Construction method of unsealed concrete combined cofferdam under rock geological conditions

Abstract

The invention discloses a modular coffer construction method for concrete without subsealing in the geologic condition of stratum: Firstly, a strutting piece and a guide frame are welded all around the outside of a steel barrel of a prepared cushion cap; Secondly, a lock steel pipe pile is downwards inserted along the guide frame, and the bottom of the lock steel pipe pile should reach the surface of a strong weathered rock; Thirdly, the inner of the steel pipe pile is downwards excavate vortically by a rotary drill rig, after deepening to the inner of a weak weathered rock, a drilled pile on the bottom of the steel pipe pile is constructed; Fourthly, after finishing all the drilled piles on the bottom of the steel pipe pile, a closed coffer is formed; Then, the river water in the coffer is drawn out and a support is installed in the coffer; After that, a submerged pump is arranged in coffer to draw out the percolating water, and then a foundation cleaning is dug by a digger to the bottom of the cushion cap; Finally, the concrete cushion is poured to the bottom of the cushion cap, and the cushion cap construction can be finished in the waterless and dry environment. The construction method has the advantages that the stratum does not need to be blown up under the water, the construction difficulties and amount are reduced, the whole stability of the coffer is strong, and the construction efficiency is high.

Description

technical field [0001] The invention relates to bridge deep-water foundation construction technology, in particular to a bridge deep-water foundation construction technology. Background technique [0002] In the process of deep water bridge foundation construction, when there is an existing building foundation nearby, in order to increase the safety distance as much as possible and ensure the safety of the existing building, the steel pipe pile cofferdam has strong mechanical performance and Obvious size advantage. During normal steel pipe pile cofferdam construction, the technological process is as follows: according to the design of the steel pipe pile cofferdam, the steel pipe piles and locks are processed and assembled; sinking steel pipe piles (install guide frames around the construction platform, control the According to the inclination of the pile, the position of each steel pipe pile is set out on the guide frame according to the theoretical size, and it is hit in ...

AI Technical Summary

Problems solved by technology

However, when the excavation depth of the foundation pit is deep in the geological conditions of the rock formation, due to the high hardness of the rock formation, it is difficult to insert the steel pipe pile cofferdam, and it is difficult for the roots to drive into the rock surface to take root, which leads to the instability of the cofferdam structural system and cannot meet its requirements. Force requirements

If underwater blasting is carried out on rock formations, it will not only threaten the existing buildings nearby, but also pollute water resources with chemical explosives, and the investment in equipment will be high.

Images