End Resistance Calculation and Analysis of Super-Large Open Caisson During Soil Excavation Sinking Based on Monitored Soil Pressure Data [基于土压力监测值的超大沉井下沉端阻力计算与分析]

作者：Dong X.-C.; Guo M.-W.; Jiang Z.-X.; Wang S.-L.; Chen Z.-W.

来源：Bridge Construction, 2022, 52(5): 78-84.

• Bridge engineering
• Calculation method
• Construction monitoring
• Cutting edge shape
• End resistance
• Soil excavation sinking
• Soil pressure on cutting edge
• Super-large caisson foundation

A method to accurately calculate the end resistance of different zones in super-large caisson base during soil excavation sinking is proposed. The method takes into account the shapes of the caisson cutting edges and classifies the end resistance calculation zones in accordance with shapes of cutting edges. Different reduction factors of oblique projection area are used to calculate the caisson end resistance in different calculation zones. The Changtai Changjiang River Bridge is applied as a case to study the distribution of soil pressure on cutting edges during the first soil excavation sinking of the open caisson foundation, and together with the measured data, the feasibility of the method was verified. The results show that during the caisson sinking process, the soil pressure and end resistance of cutting edges were mainly transferred from the central zone to the peripheral zones, and slight reverse transfer was found after the soil excavation in the peripheral wells. Due to that the shapes of the cutting edges are different, the reduction factors of oblique projection area corresponding to cutting edges in different zones are also varying. The recommended values of reduction factors for cutting edges with single inclined plane and with double inclined planes are 0.45 and 0.61, respectively. The relative error of the caisson end resistance calculated by the recommended reduction factors and the reduction factors derived using monitored soil pressure data is less than 9.5%, the deviation is small.

• 单位
  中国科学院大学