中文摘要：

以昆明—曼谷国际公路k70路堤加固工程为背景,采用原位测试方法,完成了不同工况下预应力锚索桩板墙承载特性的现场试验。通过观测结构位移、土压力、桩身内力以及锚索预应力等,系统分析了预应力锚索桩板墙的受力特性与力学行为。锚索桩板墙对高路堤的加固效果显著,填筑初期结构位移随填土高度线性增加,锚索施工后增速有所减缓;初始填筑阶段,抗滑桩变形以刚性倾斜为主,随着锚索张拉和桩后填土不断增高桩身产生了较为明显的弯曲变形。作用在抗滑桩后的土压力大致呈三角形分布,板后土压力大致呈抛物线型分布;相同埋深条件下作用在抗滑桩上的土压力明显大于挡板,原因在于相邻抗滑桩间产生了明显的土拱效应,下部相邻抗滑桩间的土拱效应更强;与解析解的对比结果表明,实测最大桩后土压力与滑坡推力接近,远小于被动土压力;实测板后土压力与主动土压力接近,工程设计中可选取Rankine主动土压力作为挡板的设计荷载,在不利位置采取增大板厚等措施避免挡板发生破坏。采用弹性弯曲梁理论对锚索桩板墙内力计算的结果与实测结果基本一致。张拉锁定初期锚索预应力损失较大,约为设计荷载的10%,后期锚索预应力逐渐趋于稳定,锚索预应力长期损失约为设计荷载值的12%～15%。

英文摘要：

Based on the reinforcement project of k70 embankment along Kunming-Bangkok Expressway, the bearing characteristics of prestressed sheet pile wall in embankment stabilization are studied through a series of in-situ tests. The history of pile displacement, earth pressure, bending moment and prestress of cables are measured and used to illustrate the bearing characteristics and behaviors of the structure. The measured results show that the prestressed sheet pile wall significantly increases the stability of the embankment, and that the structural displacement increases linearly with the height of embankment at the beginning of backfill and then slows down with the construction of cables. The pile flexure rather than pile rotation becomes increasingly prevalent with the increasing height of filling embankment. The distribution of earth pressures exerting against the pile is triangular and that on the face of plate is parabolic. The earth pressures against the pile are systematically larger than those of plate at the same depth, which results from arching effects. The maximum value of earth pressures of the pile is close to the thrust, while the maximum value of the plate is close to the active earth pressure. Analysis of the piles using the simple elastic analysis gives that the bending moments and displacements are close to the measured ones. The test results also indicate that the percentage of loss for cables is about 10% in the short term and 12%~15% in the long term.