CN111305225A

CN111305225A - Engineering construction method of underground protective structure

Info

Publication number: CN111305225A
Application number: CN202010158220.2A
Authority: CN
Inventors: 李宏涛; 王江延; 李世清; 张义冬
Original assignee: China Railway Science Construction Engineering Co ltd
Current assignee: China Railway Science Construction Engineering Co ltd
Priority date: 2020-03-09
Filing date: 2020-03-09
Publication date: 2020-06-19
Anticipated expiration: 2040-03-09
Also published as: CN111305225B

Abstract

The invention discloses an engineering construction method of an underground protective structure, which comprises the following steps: s1, constructing a continuous wall on a construction site, wherein the continuous wall comprises a first continuous wall and a second continuous wall which are arranged at intervals; s2, forming at least two steel open caisson arranged at intervals at the designated position between the two continuous walls, excavating soil in the steel open caisson and between the steel open caisson, sinking the steel open caisson to the designed depth, forming a first space by the excavated part between the steel open caisson, and forming a second space by the excavated part in the steel open caisson; s3, constructing a first main body structure in a first space between the steel open caisson; s4, dismantling the steel open caisson and carrying out second main body structure construction in a second space; and S5, repeating the steps until all the main body structures are constructed. The underground protection structure built by the method has good integrity. Need not to enclose extra construction input such as purlin, lattice column, the construction space who forms is big, is particularly useful for slender type foundation ditch to support, like subway, underpass tunnel, piping lane etc..

Description

Engineering construction method of underground protective structure

Technical Field

The invention relates to the technical field of underground protective structures, in particular to an engineering construction method of an underground protective structure.

Background

At present, multi-purpose concrete beams or steel pipes of slender foundation pits excavated by constructing subway stations, underpass tunnels, culverts and the like are used as transverse supports, lattice columns are used as longitudinal supports, rows of supporting structures such as stirring piles and drilled piles are used on the side walls of the foundation pits, and internal supports are required to be removed after the construction of underground structures is finished. The construction steps are as follows: pouring piles, constructing rotary spraying piles → constructing lattice columns → lowering water in pits → excavating soil to constructing a crown beam and a first support → excavating soil to a second support at the designed height, constructing surrounding purlins and a second support → repeating the steps until all the supporting construction is finished → a cushion layer and foundation construction → the first section of the main structure (the bottommost section) → removing the bottommost section of the support (including transverse supports, surrounding purlins and longitudinal lattice columns, the same below) → second section of the main structure construction → removing the second support → repeating the steps until the whole construction of the main structure is finished → backfilling a top plate.

The construction method has the following defects: 1. the construction quantity of the cast-in-place piles and the jet grouting piles is large, the construction speed is low, each pile is independently constructed, and a large amount of manpower and material resources are required to be input to ensure the construction progress; 2. the cast-in-place pile and the jet grouting pile are separately constructed and are mutually meshed only by concrete, so that the construction requirement is high, the integrity is poor, the water interception and seepage resistance is poor, and the construction risk is higher particularly in the area with confined water; 3. reinforcing steel bars in the cast-in-place pile are distributed annularly, and part of the reinforcing steel bars are basically not stressed and cannot fully play a role; 4. the transverse support is in a rod piece form, so that the requirement on overall stability is met, a large number of pieces of transverse support are densely arranged, the construction is slow, the turnover efficiency is low, the cost is high, a plurality of monitoring points are provided, and the management difficulty is high; 5. a plurality of surrounding purlins are required to be arranged, and the purlins are required to be dismantled in the construction process, so that the structure is a disposable temporary structure, the workload is large, the manufacturing cost is high, and the materials and the energy are not saved; 6. a plurality of longitudinal lattice column supports are required to be arranged, and the lattice column supports are required to be dismantled in the construction process, so that the lattice column supports are of a disposable temporary structure, and are large in workload, high in manufacturing cost, material-saving and energy-saving; 7. the transverse support is dense, the use of mechanical equipment is limited, and the unearthing is difficult; 8. the longitudinal support is dense, the construction space is small, and the construction efficiency is seriously influenced. If the support is displaced or damaged due to careless operation of the construction machinery in the foundation pit, more serious safety accidents can be caused; 9. the main structure is constructed in a subsection mode from bottom to top, a horizontal construction joint is generated on the side wall of the structure, the structural integrity is weakened, and the waterproof and anti-permeability capability is reduced; 10. the larger the depth of the foundation pit is, the more times the input amount of the transverse support is increased; 11. the wider foundation pit is limited in supporting capacity, the wider the foundation pit is, the longer the transverse supporting rod is, instability is easy to occur, and more lattice columns need to be added to ensure stability.

Disclosure of Invention

Aiming at the problems, the invention aims to provide a construction method of an underground protection structure, which has the advantages of short construction period, high construction efficiency, good integrity, controllable quality, low manufacturing cost and low management difficulty.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

an engineering construction method of an underground protective structure comprises the following steps:

and S1, constructing the continuous wall on a construction site, wherein the continuous wall comprises a first continuous wall and a second continuous wall which are arranged at intervals, and the first continuous wall and the second continuous wall are respectively driven into the foundation to a specified depth.

S2, manufacturing and forming at least two steel open caisson arranged at intervals at the designated position between the two continuous walls, wherein two sides of each steel open caisson are respectively contacted with the first continuous wall and the second continuous wall, excavating soil in the steel open caisson and between the steel open caisson, so that the steel open caisson sinks to the designed depth, the excavated part between the steel open caisson forms a first space, and the excavated part in the steel open caisson forms a second space.

And S3, constructing a first main body structure in the first space between the steel open caisson.

And S4, dismantling the steel open caisson and carrying out second main structure construction in the second space.

And S5, repeating the steps S2-S4 until all the main body structures are constructed.

Further, in step S2, a plurality of blade foot blocks and a plurality of standard blocks manufactured in a factory are transported to a construction site, a plurality of blade foot layers are formed at designated positions between two continuous walls by splicing the plurality of blade foot blocks, and a space formed inside each blade foot layer and a space region formed between adjacent blade foot layers are excavated to sink the blade foot layers to a designated height; and forming one to many standard layers on the upper part of each blade foot layer through splicing of a plurality of standard blocks, and continuously excavating soil until the steel open caisson sinks to the designed depth.

The blade foot layer is connected with the standard layer, the standard layer is connected with the standard layer, the blade foot blocks are connected with the blade foot blocks, and the standard blocks are connected with the blade foot blocks in one or more combinations of welding, riveting, bolting, gluing and socket joints.

The edge foot block comprises a shell with a closed bottom and an open top and a plurality of internal supporting pieces fixedly arranged inside the shell, the standard block comprises an inner layer plate, an outer layer plate and a plurality of internal supporting pieces fixedly arranged between the inner layer plate and the outer layer plate, and filling cavities are respectively arranged inside the edge foot block and the standard block.

Further, if the steel open caisson cannot sink, filling material balance weights are uniformly placed in the filling cavity, so that the steel open caisson sinks.

Further, if the steel open caisson sinks or inclines unevenly, filling materials are placed in the corresponding filling cavities to perform dynamic deviation correction.

Preferably, the filling material is one or more of concrete, sand, soil, stone, brick, water, slurry, foamed foam and foamed concrete.

Furthermore, the continuous wall is of a reinforced concrete connection and concrete integrated pouring structure.

The invention has the following beneficial effects:

1. the side wall enclosure structure adopts the underground continuous wall, is hardly limited by geological conditions, has stable technology, mature process and high mechanization degree, saves structures such as a crown beam, an enclosing purlin and the like, saves construction and dismantling costs of corresponding structures and occupied construction period, is environment-friendly, saves materials and has high efficiency.

2. And the reinforcing steel bars in the underground continuous wall are all positioned in the compression area, so that the working performance of the reinforcing steel bars can be fully exerted. The wall body has high rigidity and can bear larger soil pressure, and the supporting structure can support soil retaining and water stopping; compared with the row pile, the construction period can be shortened, the cost is indirectly reduced, and meanwhile, the influence on surrounding buildings and underground facilities is small.

3. The underground continuous wall is transversely connected with concrete by adopting steel bars and integrally poured, has good integrity and controllable quality, and can intercept water and resist seepage;

4. the underground continuous wall can be in parallel lap joint construction with the open caisson, and the construction period is greatly shortened.

5. Compared with a rod piece, the open caisson structure has the advantages of good structural integrity, high rigidity, high bearing capacity and low possibility of instability, and meanwhile, the support structure cannot be damaged and destabilized due to operation affairs of large machinery.

6. The formed operation space is large, the expansion operation of construction equipment is facilitated, other supporting structures do not interfere with the construction in the longitudinal space, and the construction efficiency can be obviously improved.

7. Utilize the open caisson to cut apart into a plurality of independent blocking's little foundation ditch with the foundation ditch, factor of safety is higher, can expand a plurality of operation face constructions simultaneously, and every operation space construction does not influence each other. The method can adopt the methods of subsection, partition, layered construction and the like, and the construction organization is flexible.

8. The main structure in the foundation pit can be constructed in one step in the vertical direction, and the side wall of the main structure cannot have a horizontal construction joint, so that the structural integrity and the waterproof and anti-permeability capability are ensured.

9. Compared with sectional construction, the same main body structure obviously shortens the construction period.

10. The working surfaces of various types are independent, the mutual interference is small, and the management and scheduling difficulty is small.

11. The open caisson can be used for geological conditions by adopting a method of going out while sinking, and can also be used for going out in place in one-time sinking and the like, so that the open caisson has high applicability.

12. The open caisson is assembled and formed by adopting a steel structure, and is flexible to deploy. After the construction of the corresponding section is completed, the construction can be deployed to the next section, the construction of all main body structures is not required to be completed, and the turnover efficiency is high.

13. The open caisson sealing bottom can be used as a main structure foundation or a cushion layer, so that the construction cost is reduced, and the construction period is shortened.

Drawings

FIG. 1 is a schematic view of a construction process 1-the first part of underground diaphragm wall construction.

Fig. 2 is a schematic view of the construction process 2-open caisson assembling in place.

FIG. 3 is a schematic view of the construction process 3-the excavation and sinking are carried out until the designed bottom elevation is reached.

FIG. 4 is a schematic diagram of a construction process 4, namely the construction of a main structure part and the next part of underground continuous wall between open caisson.

FIG. 5 is a schematic diagram of a construction process 5, in which the main structure of the position of the original open caisson is partially constructed and the open caisson is circulated to the next construction section for excavation and sinking.

FIG. 6 is a schematic diagram of a construction process 6, namely the construction of the main structure part and the next part of the underground continuous wall of the next section of the open caisson.

FIG. 7 is a schematic diagram of a construction process 7, in which a main structure part of the position of the next section of the original open caisson is constructed and the open caisson is circulated to the next construction section for excavation and sinking.

Fig. 8 is a construction flowchart.

Fig. 9 is a schematic plan view of the present invention.

Fig. 10 is a schematic cross-sectional view of the present invention.

Fig. 11 is a perspective view of the edge block.

Fig. 12 is a schematic perspective view of a standard block with closed side edges.

Fig. 13 is a schematic perspective view of a standard block with non-enclosed side edges.

Fig. 14 is a schematic structural view (form one) of the blade foot.

Fig. 15 is a schematic structural view of the blade leg (form two).

Fig. 16 is a schematic structural view (form three) of the blade leg.

Fig. 17 is a schematic view of the structure of the blade foot (form four).

Fig. 18 is a schematic structural diagram of a standard block.

Description of the main component symbols: 1. a continuous wall; 2. a steel open caisson; 201. a blade foot block; 202. a standard block; 203. filling the cavity; 204. a housing; 205. an inner support; 206. an inner layer board; 207. an outer plate; 21. a blade foot layer; 22. a standard layer; 31. the area between the steel open caisson 2; 32. the area inside the steel open caisson 2; 4. a foundation; 51. a first body structure portion; 52. a second body structure portion.

Detailed Description

The invention is further described with reference to the following drawings and detailed description.

As shown in fig. 1 to 18, a method for engineering construction of an underground protective structure includes the following steps:

the method comprises the following steps: and designing the steel open caisson 2 according to the project geological survey report and the project specific situation. The corner block 201 and the standard block 202 are all manufactured in a factory. The blade foot block 201 has a three-dimensional structure as shown in fig. 11, the blade foot block 201 includes a housing 204 with a closed bottom and an open top, and a plurality of internal supporting members 205 fixed inside the housing 204, and the bottom surface of the blade foot block 201 may be in the form of a single bevel, a double bevel, or the like, as shown in fig. 14-17. The modular block 202 has a three-dimensional structure and a planar structure as shown in fig. 12, 13 and 18, respectively, and the modular block 202 includes an inner plate 206, an outer plate 207 and a plurality of internal supporting members 205 fixed between the inner plate 206 and the outer plate 207. The inside of the edge block 201 and the standard block 202 are respectively provided with a filling cavity 203. The steel open caisson 2 can be divided into two groups, 3 groups and up to a plurality of groups, and is designed according to the requirement of field turnover. For convenience of explanation, this patent takes 4 pieces as an example.

Step two: meanwhile, the construction site performs the construction of the first underground diaphragm wall 1. The continuous wall 1 is a reinforced bar connection concrete integrated pouring structure (the construction technology of the underground continuous wall 1 is mature and common, and the specific construction method is not described in detail herein); and after the construction of the first part of underground continuous wall 1 is finished, the construction of the underground continuous wall 1 of the next construction section is carried out.

Step three: the transportation blade corner block 201 and the standard block 202 are transported to a construction site.

Step four: according to the design, a connecting blade corner block 201 is assembled at a designated position between two underground continuous walls 1 to form a blade corner layer 21.

Step five: carry out regional 31 between steel open caisson 2, regional 32 in the steel open caisson 2 and excavate soil, make 2 sword horned layer 21 of steel open caisson sink, if steel open caisson 2 can't sink according to the design, then:

(1) if the steel open caisson 2 sinks or inclines unevenly, filling materials are placed in the corresponding filling bins 203 for dynamic deviation correction;

(2) and if the steel open caisson 2 cannot sink, uniformly placing filling material balance weights in the filling cavity 203 to enable the steel open caisson 2 to sink.

The filler is one or more of concrete, sand, soil, stone, brick, water, slurry, foam and foamed concrete.

Step six: and assembling and connecting the standard layer 22 on the upper part of the corner layer 21. The connection mode between the blade foot layer 21 and the standard layer 22, between the standard layer 22 and the standard layer 22, between the blade foot block 201 and the blade foot block 201, and between the standard block 202 and the standard block 202 is one or more of welding, riveting, bolting, gluing and socket joint.

Step seven: and (5) continuously excavating soil in the area 31 between the steel open caisson 2 and the area 32 in the steel open caisson 2, and if the steel open caisson 2 cannot be sunk according to the design at this time, processing according to the points (1) and (2) in the step 5.

Step eight: and repeating the sixth step and the seventh step until the steel open caisson 2 sinks to the designed depth.

Step nine: the first body structure part 51 is constructed in the area 31 between the steel open caisson 2.

Step ten: and (4) dismantling the middle two steel open caisson 2, transferring to the next construction section, and executing the third step to the ninth step.

Step eleven: the second main body structure part 52 is constructed at a position where two steel open caisson 2 is removed.

Step twelve: and (4) dismantling the two steel open caisson 2 at the outer side, transferring to the next construction section, and executing the third step to the ninth step.

Step thirteen: and constructing the second main structure part 52 at the position of the original open caisson at the position of the two removed outer steel open caissons 2.

Fourteen steps: and repeating the third step to the thirteenth step until all the main body structures are constructed.

While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. The engineering construction method of the underground protective structure is characterized by comprising the following steps:

s1, constructing continuous walls on a construction site, wherein the continuous walls comprise first continuous walls and second continuous walls which are arranged at intervals, and the first continuous walls and the second continuous walls are respectively driven into the foundation to a specified depth;

s2, manufacturing and forming at least two steel open caisson arranged at intervals at the designated position between the two continuous walls, wherein two sides of each steel open caisson are respectively contacted with the first continuous wall and the second continuous wall, excavating soil in the steel open caisson and between the steel open caisson, so that the steel open caisson sinks to the designed depth, the excavated part between the steel open caisson forms a first space, and the excavated part in the steel open caisson forms a second space;

s3, constructing a first main body structure in a first space between the steel open caisson;

s4, dismantling the steel open caisson and carrying out second main body structure construction in a second space;

2. The method of constructing an underground protective structure according to claim 1, wherein the step S2 comprises the steps of transporting the plurality of blade foot blocks and the plurality of standard blocks, which are manufactured in a factory, to a construction site, forming a plurality of blade foot layers at predetermined positions between the two continuous walls by splicing the plurality of blade foot blocks, excavating soil in spaces formed inside the blade foot layers and in space regions formed between adjacent blade foot layers to sink the blade foot layers to a predetermined height, forming one to many standard layers at the upper portion of each blade foot layer by splicing the plurality of standard blocks, and continuously excavating the soil until the steel caisson sinks to a designed depth.

3. The engineering construction method of an underground protective structure according to claim 2, characterized in that: the connection mode between the blade foot layer and the standard layer, between the standard layer and the standard layer, between the blade foot block and the blade foot block, and between the standard block and the standard block is one or more of welding, riveting, bolting, gluing and socket joints.

4. The engineering construction method of an underground protective structure according to claim 2, characterized in that: the edge foot block comprises a shell with a closed bottom and an open top and a plurality of internal supporting pieces fixedly arranged inside the shell, the standard block comprises an inner layer plate, an outer layer plate and a plurality of internal supporting pieces fixedly arranged between the inner layer plate and the outer layer plate, and filling cavities are respectively arranged inside the edge foot block and the standard block.

5. An engineering construction method of an underground protective structure as claimed in claim 4, characterized in that: if the steel open caisson can not sink, filling material balance weights are uniformly placed in the filling cavity, so that the steel open caisson sinks.

6. An engineering construction method of an underground protective structure as claimed in claim 4, characterized in that: if the steel open caisson sinks or inclines unevenly, filling materials are placed in the corresponding filling cavities for dynamic deviation correction.

7. An engineering construction method of an underground protective structure as claimed in claim 5 or 6, characterized in that: the filling material is one or more of concrete, sand, soil, stone, bricks, water, slurry, foaming foam and foaming concrete.

8. The engineering construction method of an underground protective structure according to claim 1, characterized in that: the continuous wall is of a reinforced concrete connection and integral pouring structure.