Soil Taking and Sinking Construction Technology of Open Caisson for Changtai Yangtze River Bridge No.5 Pier
The main bridge of Changtai Yangtze River Bridge is a double-deck steel truss girder cable-stayed bridge.The No.5 pier adopts a step-shaped open caisson with a round-ended section,during the sinking process of the caisson,it needs to cross the silty clay and silt interbedded layer.Before the open caisson is implanted,the riverbed is pre-excavated to remove the surface hard plastic silty clay,and then the stepped process is used to take the soil and sink.Firstly,the soil is taken from the inner ring well hole to eliminate the cross joint and the inner partition wall support,and then the outer ring soil is taken to further weaken the open caisson end support,and the soil of the inner and outer rings are alternately taken to form a stepped mud surface to keep the open caisson sinking posture stable.The intelligent gas lift soil taking equipment is developed,based on the intelligent auxiliary decision-making algorithm,the construction instructions are issued intelligently,and the soil taking equipment is operated automatically to realize the efficient soil taking in the borehole range.With the help of high-pressure jet grouting,air-water composite jet and other soil breaking methods,the blind area support such as partition wall and shaft wall under special strata is actively eliminated.Through the sinking inversion analysis,the relationship between the sinking coefficient and the sinking rate is calculated,and the open caisson is controlled to sink steadily to the design elevation.
NETL
NSTL
万方数据
维普
