阅读说明：本技术 一种双排钢管桩围堰施工方法 (Double-row steel pipe pile cofferdam construction method ) 是由 李金成 李伟 何岩 刘阳阳 田加奇 龙祖蕴 杨凯旋 高帅 胡鑫 欧阳军胜 于 2019-08-06 设计创作，主要内容包括：本发明提供了一种双排钢管桩围堰施工方法,通过填土后在湖中打设双排钢管,然后将同排钢管联在一起,中间用土工布以及土工格栅将土体包裹,使其形成一个整体,用以全方位抵抗湖水进入,待围堰内部抽水完毕,在围堰内部修筑临时施工便道,由湖中水上施工变陆地施工。如此一来,不仅能保证施工的封闭性,还能避免泥浆、设备油污等对湖水环境造成污染。值得一提的是,通过对围堰的分仓施工,不仅能加快工程施工进度,极大地降低施工成本,还能提高施工安全系数。(The invention provides a construction method of a double-row steel pipe pile cofferdam, which comprises the steps of digging double-row steel pipes in a lake after filling soil, then connecting the same row of steel pipes together, wrapping a soil body by geotechnical cloth and a geogrid in the middle to form a whole body for resisting lake water from entering in all directions, building a temporary construction access way in the cofferdam after water pumping in the cofferdam is finished, and changing water construction in the lake into land construction. Therefore, the construction sealing performance can be ensured, and pollution of mud, equipment oil stain and the like to the lake water environment can be avoided. It is worth mentioning that the construction progress of the project can be accelerated through the warehouse-dividing construction of the cofferdam, the construction cost is greatly reduced, and the construction safety factor can be improved.)

1. A construction method of a double-row steel pipe pile cofferdam is characterized by comprising the following steps:

S1: primarily filling soil, namely transporting the clay to the position of the double rows of steel pipe piles, and adopting a boat to dig for filling;

S2: the concrete positions of the inner row of piles and the outer row of piles are determined, and the steel pipe piles are driven into the water bottom through a pile driver;

S3: through the piling of the step S2, longitudinally and transversely connecting the steel pipe piles which are already piled, and forming an integral cofferdam framework;

S4: after the cofferdam framework is formed, laying steel-plastic grids and geotextiles close to the inner side sheet pile and the outer side sheet pile;

S5: performing secondary filling, wherein the weir body filling and the inner and outer side soil covering are performed synchronously in the filling process, and the elevation is kept consistent;

S6: pumping water in the cofferdam, simultaneously enhancing the observation of the cofferdam and checking whether each connecting piece has a problem;

s7: after the cofferdam pumping is finished, constructing the inner side protecting slope;

S8: filling the weir body after the inner slope protection of the weir is finished, and heightening the weir body;

s9: and after the bridge construction is finished, removing residues in the cofferdam, irrigating water in the cofferdam and dismantling the cofferdam.

2. The double row steel pipe pile cofferdam construction method of claim 1, wherein the step S2 further comprises the steps of:

A1: firstly, pulling out concrete positions of an inner row of piles and an outer row of piles by using iron wires on original positioning piles of the cofferdam, and setting pile positions according to a designed interval;

a2: and B, piling by adopting an on-board excavator through the step A1, determining the depth of the pile driven into the soil layer according to design calculation, controlling the height of the pile top according to the highest water level 0.8m higher than the flood season, and driving the steel pipe pile to control the verticality.

3. The double row steel pipe pile cofferdam construction method of claim 1, wherein the step S3 further comprises the steps of:

b1, adopting phi 48 steel pipes in the longitudinal direction, respectively fixing the steel pipes on two rows of steel pipe piles, controlling the elevation to be about 1m above water, adopting diagonal steel bars in the transverse direction, respectively connecting the two rows of corresponding steel pipe piles and the transverse steel pipes into a whole, and enabling each steel pile to be transversely connected;

b2: and B1, arranging transverse bridge counter-pulling steel bars at the bottom of the double-row steel pipe pile cofferdam, and reducing the cantilever length of the steel pipes.

4. the double row steel pipe pile cofferdam construction method of claim 1, wherein the step S5 further comprises the steps of:

c1: firstly, filling the center soil of the weir to ensure that the center soil of the weir is higher than the highest water level by 0.5 m;

c2: after the step C1 is set, the weir body filling and the inside and outside soil covering are carried out synchronously in the soil filling process, the elevation is kept consistent, and the inside and outside soil filling is carried out according to the following steps of: and (5) slope placing and filling at a 2-gradient.

5. the double row steel pipe pile cofferdam construction method of claim 1, wherein the step S7 further comprises the steps of:

D1: after the water pumping of the cofferdam is finished, firstly, the engineering of filling the access and drilling platform is carried out;

d2: and D1, taking the filling sidewalk and the drilling platform as construction channels, performing elevation construction on the inner side slope protection and constructing drainage ditches, wherein the slope protection is constructed according to the gradient of 1:2, and the height of the top of the slope is about 1m from the elevation of the cofferdam top.

6. The double row steel pipe pile cofferdam construction method of claim 1, wherein the step S9 further comprises the steps of:

E1: firstly, completely removing the connection in the cofferdam;

E2: e1, after the connection and the dismantling in the cofferdam are finished, pulling out the steel pipe pile by using a vibration hammer of the pile driving barge, pulling out the steel pipe pile from the river channel by using a winch, and hoisting the steel pipe pile by using a digging machine to transfer the steel pipe pile to the ground;

e3: and E2, after the steel pipe pile is removed, removing all soil and sundries in the river channel by using a dredger, and completely removing all cofferdam substances except the design line.

Technical Field

the invention relates to the field of bridge construction, in particular to a construction method of a double-row steel pipe pile cofferdam.

Background

the method for building the steel trestle and the pile position construction platform in the bridge construction has long construction period and high construction cost, and the construction vehicle has part of construction waste left in the lake in the transportation process on the trestle, especially the construction of the bridge deck system and the hanging basket of the main bridge in the later period, and the construction waste left in the lake inevitably exists, such as: drilling mud, oil stains for daily maintenance of construction vehicles, concrete scattered in the concrete pouring process, mortar thrown in advance in the construction of main bridge hanging baskets and the like. With the increasing requirements of people on water quality, fishery cultivation, environmental protection and navigation, the construction of the double-row steel pipe pile cofferdam can fundamentally solve the defects and accords with the concepts of environmental protection, energy conservation and consumption reduction.

disclosure of Invention

in order to solve the problems, the invention provides a construction method of a double-row steel pipe pile cofferdam.

In order to realize the technical purpose, the technical scheme of the invention is as follows: a construction method of a double-row steel pipe pile cofferdam is characterized by comprising the following steps:

S1: primarily filling soil, namely transporting the clay to the position of the double rows of steel pipe piles, and adopting a boat to dig for filling;

s2: the concrete positions of the inner row of piles and the outer row of piles are determined, and the steel pipe piles are driven into the water bottom through a pile driver;

S3: through the piling of the step S2, longitudinally and transversely connecting the steel pipe piles which are already piled, and forming an integral cofferdam framework;

s4: after the cofferdam framework is formed, laying steel-plastic grids and geotextiles close to the inner side sheet pile and the outer side sheet pile;

S5: performing secondary filling, wherein the weir body filling and the inner and outer side soil covering are performed synchronously in the filling process, and the elevation is kept consistent;

s6: pumping water in the cofferdam, simultaneously enhancing the observation of the cofferdam and checking whether each connecting piece has a problem;

S7: after the cofferdam pumping is finished, constructing the inner side protecting slope;

S8: filling the weir body after the inner slope protection of the weir is finished, and heightening the weir body;

s9: and after the bridge construction is finished, removing residues in the cofferdam, irrigating water in the cofferdam and dismantling the cofferdam.

the invention has the advantages that double rows of steel pipes are arranged in the lake after filling soil, then the steel pipes in the same row are connected together, the soil body is wrapped by the geotextile and the geogrid in the middle to form a whole body for resisting lake water from entering in all directions, after the water pumping in the cofferdam is finished, a temporary construction access way is built in the cofferdam, and the construction on the lake water is changed into land construction. Therefore, the construction sealing performance can be ensured, and pollution of mud, equipment oil stain and the like to the lake water environment can be avoided. It is worth mentioning that the construction progress of the project can be accelerated through the warehouse-dividing construction of the cofferdam, the construction cost is greatly reduced, and the construction safety factor can be improved.

In a preferred embodiment of the present invention, on the basis of the foregoing, the step S2 further includes the following steps:

A1: firstly, pulling out concrete positions of an inner row of piles and an outer row of piles by using iron wires on original positioning piles of the cofferdam, and setting pile positions according to a designed interval;

a2: and B, piling by adopting an on-board excavator through the step A1, determining the depth of the pile driven into the soil layer according to design calculation, controlling the height of the pile top according to the highest water level 0.8m higher than the flood season, and driving the steel pipe pile to control the verticality.

Further, the step S3 further includes the following steps:

B1, adopting phi 48 steel pipes in the longitudinal direction, respectively fixing the steel pipes on two rows of steel pipe piles, controlling the elevation to be about 1m above water, adopting diagonal steel bars in the transverse direction, respectively connecting the two rows of corresponding steel pipe piles and the transverse steel pipes into a whole, and enabling each steel pile to be transversely connected;

b2: and B1, arranging transverse bridge counter-pulling steel bars at the bottom of the double-row steel pipe pile cofferdam, and reducing the cantilever length of the steel pipes.

Further, the step S5 further includes the following steps:

c1: firstly, filling the center soil of the weir to ensure that the center soil of the weir is higher than the highest water level by 0.5 m;

c2: after the step C1 is set, the weir body filling and the inside and outside soil covering are carried out synchronously in the soil filling process, the elevation is kept consistent, and the inside and outside soil filling is carried out according to the following steps of: and (5) slope placing and filling at a 2-gradient.

further, the step S7 further includes the following steps:

d1: after the water pumping of the cofferdam is finished, firstly, the engineering of filling the access and drilling platform is carried out;

d2: and D1, taking the filling sidewalk and the drilling platform as construction channels, performing elevation construction on the inner side slope protection and constructing drainage ditches, wherein the slope protection is constructed according to the gradient of 1:2, and the height of the top of the slope is about 1m from the elevation of the cofferdam top.

Further, the step S9 further includes the following steps:

e1: firstly, completely removing the connection in the cofferdam;

e2: e1, after the connection and the dismantling in the cofferdam are finished, pulling out the steel pipe pile by using a vibration hammer of the pile driving barge, pulling out the steel pipe pile from the river channel by using a winch, and hoisting the steel pipe pile by using a digging machine to transfer the steel pipe pile to the ground;

e3: and E2, after the steel pipe pile is removed, removing all soil and sundries in the river channel by using a dredger, and completely removing all cofferdam substances except the design line.

Drawings

FIG. 1 is a process flow diagram of the construction method of the double-row steel pipe pile cofferdam of the invention.

Detailed Description

The technical solution of the present invention will be clearly and completely described below.

In order to solve the problems, the invention provides a construction method of a double-row steel pipe pile cofferdam.

In order to realize the technical purpose, the technical scheme of the invention is as follows: a construction method of a double-row steel pipe pile cofferdam is characterized by comprising the following steps:

s1: primarily filling soil, namely transporting the clay to the position of the double rows of steel pipe piles, and adopting a boat to dig for filling;

s2: the concrete positions of the inner row of piles and the outer row of piles are determined, and the steel pipe piles are driven into the water bottom through a pile driver;

s3: through the piling of the step S2, longitudinally and transversely connecting the steel pipe piles which are already piled, and forming an integral cofferdam framework;

S4: after the cofferdam framework is formed, laying steel-plastic grids and geotextiles close to the inner side sheet pile and the outer side sheet pile;

S5: performing secondary filling, wherein the weir body filling and the inner and outer side soil covering are performed synchronously in the filling process, and the elevation is kept consistent;

S6: pumping water in the cofferdam, simultaneously enhancing the observation of the cofferdam and checking whether each connecting piece has a problem;

s7: after the cofferdam pumping is finished, constructing the inner side protecting slope;

S8: filling the weir body after the inner slope protection of the weir is finished, and heightening the weir body;

S9: and after the bridge construction is finished, removing residues in the cofferdam, irrigating water in the cofferdam and dismantling the cofferdam.

The invention has the advantages that double rows of steel pipes are arranged in the lake after filling soil, then the steel pipes in the same row are connected together, the soil body is wrapped by the geotextile and the geogrid in the middle to form a whole body for resisting lake water from entering in all directions, after the water pumping in the cofferdam is finished, a temporary construction access way is built in the cofferdam, and the construction on the lake water is changed into land construction. Therefore, the construction sealing performance can be ensured, and pollution of mud, equipment oil stain and the like to the lake water environment can be avoided. It is worth mentioning that the construction progress of the project can be accelerated through the warehouse-dividing construction of the cofferdam, the construction cost is greatly reduced, and the construction safety factor can be improved.

in actual operation, when filling soil for the first time, the dredger digs better clay at the bottom of the lake to the transport ship, then the dredger is adopted to fill the clay at the position of the double rows of steel pipe piles by adopting the dredger, the filling width is determined according to calculation, the thickness can be filled as high as possible, the lowest filling soil exposure height of the filling soil at the weir body is ensured to be out of the water surface, and the difficulty and the times of secondary filling soil are reduced.

in a preferred embodiment of the present invention, on the basis of the foregoing, the step S2 further includes the following steps:

A1: firstly, pulling out concrete positions of an inner row of piles and an outer row of piles by using iron wires on original positioning piles of the cofferdam, and setting pile positions according to a designed interval;

a2: and B, piling by adopting an on-board excavator through the step A1, determining the depth of the pile driven into the soil layer according to design calculation, controlling the height of the pile top according to the highest water level 0.8m higher than the flood season, and driving the steel pipe pile to control the verticality.

In the actual operation of step S2, due to the closure of the double-row steel pipe pile cofferdam, zero pollution to the surrounding water area environment in the whole construction process is ensured.

Further, the step S3 further includes the following steps:

B1, adopting phi 48 steel pipes in the longitudinal direction, respectively fixing the steel pipes on two rows of steel pipe piles, controlling the elevation to be about 1m above water, adopting diagonal steel bars in the transverse direction, respectively connecting the two rows of corresponding steel pipe piles and the transverse steel pipes into a whole, and enabling each steel pile to be transversely connected;

b2: and B1, arranging transverse bridge counter-pulling steel bars at the bottom of the double-row steel pipe pile cofferdam, and reducing the cantilever length of the steel pipes.

In the actual operation of step S3, Φ 48 steel pipes are adopted in the longitudinal direction and fixed on two rows of steel pipe piles respectively, the elevation is controlled to be about 1m above water, diagonal steel bars are adopted in the transverse direction, two rows of corresponding steel pipe piles and transverse steel pipes are connected into a whole respectively, and each steel pipe pile must be connected in the transverse direction. And set up the cross-bridge at double steel-pipe pile cofferdam bottom and to the bracing reinforcing bar, reduce the cantilever length of steel pipe, avoid the bottom steel pipe to cause the steel pipe bottom to outwards throw because of the insufficient shear resistance of the soil body after going into the hardpan, avoided the soil body to subside the back and lead to the steel pipe too concentrated the buckling in the position atress of going into the hardpan.

In the practical operation of step S4, after the cofferdam framework is formed, steel-plastic grids and geotextiles are laid next to the inner and outer side sheet piles, and No. 8 iron wires are fixed on the steel pipe piles and the purlins to prevent the lake water from washing the soil in the cofferdam. Because of preventing the erosion of stormy waves to the weir body, the outer side of the cofferdam adopts double-layer geotextile to reduce the erosion of scouring force to the filled soil.

Further, the step S5 further includes the following steps:

c1: firstly, filling the center soil of the weir to ensure that the center soil of the weir is higher than the highest water level by 0.5 m;

c2: after the step C1 is set, the weir body filling and the inside and outside soil covering are carried out synchronously in the soil filling process, the elevation is kept consistent, and the inside and outside soil filling is carried out according to the following steps of: and (5) slope placing and filling at a 2-gradient.

in the actual operation of step S5, the cofferdam base is poor due to the thickness of the sludge layer, excessive filling at one time can cause excessive cofferdam settlement, the filling is controlled within 1m at one time, sludge drainage consolidation is facilitated, soil body damage caused by excessive load is prevented, and filling inside and outside the weir body is adopted to prevent uneven settlement caused by uneven filling, deformation of the steel pipe pile and slippage of the weir body.

Further, the step S7 further includes the following steps:

d1: after the water pumping of the cofferdam is finished, firstly, the engineering of filling the access and drilling platform is carried out;

d2: and D1, taking the filling sidewalk and the drilling platform as construction channels, performing elevation construction on the inner side slope protection and constructing drainage ditches, wherein the slope protection is constructed according to the gradient of 1:2, and the height of the top of the slope is about 1m from the elevation of the cofferdam top.

in the actual operation of step S8, the weir is filled after the inner slope protection is completed, the filling is performed in layers, the height of each layer is about 50cm, and the filling of the soil in the lower layer is performed after the soil layer of the weir is dry after each layer is filled, so that the settlement of the weir is reduced, and the heightening must be completed before the flood season.

further, the step S9 further includes the following steps:

e1: firstly, completely removing the connection in the cofferdam;

e2: e1, after the connection and the dismantling in the cofferdam are finished, pulling out the steel pipe pile by using a vibration hammer of the pile driving barge, pulling out the steel pipe pile from the river channel by using a winch, and hoisting the steel pipe pile by using a digging machine to transfer the steel pipe pile to the ground;

e3: and E2, after the steel pipe pile is removed, removing all soil and sundries in the river channel by using a dredger, and completely removing all cofferdam substances except the design line.

In the practical operation of the invention, before the cofferdam construction, aiming at the problem that the thickness of the sludge layer can not be removed by more than 10m, 9m wide hard soil is filled in advance to go out of the water surface, the sludge is extruded and settled stably to form a hard soil layer, so that the requirement of entering the hard soil layer by more than 3m can be met by 12m short steel pipes, the length of the steel pipes is saved, and the application range of the double-row steel pipe pile cofferdam is greatly expanded. And covering soil on the sludge layer, and driving a steel pipe pile to cover the soil for 3 m. The sand extraction area contains a sand layer due to a soil layer, the water permeability is good, under the action of high water pressure difference inside and outside the cofferdam, water permeability accidents such as piping and the like easily occur, after 9m wide covering soil is paved at the cofferdam in advance, the space between the sand layer and the silt layer is extruded through the covering soil with the thickness of 4m, the 9m wide covering soil increases the stroke of the pressure difference water inside and outside the soil layer, the pressure of the water reaching the cofferdam is reduced, and the safety of pile foundation drilling is ensured.

It will be apparent to those skilled in the art that various changes and modifications can be made without departing from the inventive concept thereof, and these changes and modifications can be made without departing from the spirit and scope of the invention.