CN214423184U

CN214423184U - Be applied to hasp steel-pipe pile cofferdam under water level variation condition

Info

Publication number: CN214423184U
Application number: CN202120010498.5U
Authority: CN
Inventors: 王森; 高明慧; 孙宏伟; 高学文; 赵江; 滕云龙; 丁哲臻; 裴野; 向敏; 宋哲; 曹绍渤
Original assignee: First Engineering Co Ltd of China Railway Construction Bridge Engineering Bureau Group Co Ltd
Current assignee: First Engineering Co Ltd of China Railway Construction Bridge Engineering Bureau Group Co Ltd
Priority date: 2021-01-05
Filing date: 2021-01-05
Publication date: 2021-10-19
Anticipated expiration: 2031-01-05

Abstract

The utility model discloses a be applied to hasp steel-pipe pile cofferdam under water level variation condition, its characterized in that: the cofferdam is formed by encircling a plurality of first sections of steel pipe piles (1), adjacent first sections of steel pipe piles (1) are connected with each other through lock catches (2), the tops of the first sections of steel pipe piles (1) are connected with second sections of steel pipe piles (4) in a higher mode, the adjacent second sections of steel pipe piles (4) are also connected with each other through lock catches (2), grouting gravel parts (11) are filled in gaps between the bottoms of the first sections of steel pipe piles (1) and pilot holes, the grouting gravel parts (11) are formed by gravel and solidified cement slurry, yellow mud parts (12) are filled above the grouting gravel parts (11), one or more inner supports are further arranged on the inner sides of the steel pipe piles, and the inner supports are formed by steel purlins, inner diagonal braces and inner transverse braces which are connected with each other.

Description

Be applied to hasp steel-pipe pile cofferdam under water level variation condition

Technical Field

The utility model relates to a bridge construction field, especially a be applied to hasp steel-pipe pile cofferdam under water level variation condition.

Background

The deep water foundation construction is the key and difficult point of deep water bridge construction, the deep water foundation construction method and construction technology in China are rapidly developed, and the problems and challenges in the foundation construction are continuously increased. The construction method generally adopted by deepwater foundation construction is to install cofferdams for foundation pit excavation operation, the cofferdams comprise earth-rock cofferdams, double-wall steel box cofferdams, steel sheet pile cofferdams, steel pipe pile cofferdams and the like, and the cofferdams are determined according to factors such as the thickness of a field covering layer, the properties of a soil layer, the water depth and water level change, the water flow speed and the like.

When the covering layer is thick and the covering layer is a pebble soil layer with a large particle size, the problem that the sleeve cannot directly cut soil and sink when the double-wall steel sleeve box cofferdam is applied is solved, and the steel plate pile cofferdam or the lock catch steel pipe pile cofferdam is preferably selected. For the steel sheet pile cofferdam, when water level constantly changes and the depth of water is darker in season, it is better to select for use hasp steel-pipe pile cofferdam stability, and bending resistance is bigger. And the steel quantity for the lock catch steel pipe pile cofferdam is small, the weight of the processed single component is small, the processing is simple, the transportation and the assembly are convenient, the requirement on hoisting equipment is low, and the lock catch steel pipe pile cofferdam is more suitable for complex environments. However, because the pebble particle size is large and the ground floor is hard, the construction process requirements of water stopping, inserting driving and connecting of the lock catch steel pipe pile are high, and the construction difficulty is large. Due to the reasons, the traditional lock catch steel pipe pile cofferdam cannot be directly applied to the environment with water level change and super-thick pebble covering layer conditions.

SUMMERY OF THE UTILITY MODEL

The utility model relates to a solve the above-mentioned not enough that prior art exists, provide one kind and can improve the efficiency of construction, reduce construction cost, can solve to the thick and constantly changing hasp steel-pipe pile cofferdam of inlaying rock foundation construction under water level of cobble overburden.

The technical solution of the utility model is that: the utility model provides a be applied to hasp steel-pipe pile cofferdam under water level variation condition which characterized in that: the cofferdam is formed by encircling a plurality of first sections of steel pipe piles 1, the adjacent first sections of steel pipe piles 1 are connected with each other through lock catches 2, the tops of the first sections of steel pipe piles 1 are connected with second sections of steel pipe piles 4 in a high mode, the adjacent second sections of steel pipe piles 4 are also connected with each other through lock catches 2, grouting gravel parts 11 are filled in gaps between the bottoms of the first sections of steel pipe piles 1 and guide holes, the grouting gravel parts 11 are formed by gravel and solidified cement slurry, yellow mud parts 12 are filled above the grouting gravel parts 11, one or more inner supports are further arranged on the inner sides of the steel pipe piles, and each inner support is formed by a steel purlin, an inner diagonal brace and an inner transverse brace which are connected with each other.

Compared with the prior art, the utility model, have following advantage:

compared with the prior art, the structure form of the locking steel pipe pile cofferdam applied to the water level change condition provides a brand new structure, and enriches the construction method of the locking steel pipe pile cofferdam foundation construction. On one hand, the problem of inserting and beating the steel pipe under the complex geological condition that the pebble covering layer is thick and the covering layer is pebble soil with large grain diameter can be solved; on the other hand, it can also guarantee the smooth proceeding of the foundation construction under the season water level change. Due to the steel pipe pile cofferdam with the structure, the lock catch steel pipe pile can be directly applied to the condition of water level change, and due to the short processing period of the lock catch steel pipe pile, the manufacture is convenient, and the requirements on hoisting equipment for transportation and assembly are low, so the construction difficulty is reduced, and the construction period is also saved; and after the construction is finished, the steel pipes in the lock catch steel pipe pile cofferdam can be recycled, so that the purchase cost and the turnover cost of cofferdam equipment are reduced in the long term, and the total construction cost of the bridge foundation is reduced. Therefore, the lock catch steel pipe pile cofferdam and the construction method thereof have multiple advantages, are particularly suitable for popularization and application in the field, and have wide market prospects.

Drawings

Fig. 1 is the utility model discloses the structural schematic of hasp steel-pipe pile cofferdam of embodiment.

Fig. 2 is a schematic view of a half elevation of foundation pit excavation and cushion cap construction in the cofferdam construction of the latched steel pipe pile of the embodiment of the present invention;

fig. 3 is a schematic half-side view of foundation pit excavation and cushion cap construction in the cofferdam construction of the latched steel pipe pile of the embodiment of the present invention;

fig. 4 is a schematic plan view of foundation pit excavation and bearing platform construction in the lock catch steel pipe pile cofferdam construction of the embodiment of the present invention;

FIG. 5 is an enlarged view of the structure at A in FIG. 4;

fig. 6 is a schematic view of a reaction strut.

Detailed Description

The following description will explain embodiments of the present invention with reference to the drawings. As shown in fig. 1 to 6: a lock catch steel pipe pile cofferdam applied to water level change condition is formed by surrounding a plurality of first sections of steel pipe piles 1, adjacent first sections of steel pipe piles 1 are connected with each other through lock catches 2, the top of the first section of steel pipe pile 1 is connected with a second section of steel pipe pile 4 in a higher mode, adjacent second sections of steel pipe piles 4 are also connected with each other through lock catches 2, a grouting gravel part 11 is filled in a gap between the bottom of the first section of steel pipe pile 1 and a pilot hole, the grouting gravel part 11 is formed by gravel and solidified cement slurry, a yellow mud part 12 is filled above the grouting gravel part 11, namely, the gravel is filled in a gap between the bottom of the first section of steel pipe pile 1 and the pilot hole, then yellow mud is filled in the gap above the gravel to form the yellow mud part 12, the yellow mud part 12 is formed, a pilot pipe is led to the gravel part, the cement slurry is poured into the gravel part through the pilot pipe, the cement slurry is solidified to form a grouting gravel part 11; one or more inner supports are further arranged on the inner side of the steel pipe pile, and each inner support is composed of a steel purlin, an inner inclined strut and an inner cross strut which are connected with one another.

When the buckling steel pipe pile cofferdam is constructed, the steps are carried out according to the following sequence:

in the dry season, construction preparation is carried out, a temporary overwater steel trestle is built outside the cofferdam to serve as a cofferdam construction platform,

after measurement and positioning, a rotary drill is adopted to drill a pilot hole, the diameter of the pilot hole is larger than 50cm of the pile diameter of the first section of the steel pipe pile 1, a steel casing is lowered down by the rotary drill during pilot hole, the steel casing follows up to a rock stratum, the rock stratum is drilled by a percussion drill to reach the design depth,

after the first pilot hole is finished, soil layer replacement filling at the bottom of the pilot hole is carried out, soil body at the bottom of the pile within the range of the rock layer is replaced and filled with broken stones to form a broken stone part 11, the broken stone part is formed by 2-4cm of broken stones, soil layer at the upper part of the broken stones is replaced and filled with yellow mud to form a yellow mud part 12, the steel casing is pulled out after replacement filling is finished, construction and replacement filling operation of the next pilot hole are carried out, and an overlapping part exists between the apertures of the adjacent pilot holes,

after soil layers of all the guide holes are filled and replaced, inserting and driving of the lock catch steel pipe piles are carried out, firstly, a positioning guide frame is installed at the guide holes, the center of each steel pipe pile is ensured to be aligned with the center of a drill hole under the action of the positioning guide frame, a first section of steel pipe pile 1 is inserted and driven into a designed position of the soil layer by using a vibration hammer, after the first section of steel pipe pile 1 is inserted and driven in place, the pile head of the first section of steel pipe pile 1 is required to be higher than the water surface, the operation is carried out until all the first section of steel pipe pile 1 surrounds to form a first section of steel pipe pile cofferdam, and the adjacent first sections of steel pipe piles 1 are connected with each other through lock catches 2,

grouting the pile bottom after all the first steel pipe piles 1 are inserted and driven, grouting the gravel layer between the bottom of the first steel pipe pile 1 and the pilot hole, grouting through a grouting pipe embedded at the bottom, strengthening water stopping, strengthening the stability of the bottom of the first steel pipe pile 1, completing the first steel pipe pile cofferdam,

constructing a main pier concrete filling pile 3 while constructing a first section of steel pipe pile cofferdam, building a drilling platform inside the first section of steel pipe pile cofferdam, embedding a steel pile casing, drilling by adopting a rotary drilling rig, lowering a steel reinforcement cage after hole cleaning, filling underwater concrete,

after the main pier concrete filling piles 3 are completely constructed, all the construction machines in the first section of steel pipe pile cofferdam are withdrawn, the drilling platform is dismantled, cofferdam heightening is carried out, a second section of steel pipe pile 4 is connected to the top end of each first section of steel pipe pile 1 to form a heightened cofferdam,

pumping water and excavating in the heightened cofferdam, installing the inner supports, pumping water and excavating the foundation pit to a position 0.5m below the first inner support when the first inner support is installed, then installing the first inner support consisting of a first layer of steel purlin 5, a first inner inclined strut 6 and a first inner cross strut 7, installing the next inner support according to the circulation after the installation is finished, and installing three inner supports in total,

excavating the foundation pit to a position 3m below the bottom of the bearing platform, breaking off the pile head, pouring bottom sealing concrete 8,

after the bottom sealing concrete 8 reaches the design strength, carrying out bearing platform construction, wherein the bearing platform is poured in two layers, firstly binding a first layer of bearing platform reinforcing steel bars, pouring a first layer of bearing platform 9, after the concrete of the first layer of bearing platform 9 reaches the design strength, filling sand in a gap between the first layer of bearing platform 9 and the first section of steel pipe pile 1 to form a sand filling layer 10, then pouring a concrete ring beam 13 above the sand filling layer 10, removing a third inner support after the concrete ring beam 13 reaches the design requirement, binding a second layer of bearing platform reinforcing steel bars to pour a second layer of bearing platform 14, wherein the construction steps of the second layer of bearing platform 14 are the same as those of the first layer of bearing platform 9,

after the construction of the bearing platform is finished and the design requirement is met, the construction of the tower base is carried out, the support replacement of the second inner support is carried out after the construction of the tower base is finished, the reaction support 15 is arranged for temporary support during support replacement, after the concrete of the tower base reaches the design strength, one end of the reaction support 15 is supported on the tower base, the other end of the reaction support 15 is connected with the first layer of steel surrounding purlin 5, the support replacement is finished after the installation of the reaction support 15, then the second inner support is removed,

constructing the first section of the lower tower column, when the first section of the lower tower column is constructed to the position of the first inner support, carrying out inner support replacement in the same way as the previous step, when the counter-force support 15 is propped against the tower column after replacement, dismantling the first inner support, continuing construction until the lower tower column is higher than the water surface, and thus completing the construction of the underwater part,

and after the underwater part is constructed, removing the heightened cofferdam, and removing all the inner supports in sequence from top to bottom when the heightened cofferdam is removed, wherein the steel pipe pile only removes the part above the riverbed.

The grouting pipe is required to be put down before the cofferdam foundation pit soil layer is replaced and filled, and the grouting pipe is required to be sealed and protected before putting down,

the grouting pipes are arranged on two sides of the steel pipe pile and arranged at the outer edge of the guide hole.

The foundation pit excavation step is symmetrical excavation.

Claims

1. The utility model provides a be applied to hasp steel-pipe pile cofferdam under water level variation condition which characterized in that: the cofferdam is formed by encircling a plurality of first sections of steel pipe piles (1), adjacent first sections of steel pipe piles (1) are connected with each other through lock catches (2), the tops of the first sections of steel pipe piles (1) are connected with second sections of steel pipe piles (4) in a higher mode, the adjacent second sections of steel pipe piles (4) are also connected with each other through lock catches (2), grouting gravel parts (11) are filled in gaps between the bottoms of the first sections of steel pipe piles (1) and pilot holes, the grouting gravel parts (11) are formed by gravel and solidified cement slurry, yellow mud parts (12) are filled above the grouting gravel parts (11), one or more inner supports are further arranged on the inner sides of the steel pipe piles, and the inner supports are formed by steel purlins, inner diagonal braces and inner transverse braces which are connected with each other.