卸荷式板桩结构性能试验研究*

卸荷式板桩具有极其复杂的荷载传递方式与协调工作机理，因此探索其结构的承载力性能意义重大。结合工程 案例进行现场实测以研究其承载力特性。结果表明：该结构墙身在16 m处水平位移量随着时间的推移而逐渐增大并趋于稳 定，锚锭墙整体最大水平位移发生在锚锭点处；拉杆拉力在浚深挖泥初期有较大幅度的增加而后期拉杆内力趋于稳定；侧 向土压力分布近似服从静止土压力分布；超静孔隙水压力在主动区-20 m以上有所减小而被动区-20 m以下略有增大。试验 研究证明该新型卸荷式板桩具备良好的承载力机理与工作性能，可广泛应用于大型复杂的深水码头等工程。

Experimental study on structural performances of unloading sheet piles

The unloading type sheet pile has enormous complexity of load transfer method and coordination mechanism, thus exploring the structure of the bearing capacity performance is of great significance, especially the bearing capacity characteristics are studied by combining with specific engineering cases for the field measurement. The results show that the walls in the 16 m at the amount of horizontal displacement over time are gradually increased and stabilized, and the overall maximum horizontal displacement of the anchor wall occurs at the anchor point. Drawbar pull is substantially increased in the early deep dredging period, and tends to be steady in the later period. The distribution of lateral earth pressure is approximately determined by the distribution of earth pressure at rest, and the fluctuation is due to uneven distribution of various soil and interlayer, but the overall trend remains unchanged. The excess pore water pressure is reduced at the height of -20 m or more in the active region, following a slight increase under the height of -20 m in the passive zone. All results show that the unloading sheet pile has high bearing capacity mechanism and working performance functions, and can be widely used in large-scale complex deepwater pier projects.