阅读说明：本技术 一种复合围堰施工方法 (Composite cofferdam construction method ) 是由 熊卫根 王胜利 孙建 娄剑锋 孙超 张太山 徐为 黄建云 李芃蓁 胡鹏 于 2019-08-29 设计创作，主要内容包括：本发明公开了一种复合围堰施工方法,包括测量放样、搭设施工钢平台、钻孔灌注桩施工、现浇纵梁、安装挡泥钢板、高压旋喷桩施工、现浇横梁、填充袋装黄土、安装预制面板、现浇面层这些施工步骤,施工时,该复合围堰采用在两排灌注桩的内侧壁上设置挡泥钢板,且在两挡泥钢板之间采用高压旋喷桩和袋装黄土填充的方式,提高了围堰对侧向水压力的阻挡承受能力,同时,使得该围堰具备较强的抗渗能力,解决了常规单一的挡水围堰所不能解决的问题,使得围堰能适应复杂水文地质环境,该施工方法能有效确保围堰的施工质量和安全。(The invention discloses a composite cofferdam construction method, which comprises the construction steps of measuring and lofting, building a construction steel platform, constructing bored piles, casting longitudinal beams in situ, installing mud blocking steel plates, constructing high-pressure jet grouting piles, casting cross beams in situ, filling bagged loess, installing prefabricated panels and casting surface layers in situ.)

1. The construction method of the composite cofferdam is characterized by comprising the following steps:

s1, measurement lofting: determining pile positions of pile foundations by adopting GPS positioning;

s2, building a construction steel platform: comprises a platform pile foundation, a longitudinal beam (5) and a platform panel;

s3, construction of the cast-in-situ bored pile (1): after the platform is built, sinking and drilling the steel casing of the cast-in-situ bored pile (1), drilling, installing a steel fine cage, pouring concrete and chiseling a pile head;

s4, casting longitudinal beams in situ: pouring is completed through a formwork system on the basis of the cast-in-situ bored pile (1);

s5, installing a mud-blocking steel plate (2): a plurality of mud-blocking steel plates (2) are vertically arranged on the side walls of the two rows of cast-in-situ bored piles (1), and a water-blocking cofferdam is formed by the mud-blocking steel plates (2);

s6: constructing the high-pressure jet grouting pile (3): a longitudinal beam is used as a supporting beam, a high-pressure jet grouting pile (3) pile machine is installed, and a soft foundation between two rows of mud blocking steel plates is replaced by a cement curtain wall to form the lower half part of the water blocking cofferdam;

s7, casting a beam in situ: the longitudinal beams are used as supporting beams, the beam cast-in-place formwork supporting system is reversely hung, and concrete pouring is carried out after the reinforcement is bound;

s8, filling the bagged loess (4): filling the bagged loess (4) between the two mud-stopping steel plates (2) to form the upper half part of the water-retaining cofferdam;

s9, mounting the prefabricated panel (6): mounting a prefabricated panel (6) to form a platform on the top of the water retaining cofferdam;

s10, casting a surface layer in situ: and (5) pouring a concrete surface layer on the prefabricated panel (6) to finish construction.

2. The composite cofferdam construction method according to claim 1, characterized in that: when setting up the construction steel platform, regard circular steel pipe as the platform pile foundation, adopt the vibratory hammer to sink into the soil layer under water, at the shaped steel of two-layer perpendicular distribution of platform pile foundation top installation as vertical beam, carry out the installation of platform panel after the longitudinal and transverse beams has installed, platform pile foundation, vertical beam, platform panel all need keep away drilling bored concrete pile (1) pile position when the construction, reserve drilling bored concrete pile (1) construction space.

3. A composite cofferdam construction method according to claim 1 or 2, characterized in that: the platform panel is a patterned steel plate.

4. The composite cofferdam construction method according to claim 1, characterized in that: when the cast-in-situ bored pile (1) is constructed, a drilling machine suitable for geological conditions is adopted for drilling, hole cleaning is carried out after the drilling is finished, a reinforcement cage is placed after the hole cleaning is qualified, and then concrete pouring is carried out.

5. The composite cofferdam construction method according to claim 1, characterized in that: when the longitudinal beam is cast in place, the steel hoop, the I-shaped steel (10) and the square wood bars are combined into a template supporting system, and a bottom template and a side template are installed on the basis, so that concrete is poured after steel bars are bound.

6. The composite cofferdam construction method according to claim 1, characterized in that: when installing fender mud steel sheet (2), fender mud steel sheet (2) insert former mud face and are no less than 0.5m, and fender mud steel sheet (2) top surface elevation is the same with longeron end elevation, and the overlap joint between two adjacent fender mud steel sheet (2) is located by drilling bored concrete pile (1), and 0.5m is no less than to the overlap joint.

7. The composite cofferdam construction method according to claim 1 or 6, characterized in that: the mud guard steel plate (2) is hung and installed in place by a 10t hoist (9).

8. The composite cofferdam construction method according to claim 1, characterized in that: the thickness of the surface layer of the poured concrete is 5-8 cm.

Technical Field

The invention relates to the technical field of hydraulic engineering construction, in particular to a construction method of a composite cofferdam.

Background

At present, dock engineering is basically constructed near water, dry construction conditions need to be guaranteed in the dock during construction, a temporary water retaining wall can be arranged to form a water retaining cofferdam at the near water side of the dock, accumulated water in the dock is drained after the cofferdam is formed, the dock is guaranteed to smoothly enter a dry operation state, and construction safety and quality are guaranteed. When the cofferdam is constructed, the position of the cofferdam is basically in water, and the water construction is needed.

Due to the long-term development and utilization of ocean and river shoreline resources, at present, most newly-built docks are under complex hydrogeological conditions, and due to the fact that a large water head difference exists between the shoreside and the water side and the influence of water flow and sudden waves, the cofferdam needs to bear great lateral water pressure, and under the geological conditions that rock strata and soft soil layers are staggered and mixed, the requirement on the anti-permeability capacity of the cofferdam is higher. Therefore, under the complex hydrogeological conditions, the conventional cofferdam with a single structure is difficult to meet the purpose of water retaining, so that a composite cofferdam which meets the mechanical property and has certain anti-permeability capacity needs to be designed in a targeted manner.

When the cofferdam is constructed in seawater, the cofferdam is influenced by the environment such as wind waves, tides and the like during construction, so a set of feasible construction method needs to be established in a targeted manner to ensure the construction quality and safety of the cofferdam.

Disclosure of Invention

Aiming at the problems in the prior art, the composite cofferdam construction method is provided, which not only can improve the capability of the cofferdam for bearing lateral water pressure, but also can improve the anti-permeability capability of the cofferdam.

The specific technical scheme is as follows:

the construction method of the composite cofferdam is characterized by comprising the following steps:

s1, measurement lofting: determining pile positions of pile foundations by adopting GPS positioning;

s2, building a construction steel platform: comprises a platform pile foundation, a longitudinal beam and a platform panel;

s3, construction of the cast-in-situ bored pile: after the platform is built, sinking, drilling, installing a reinforcement cage, pouring concrete and chiseling a pile head of the cast-in-situ bored pile steel casing;

s4, casting longitudinal beams in situ: pouring is completed through a formwork system on the basis of the cast-in-situ bored pile;

s5, mounting a mud guard steel plate: a plurality of mud-blocking steel plates are vertically arranged on the side walls of the two rows of cast-in-situ bored piles, and the mud-blocking steel plates enclose a water-blocking cofferdam;

s6: constructing a high-pressure jet grouting pile: the longitudinal beam is used as a supporting beam, a high-pressure jet grouting pile machine is installed, and a soft foundation between two rows of mud blocking steel plates is replaced by a cement curtain wall to form the lower half part of the water blocking cofferdam;

s7, casting a beam in situ: the longitudinal beams are used as supporting beams, the beam cast-in-place formwork supporting system is reversely hung, and concrete pouring is carried out after the reinforcement is bound;

s8, filling the bagged loess: filling the bagged loess between the two mud-stopping steel plates to form the upper half part of the water-retaining cofferdam;

s9, mounting the prefabricated panel: mounting a prefabricated panel to form a platform at the top of the water retaining cofferdam;

s10, casting a surface layer in situ: and pouring a concrete surface layer on the prefabricated panel to finish construction.

Preferably, when setting up the construction steel platform, regard circular steel pipe as the platform pile foundation, adopt the vibration hammer to sink into the soil layer under water, at the shaped steel of two-layer perpendicular distribution of platform pile foundation top installation as the longitudinal girder, carry out the installation of platform panel after the longitudinal girder and transverse girder has been installed, platform pile foundation, longitudinal girder, platform panel all need avoid drilling bored concrete pile position when the construction, reserve drilling bored concrete pile construction space.

Preferably, the platform panel is a pattern steel plate.

Preferably, when the cast-in-situ bored pile is constructed, a drilling machine suitable for geological conditions is adopted for drilling, hole cleaning is carried out after the drilling is finished, a reinforcement cage is placed after the hole cleaning is qualified, and then concrete pouring is carried out.

Preferably, when the longitudinal beam is cast in place, the steel hoop, the I-steel and the square wood bars are combined into a template supporting system, and the bottom template and the side template are installed on the basis, so that concrete is poured after the steel bars are bound.

Preferably, when installing the fender mud steel sheet, the fender mud steel sheet inserts former mud face and is no less than 0.5m, and fender mud steel sheet top surface elevation is the same with longeron end elevation, and the overlap joint between two adjacent fender mud steel sheets is located by the bored concrete pile, and 0.5m is no less than to the overlap joint.

Preferably, the mud guard steel plate is hung and installed in place by a 10t hoist.

Preferably, the thickness of the cast concrete surface layer is 5-8 cm.

The positive effects of the technical scheme are as follows:

according to the composite cofferdam disclosed by the invention, the mud blocking steel plates are arranged on the inner side walls of two rows of filling piles, and a high-pressure jet grouting pile and bagged loess filling mode is adopted between the two mud blocking steel plates, so that the blocking bearing capacity of the cofferdam on lateral water pressure is improved, meanwhile, the cofferdam has stronger anti-permeability capacity, the problem which cannot be solved by a conventional single water blocking cofferdam is solved, the cofferdam can adapt to a complex hydrogeological environment, and the construction quality and safety of the cofferdam can be effectively ensured by the construction method.

Drawings

FIG. 1 is a plan view of a composite cofferdam of the present invention;

FIG. 2 is a cross-sectional view of the west cofferdam of the present invention;

FIG. 3 is a cross-sectional view of the north cofferdam of the present invention;

fig. 4 is a schematic view showing the suspended installation of the fender according to the present invention.

In the attached drawings, 1, filling piles; 2. a mud guard steel plate; 3. high-pressure jet grouting piles; 4. bagging loess; 5. a longitudinal beam; 6. prefabricating a panel; 7. a support bar; 8. auxiliary piles; 9. hoisting a hoist; 10. and (4) H-shaped steel.

Detailed Description

In order to make the technical means, the creation features, the achievement purposes and the effects of the invention easy to understand, the following embodiments are provided for specifically describing the invention with the attached drawings.

FIG. 1 is a plan view of a composite cofferdam of the present invention; FIG. 2 is a cross-sectional view of the west cofferdam of the present invention; FIG. 3 is a cross-sectional view of the north cofferdam of the present invention; fig. 4 is a schematic view showing the suspended installation of the fender 2 according to the present invention. Please combine fig. 1 to fig. 3, which illustrate a structure of a composite cofferdam, specifically including two rows of bored concrete piles 1 vertically arranged, two rows of the side walls of the bored concrete piles 1 are vertically provided with a plurality of mud blocking steel plates 2, a plurality of mud blocking steel plates 2 enclose a water blocking cofferdam, the bottom of the water blocking cofferdam is filled with a high-pressure jet grouting pile 3, namely a cement slurry layer, the top of the cement slurry layer is filled with bagged loess 4, the pile top of the bored concrete pile 1 is provided with longitudinal beams 5 which are connected into a whole to form a stable frame structure, and the longitudinal beams 5 are provided with prefabricated panels 6 to form a construction platform. This composite cofferdam adopts fender mud steel sheet 2 and cement slurry layer and 4 packing settings of loess in bags, can not only effectively improve the ability that the cofferdam bore side direction water pressure, can also improve the impervious ability of cofferdam.

In order to further enhance the capability of bearing the lateral water pressure of the water-retaining cofferdam, a plurality of support rods 7 are obliquely arranged on the inner side (namely, the side close to the land) of the water-retaining cofferdam, the upper ends of the support rods 7 are connected with the base of the longitudinal and transverse beams 5, and the lower ends of the support rods 7 are connected with the base on the land, so that the lateral water pressure can be effectively resisted.

And in order to further enhance the lateral water pressure resistance of the water-retaining cofferdam on the seawater side, an auxiliary pile 8 is obliquely arranged between the two cast-in-place piles 1 on the seawater side, and the auxiliary pile 8 is a prefabricated pile foundation.

The construction method of the composite cofferdam comprises the following steps:

s1, measurement lofting: and the pile position of the pile foundation is determined by adopting GPS positioning, so that the pile position of the pile foundation is accurate.

S2, building a construction steel platform: the platform comprises a platform pile foundation, a longitudinal beam, a transverse beam and a platform panel. This platform adopts the vibratory hammer to sink into in the soil layer under water as the platform pile foundation by circular steel pipe, installs two-layer vertical distribution's shaped steel as vertical cross beam at platform pile foundation top, carries out the panel installation after vertical and horizontal roof beam has installed, and the platform panel generally chooses for use the decorative pattern steel sheet. The platform pile foundation, the longitudinal beam and the panel are all kept away from the pile position 1 of the cast-in-situ bored pile during construction, and the construction space 1 of the cast-in-situ bored pile is reserved.

S3, construction of the cast-in-situ bored pile 1: after the platform is built, sinking the steel casing of the cast-in-situ bored pile 1, drilling, installing a reinforcement cage, pouring concrete, chiseling a pile head and the like, and similarly sinking the pile head in place by adopting a vibration hammer. And drilling by adopting a drilling machine suitable for geological conditions, cleaning holes after drilling, transferring the reinforcement cage after cleaning the holes is qualified, and then pouring concrete.

S4, casting longitudinal beams in situ: the cast-in-place pile is cast by a formwork system on the basis of the cast-in-place pile 1, specifically, a formwork support system is combined by a steel hoop, I-shaped steel 10 and square wood bars, a bottom formwork and a side formwork are installed on the basis, and concrete is cast after steel bars are bound.

S5, mounting the mud-blocking steel plate 2: the side walls of the two rows of cast-in-situ bored piles 1 are vertically provided with a plurality of mud-blocking steel plates 2, and the mud-blocking steel plates 2 enclose a water-blocking cofferdam. During construction, the mud guard steel plate 2 is inserted into the original mud surface and is not less than 0.5m, and the elevation of the top surface of the mud guard steel plate 2 is the same as the elevation of the bottom of the longitudinal beam. The lap joint between two adjacent fender mud steel sheet 2 is located by drilling bored concrete pile 1, and the overlap joint is no less than 0.5 m. The mud-guard steel plate 2 is hung and installed in place by a 10t hoist 9, and the specific hanging mode is shown in figure 4.

S6, constructing the high-pressure jet grouting pile 3: a longitudinal beam is used as a supporting beam, a high-pressure jet grouting pile 3 pile machine is installed, and a soft foundation between two rows of mud blocking steel plates is replaced by a cement curtain wall to form the lower half part of the water blocking cofferdam.

S7, casting a beam in situ: and (3) taking the longitudinal beam as a supporting beam, reversely hoisting the beam cast-in-place formwork supporting system, and pouring concrete after finishing binding the reinforcing steel bars.

S8, filling the bagged loess 4: and filling the bagged loess 4 between the two mud-stopping steel plates 2 to form the upper half part of the water-retaining cofferdam.

S9, mounting the prefabricated panel 6: and (4) mounting the prefabricated panel 6 by using a crane to form a platform on the top of the water-retaining cofferdam.

S10, casting a surface layer in situ: and (5) pouring a concrete surface layer with the thickness of 5-8cm to finish construction.

Through the technical scheme, compared with the prior art, the invention has the following advantages: according to the composite cofferdam disclosed by the invention, the mud blocking steel plates 2 are arranged on the inner side walls of two rows of filling piles 1, and a mode of filling high-pressure jet grouting piles 3 and bagged loess 4 is adopted between the two mud blocking steel plates 2, so that the blocking bearing capacity of the cofferdam on lateral water pressure is improved, meanwhile, the cofferdam has stronger anti-permeability capacity, the problem which cannot be solved by a conventional single water blocking cofferdam is solved, the cofferdam can adapt to a complex hydrogeological environment, and the construction quality and safety of the cofferdam can be effectively ensured by the construction method.

While the invention has been 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.