Canadian Geotechnical Journal, Ahead of Print.
Bidirectional static loading tests were conducted on two strain-gage instrumented barrettes installed to 72 m depth in Ho Chi Minh City, Vietnam. The barrettes were to support a 16-storey building with 5 basements. The soil profile comprised layers of medium coarse to fine sand, medium clay, firm to stiff clayey soil, and dense sandy silt. The region is experiencing an ongoing land subsidence affecting the upper about 40 m of soil and, on average in the city, the ground surface is currently settling 16 mm/year. The test records were processed by means of effective stress analysis to provide the axial pile force distribution, load transfer functions, and equivalent head-down load–movement curve. The analysis was then used to obtain the equivalent pile-head load–movement response adjusted to the planned 22 m deep basement excavation. Load transfer functions were back-calculated from the test records and indicate that the construction will show somewhat large load-transfer movement. However, because the equilibrium plane will be below the subsiding layers, below 40 m depth, downdrag is not expected to affect the building. The load response of the barrettes is compared to the results of a bidirectional (BD) loading test on a 1.8 m diameter bored pile at an adjacent project.

中文翻译：

---

发夹桩双向静载试验。越南胡志明市的病史

加拿大岩土工程杂志，印刷前。
在越南胡志明市 72 m 深处安装的两个应变仪仪表发夹上进行了双向静态载荷测试。这些发夹用于支撑一栋 16 层、有 5 个地下室的建筑。土壤剖面由中粗至细砂、中粘土、坚硬至坚硬粘土和致密砂质粉土层组成。该地区正在经历持续的地面沉降，影响到上部约 40 m 的土壤，目前该市地表平均每年沉降 16 毫米。测试记录通过有效应力分析进行处理，提供轴向桩力分布、载荷传递函数和等效头朝下载荷-移动曲线。然后使用该分析来获得根据计划的 22 m 深地下室开挖调整的等效桩头荷载-移动响应。荷载传递函数是根据测试记录反算的，表明该结构将显示出较大的荷载传递运动。然而，由于平衡面将位于沉降层下方，深度低于 40 m，因此预计下阻力不会影响建筑物。将发夹的载荷响应与相邻项目中 1.8 m 直径钻孔桩的双向 (BD) 载荷测试结果进行比较。