stirring piles and the jet grouting piles can be adopted because the reinforcing requirement is not high and mainly auxiliary measures are adopted.
Step 3: and (5) connecting the sections to the height, sinking the sinking well until the design elevation is reached, sealing the bottom, and constructing a guide rail of the shield tunneling machine.
The plan view of the sunk well is shown in fig. 4 and 5, the sectional height of the sunk well is determined according to the depth of the sunk well, and each section is recommended to be 5-10 meters. This height is mainly considered the lifting or casting concrete height.
If other open caissons except the first open caisson are prefabricated in factories and transported to the site for height connection, a reinforcing steel bar joint is reserved on the prefabricated part, and concrete or grouting is cast after the contact surface; and if the construction is in-situ cast-in-situ construction, casting concrete on the site frame template. The inner wall steel shells are welded on site, and the inner wall steel shells can be used as templates in cast-in-situ construction.
Step 4: and (3) drilling and actively freezing the freezing pipe in the pre-buried orifice pipe along the outer ring of the shield shell and within the range of the tunnel portal on the well wall of the receiving place to form a stable freezing wall.
The freezing construction of the traditional working well only needs to ensure that the cave door is not collapsed and the cave door is not permeated with water, and the frozen soil basically does not bear load because the shield machine is used for cutting from the inside. The working condition of this patent is because the soil body in the tunnel within range needs to excavate between follow-up blade disc and the open caisson wall of a well, just the excavation distance is along vertical requirement not more than 2 meters at every turn, but in the diameter surpasses shield shell external diameter, long such space of 2 meters, freezes the wall and needs to bear outside soil and water load to support, form the passageway of secret excavation construction. The freezing wall is equivalent to a circular ring-shaped freezing wall, is somewhat similar to a segment, but has larger thickness and bears external water and soil load.
The longitudinal reinforcement length of the segment and the shield shell outer freezing wall is calculated as follows:
l＝l 1 +l T +l 2
l is the longitudinal reinforcement length of the freezing wall outside the segment and the shield shell;
l 1 in order to achieve the distance from the longitudinal well wall of the tunnel to the cutter head, the well wall is round, so that the distances between different pile numbers are different;
l 2 the length of the shield tail pipe piece wrapped by the freezing wall is not less than 5 meters.
The freezing wall must form reliable water stop between the segment behind the shield tail, the shield shell and the well wall. In particular, the shield machine is required to wrap the segments in a certain range behind the shield tail, because the shield machine is required to push forward in the freezing wall, and if the segments of the shield tail are not wrapped and only frozen to the shield tail, the segments are frozen weak links. Once the shield machine is pushed forward, the freezing wall at the shield tail is disturbed, water in the stratum flows along the gap between the duct piece and the shield shell from the shield tail, and if soil in front of the cutter head is excavated, the water at the shield tail flows to a channel in front of the cutter head and flows into the open caisson, so that freezing failure is caused. If the segment with a certain range behind the shield tail is wrapped, even if the shield machine is pushed to disturb the freezing wall, the segment and the freezing wall are still glued, a closed space is still formed among the segment, the freezing wall and the wall of the open caisson, and water and sand burst cannot occur.
And reinforcing the whole range from the tunnel portal to the cutterhead in the shield shell. The soil body in front of the cutterhead is required to be frozen and reinforced, and the stability of the soil body in front of the cutterhead in the later excavation process is mainly considered.
The freezing can be by brine method, liquid nitrogen method, dry ice method, etc.
Step 5: chiseling a receiving well wall, chiseling frozen soil to a cutter head in sections, and applying the frozen soil to a circumferential lining, wherein the chiseling length is not more than 2 meters each time. And (3) in the chiseling process, maintaining the freezing between the well wall and the cutterhead until the length of the residual frozen soil is not more than 2 meters, removing a freezing pipe in the range of the tunnel portal, chiseling the residual frozen soil, and constructing the residual lining to the cutterhead. And a slide rail is arranged in the lining. The frozen soil between the cutter head and the well wall is excavated in a sectionalized mode, because the frozen soil is chiseled, the space is subjected to external water and soil pressure by the frozen wall outside the shield shell, in order to reduce the load bearing range of the frozen wall and improve the safety, the frozen soil is excavated in a sectionalized mode along the longitudinal direction, lining is timely built inside, the frozen wall can be assisted to bear external load, disturbance of construction on the frozen wall in a channel can be isolated, the situation that the frozen wall is glued with the shield machine shell to be pushed in the air pushing process can be prevented, and an installation space is provided for a slide rail of the shield in the air pushing process. In the process, the freezing construction before the cutterhead is ensured to be continuous until the length of the rest non-excavated frozen soil is not more than 2 meters. According to the above, reinforcing measures such as stirring piles, jet grouting piles and the like can be adopted before the cutterhead, the main effects of freezing and reinforcing are the best, the quality is well controlled, the exposed soil layer in the excavation process is high to reach the diameter of the shield, and the strength of frozen soil can be guaranteed not to be damaged.
The inner diameter of the annular lining is not smaller than the diameter of the shield shell, and a steel shell or a reinforced concrete structure can be adopted. The circumferential lining should be reliably connected to the portal structure. The inner diameter of the lining cannot be smaller than the outer diameter of the shield shell, and a sliding rail is arranged in the lining to ensure that the shield can pass through the lining. The circumferential lining can be formed by welding steel shells in a blocking manner, and can also be of a cast-in-situ reinforced concrete structure. The reliable connection is formed between the annular lining and the portal of the open caisson, so that the displacement of the structure is prevented. Because the annular lining is not a main component for bearing external water and soil load, the annular lining can bear the load generated by the weight and the dead weight of the shield machine, if the thickness of the steel shell is about 2 cm, and if the thickness of the reinforced concrete is about 40 cm.
The well wall is chiseled by adopting manual or small-sized machinery, so that the damage to the freezing wall of the lining outer ring is avoided.
And fixing the freezing pipe in the tunnel portal in the process of chiseling frozen soil. When the frozen soil before the cutter head is excavated, the rest frozen soil is ensured to be in a frozen state, so that the freezing construction cannot be stopped.
Step 6: the shield machine is pushed into the lining, and tunnel segments are synchronously assembled until the shield machine completely enters the open caisson. A water stopping measure is carried out at the receiving hole, and a water stopping steel ring is arranged at the receiving hole as shown in fig. 6 and 7. Stopping freezing construction, removing the freezing equipment, and welding a steel plate at the cutting position of the orifice pipe to make sealing.
If the frozen wall bonds the shield shell and cannot be pushed in the air pushing process, the air pushing can be realized by adopting modes of controlling heating in the shield shell, cutting frozen soil adjacent to the shield shell and the like. The method mainly aims at the problems that when the shield is just pushed in the air, the frozen wall is developed during the period of actively freezing and stopping the shield to assemble the segments, the frozen wall is glued with the shield shell to fix the shield machine, and the shield machine does not exist after entering the annular lining.
The water stopping measure can adopt a conventional water stopping steel ring.
Step 7: and disassembling and maintaining the shield machine in the open caisson.
In the overhaul and repair processes, equipment and instruments can be lifted in and out from the wellhead.
Step 8: and (3) cutting off the inner steel shell at the position of the secondary initial portal in a layered manner from bottom to top, synchronously backfilling the open caisson, backfilling mortar in the range of about 2 meters close to the portal, and backfilling soil at the rest positions.
The layering height is not more than 2 meters. The layering height is not more than 2 meters, so that safety when the secondary starting tunnel portal is removed is guaranteed, and meanwhile backfilling quality can be better controlled through layering backfilling.
Backfilling to the original water bottom elevation or planning the water bottom elevation.
The backfill can be earth after the mud generated in the sinking process of the sinking well is treated.
Step 9: the repaired shield tunneling machine continues tunneling forwards along the route from the backfilled open caisson, and the shield tunneling machine leaves the open caisson after cutting mortar and glass fiber reinforced concrete well walls.
Step 10: and removing the open caisson structure in the range above the water bottom.
Blasting demolition may be employed.
The invention provides a maintenance and re-pushing construction method for a river bottom ultra-deep high water pressure shield, which can solve the problem of engineering stagnation caused by the fact that a shield machine is stopped and cannot be repaired in a hole in the river and sea deep water, has wide application range, is applicable to most underwater tunnels in China, can be used for hoisting and transporting through a wellhead by setting an underwater anhydrous working face, can greatly improve the waterproof and bearing performance of an open caisson due to the fact that various equipment faults of the shield can be hoisted and transported in the well or transported to the engineering repair by the wellhead, greatly reduces the starting risk due to secondary starting after filling, and can be popularized to the construction of the shield tunnel with the tunneling length exceeding the tunneling life of the shield machine or main parts which must be replaced in the sea and the river.
The above embodiments are provided to illustrate the technical concept and features of the present invention and are intended to enable those skilled in the art to understand the content of the present invention and implement the same, and are not intended to limit the scope of the present invention. All equivalent changes or modifications made in accordance with the spirit of the present invention should be construed to be included in the scope of the present invention.
Claims (10)
1. The maintenance and re-pushing construction method for the river bottom ultra-deep high water pressure shield is characterized by comprising the following steps of:
step 1: sectional prefabricated open caisson;
step 2: setting up a temporary construction platform on the water surface, transporting the first section open caisson to a shield stop position, sinking the first section open caisson in front of a shield cutterhead, and carrying out implantation;
step 3: the sinking well is raised and sunk in sections until the design elevation is reached, the bottom sealing is completed, and a guide rail of the shield tunneling machine is constructed;
step 4: carrying out freezing pipe drilling construction and positive freezing construction on the well wall of the receiving place along the outer ring of the shield shell and in the pre-buried orifice pipe in the range of the portal to form a stable freezing wall;
step 5: cutting off a receiving well wall, chiseling frozen soil to a cutter disc, synchronously applying a circular lining, maintaining the freezing of the residual frozen soil in front of the cutter disc in the range of a tunnel portal in the chiseling process until the length of the residual frozen soil is not more than 2 meters, dismantling a freezing pipe in the range of the tunnel portal, and arranging a sliding rail in the circular lining;
step 6: the shield machine is pushed to the annular lining, simultaneously, tunnel segments are assembled and synchronous grouting is carried out to fill gaps between the tunnel segments and the annular lining until the shield machine completely enters the open caisson, water stopping measures are taken at a receiving portal, freezing construction is stopped, freezing equipment is dismantled, and steel plates are welded at cutting positions of orifice pipes to be sealed;
step 7: disassembling and maintaining the shield machine in the open caisson;
step 8: the inner steel shell at the position of the secondary initial portal is cut off from bottom to top in a layered manner, the open caisson is backfilled synchronously, mortar is backfilled in the range of about 2 meters close to the portal, and soil is backfilled at the rest positions;
step 9: the repaired shield tunneling machine continues tunneling forward along the route from the backfilled open caisson, and leaves the open caisson after the well wall is cut;
step 10: and removing the open caisson structure in the range above the water bottom.
2. The method for maintaining and re-pushing the ultra-deep high water pressure shield at the bottom of a river according to claim 1, which is characterized in that:
the planar shape of the open caisson is circular, and the net size in the open caisson is as follows to meet the space requirements for shield receiving, secondary starting, maintenance and freezing construction:
wherein: d (D) i Is the diameter of the inner wall of the open caisson; r is (r) T The radius of the shield machine is the maximum value; a is radial residual width which is not less than 2 m; l (L) T The length of the shield machine; b is the longitudinal residual width which is not less than 3 meters.
3. The method for maintaining and re-pushing the ultra-deep high water pressure shield at the bottom of a river according to claim 1, which is characterized in that,
the open caisson is manufactured in sections, the height of the first section open caisson is not lower than the water depth, the total height of the open caisson is calculated according to the following formula to ensure that river water cannot enter the open caisson from the top, and enough construction space is provided at the bottom of a well:
H＝H W +H S +2r T +H O +H B
wherein H is the total height of all well sections of the open caisson; h S The thickness of the earth is covered on the top of the shield; h O The height of the construction space required from the shield bottom to the top of the bottom plate of the open caisson is not less than 1 meter; h B Is the thickness of the bottom plate; h W The height from the river bottom to the top of the open caisson is as follows:
H W ＝H W1 +H W2
wherein H is W1 The height of the water level is from the river bottom to the level of a flood in twenty years; h W2 The height is not less than 2 meters in order to consider the wave climbing and the safety heightening.
4. The method for maintaining and re-pushing the ultra-deep high water pressure shield at the bottom of a river according to claim 3, which is characterized in that:
step 2, the open caisson wall adopts a combined structure of steel and concrete, the main body is of a concrete structure, a steel shell is arranged at the inner wall, the steel shell is connected with the main body through cylindrical head welding nails, the steel shell is arranged at the inner wall, so that the waterproof performance is improved, the bearing capacity of the wall is improved, the safety is improved, and meanwhile, the steel shell is not arranged on the outer wall so as to reduce the workload of subsequent opening and removal.
5. The method for maintaining and re-pushing the ultra-deep high water pressure shield at the bottom of a river according to claim 1, which is characterized in that,
in the step 4, the longitudinal reinforcement length of the segment and the outer frozen wall of the shield shell is calculated according to the following formula so as to meet the soil excavation requirement in the tunnel range between the follow-up cutter head and the well wall of the open caisson, and under the special working condition of excavating frozen soil, the frozen wall is required to bear external water and soil load so as to support and form a channel for underground excavation construction, so that the special scene of sealing water of the tunnel, the shield machine and the open caisson is ensured:
l＝l 1 +l T +l 2
wherein l is the longitudinal reinforcement length of the freezing wall outside the segment and the shield shell; l (L) 1 In order to achieve the distance from the longitudinal well wall of the tunnel to the cutter head, the well wall is round, so that the distances between different pile numbers are different; l (L) 2 The length of the shield tail pipe piece wrapped by the freezing wall is not less than 5 meters.
6. The method for maintaining and re-pushing the ultra-deep high water pressure shield at the bottom of a river according to claim 1, which is characterized in that,
and 4, wrapping the segment behind the shield tail by the frozen wall, and ensuring that the segment and the frozen wall still keep a cementing state under the condition that the frozen wall is disturbed by pushing of the shield machine, so that the water and sand gushing condition can not occur.
7. The method for maintaining and re-pushing the ultra-deep high water pressure shield at the bottom of a river according to claim 6, which is characterized in that,
step 5 chiseling frozen soil from the cutter head is carried out in a longitudinal section, the section length is not more than 2 meters so as to control the bearing range of the frozen wall and further reduce the excavation risk, and annular lining is timely applied inside the cutter head to assist the frozen wall to bear external load, so that disturbance of construction on the frozen wall in a channel is isolated, the situation that the frozen wall is glued with the shell of the shield machine in the air pushing process and is not moved is prevented, and an installation space is provided for a sliding rail of a shield to be pushed in the air at the rear.
8. The method for maintaining and re-pushing the ultra-deep high water pressure shield at the bottom of a river according to claim 7, wherein,
and 8, the layering height is not more than 2 meters, so that the safety when the secondary starting tunnel portal is removed is ensured, and meanwhile, the layering backfilling can better control the backfilling quality.
9. The method for maintaining and re-pushing the ultra-deep high water pressure shield at the bottom of a river according to claim 8, which is characterized in that,
and 2, the clear distance between the open caisson and the cutterhead is not less than 2 meters, soil between the open caisson and the cutterhead is reinforced before sinking, and disturbance of sinking construction of the open caisson to a shield machine and a tunnel is avoided.
10. The method for maintaining and re-pushing the ultra-deep high water pressure shield at the bottom of a river according to claim 9, which is characterized in that,
and 5, the thickness of the circumferential lining is 1.5-2.5 cm when the steel material is adopted, and the thickness of the circumferential lining is 35-45 cm when the concrete material is adopted, so that the load generated by the weight and the dead weight of the shield machine is borne.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310647761.5A CN116856949A (en) | 2023-06-02 | 2023-06-02 | Maintenance and re-pushing construction method for river bottom ultra-deep high water pressure shield |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310647761.5A CN116856949A (en) | 2023-06-02 | 2023-06-02 | Maintenance and re-pushing construction method for river bottom ultra-deep high water pressure shield |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116856949A true CN116856949A (en) | 2023-10-10 |
Family
ID=88233022
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310647761.5A Pending CN116856949A (en) | 2023-06-02 | 2023-06-02 | Maintenance and re-pushing construction method for river bottom ultra-deep high water pressure shield |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116856949A (en) |
-
2023
- 2023-06-02 CN CN202310647761.5A patent/CN116856949A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109723065B (en) | Reinforcing device and deep foundation pit local freezing reinforcing construction method in water-rich gravel stratum | |
| CN108691550B (en) | Vertical shaft shield machine for underground upward construction and construction method thereof | |
| CN109322671B (en) | Method for getting rid of worn and trapped shield cutter | |
| CN105863648B (en) | A kind of tunneling is shallow to cover large-section tunnel construction method | |
| CN106812540B (en) | Shield initial plain wall sealing water-stopping reinforcing structure and construction process | |
| CN110984236B (en) | Construction method for connecting point of sleeved type light and shade excavation structural portal interface | |
| CN109578014B (en) | Anti-surging bottom sealing structure and construction method | |
| CN111101540B (en) | Construction method for passing existing electric power tunnel on open cut tunnel | |
| CN111236387B (en) | Construction method for connecting newly-built sewage pipe with existing sewage pipe | |
| JP2010126996A (en) | Method for preventing lining body from floating up | |
| CN112664221A (en) | Pipe jacking construction method for complex geological formation | |
| CN112727466A (en) | Construction method for support-free prefabricated assembled type shield tunnel air shaft structure | |
| CN110905536A (en) | Construction method for receiving complex stratum earth pressure shield in underground excavation tunnel | |
| CN206888992U (en) | A kind of water-bed mine shield tunnel combination docking structure form | |
| CN113669073B (en) | Construction method for controlling adjacent building deformation of water-rich sandy stratum by tunneling before station | |
| CN108755719A (en) | Seabed municipal tunnel over strait cofferdam open cutting construction method | |
| CN110512649B (en) | Underground excavation construction method for additionally arranging basement and communication channel structure under existing building | |
| CN116398165A (en) | New tunnel penetrating through existing station at zero distance and construction method thereof | |
| CN110566217A (en) | shallow-earth-covered shield construction method | |
| CN116856949A (en) | Maintenance and re-pushing construction method for river bottom ultra-deep high water pressure shield | |
| CN114754194A (en) | Storage tank top pipe installation device and construction method thereof | |
| CN209430204U (en) | Anti- dash forward of one kind gushes back cover structure | |
| CN114542092A (en) | Shield receiving construction method without bottom plate structure | |
| CN115929319A (en) | Underwater butt joint structure of shield tunnel and construction method thereof | |
| CN211648163U (en) | Self-propelled open type shield machine system for constructing underground box culvert |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |