Research On New Construction Technology Of Bucket Foundation Structure

Bucket foundation structure, suitable for soft foundation, used to build breakwaters and wharves, has superiority in simplifying foundation construction by omitting a series of construction procedure, such as foundation trench dredging, rubble, fortifying and leveling foundation, compared with traditional coastal engineering structures. Furthermore, it is a new structure worthy of promotion for short field operation time, low risk and cost. However, the existing transportation technique of bucket foundation structure is to transport bucket foundation structure which are prefabricated one by one onshore and assembled on semi-submersible barge. This technique presents several problems such as high cost, long field operation time and low efficiency.This paper presents a new construction method of Bucket foundation structure: prefabricating structures one by one onshore, building a simple underwater platform, then assembling structures by the use of tidal range, and then floating the structure to the installation site in the high tide. Since the method assembles structures by means of a tidal range, the connection wall between the base cylinders becomes shorter, reducing the overall structural strength to some extent. In this paper, FE software ABAQUS was adopted to study the force of the improved bucket foundation structure in the key steps of the new construction method, based ne the background of a desalination project in Tianjin port.Firstly, FE software ABAQUS was applied to simulate the improved bucket foundation structure in the case of long-term use conditions under waves to verify the safety. Then the construction works using negative pressure to level the structure when the structure skewed in the process of sinking were simulated, the internal forces were analyzed, and the suggestion about ensuring structural strength was proposed. Finally, the stability of the structure during floating process was simulated to verify the floating stability, analyze internal force when swinging and propose a suggestion of ensuring structural strength.The practicality of assembling underwater was verified. The construction cost declines due to skipping the usage of large construction vessels, e.g. semi-submersible barge. Based on this, the new construction method can be applied in modern harbor engineering.