新疆叶尔羌河某水电站深厚砂卵砾石层坝基承载力及变形特性原位试验研究

In Situ Experimental Study on the Bearing Capacity and Deformation Characteristics of the Deep Sand Gravel Layer Dam Foundation of a Hydropower Station in the Yerqiang River, Xinjiang

针对新疆叶尔羌河某水电站深厚砂卵砾石覆盖层坝基,采用刚性承压板法开展原位承载力及变形试验研究,采用直径为50 cm和75 cm的承压板分别开展试验,试验结果表明:冲积形成的深厚密实砂卵砾石层具有相当高的承载能力,加载至3 MPa以上仍未出现较明显的破坏现象,且比例界限并不明显,判断其承载力特征值需要结合试验曲线及沉降与承压板直径之比即S/d值进行选取。采用不同直径的承压板试验所得到的加载曲线未表现出明显不同,获得的变形模量在同一水平,表明在一定尺度范围内承压板直径对试验结果影响不大。

A rigid pressure plate method was used to conduct in-situ bearing capacity and deformation tests on the dam foundation of a hydropower station in the Yerqiang River, Xinjiang for a deep and dense sand and gravel covering layer. The tests were conducted using pressure plates with diameters of 50 cm and 75 cm, respectively. The test results showed that the deep and dense sand and gravel layer formed by sedimentation has a relatively high bearing capacity, and no obvious failure characteristics were observed when loaded above 3 MPa, and the proportion limit is not obvious. To determine the characteristic value of its bearing capacity, it is necessary to combine the test curve and S/d value, and consider engineering design for selection. The loading curves obtained from the test using pressure plates with different diameters did not show significant differences, and the deformation modulus obtained was at the same level, indicating that the diameter of the pressure plate has little effect on the test results within a certain scale range.