With the development of urban underground space, green and efficient excavation supporting structures are receiving increasing attention. Prefabricated recyclable supporting structures (PRSSs) have been developed for this reason. A deep circular excavation supported by PRSSs in low-plasticity clay (CL) was extensively instrumented to explore its deformation characteristics. Measurement results showed that the lateral displacement of the supporting piles (δ_hp) presented a typical cumulative pattern dominated by deep inward movement. The maximum lateral displacements of the supporting piles (δ_hpm) varied between 0.28%H–0.52%H (H is the excavation depth). The maximum lateral pile displacements mostly occurred above the excavation surface, ranging from H + 0.5 m to H − 7.0 m. The soils 3 m and 10 m from the excavation had the largest lateral displacement at the top and a cantilever shape. The ground surface settlements tended to follow a convex pattern. The maximum ground surface settlements (δ_vm) were normalised by the final excavation depth (H_e) on the east and south sides, and determined to be 0.43% and 0.50%, respectively. The ratio δ_vm/δ_hpm tended to increase as excavation and dewatering proceeded, with a value of 0.49–1.15. The ground surface settlement due to dewatering was 19% of the maximum settlement.

中文翻译：

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预制可循环结构支护基坑变形特性

随着城市地下空间的开发，绿色、高效的基坑支护结构日益受到关注。为此，开发了预制可回收支撑结构（PRSS）。在低塑性粘土 (CL) 中由 PRSS 支撑的深圆形开挖进行了广泛的仪器测试，以探索其变形特征。测量结果表明，支护桩的横向位移（δ _hp）呈现典型的以深度向内移动为主的累积模式。支护桩的最大横向位移（δ _hpm）在 0.28% H –0.52% H之间变化（H为开挖深度）。最大桩侧位移主要发生在开挖面上方，范围为H  +0.5m至H  -7.0m。距开挖3 m和10 m处土体顶部侧向位移最大，呈悬臂状。地表沉降倾向于遵循凸形图案。东侧和南侧的最大地表沉降（δ _{vm ）通过最终开挖深度（} He _）标准化，分别确定为 0.43% 和 0.50%。随着开挖和脱水的进行， δ _vm / δ _hpm之比呈增大趋势，值为 0.49~1.15。脱水引起的地表沉降量为最大沉降量的19%。