不同埋深粉细砂层旁压承载特性试验研究

Experimental Study on the Bearing Characteristics of the Foundation in Different Buried Depth of Silty Sand

采用室内土工试验与现场原位试验相结合的方式,对不同埋深粉砂细层的旁压承载特性指标变化规律进行了对比分析,结果表明:(1)旁压曲线呈典型的“初始-稳态-加速”三阶段变化特征;(2)随着上覆压力(深度)的不断增加,旁压模量逐渐增大,并呈良好的对数关系;相同上覆压力下,砂土层的密度越大,旁压模量越大,且在不同上覆压力下均呈相似变化特征;(3)相比标贯试验和固结试验,现场旁压试验得到的压缩模量偏大,提出采用对数修正公式进行修正,修正后的压缩模量与工程实际较为吻合。相关理论和方法可为旁压试验在深层土层中的勘探应用提供借鉴。

Based on the combination of indoor geotechnical test and field in-situ test,this paper makes a comparative analysis on the variation law of pressured load-carrying characteristics indexes of different buried silty sand fine layers.The results show that:(1)the pressured curve shows a typical three-stage change characteristic of"initial steady acceleration";(2)with the increase of overburden pressure(depth),the pressured modulus increases gradually and presents a good logarithmic relationship;under the same overburden pressure,the higher the density of the sand layer,the greater the modulus of lateral compression,and it shows similar characteristics under different overburden pressures;(3)compared with the standard penetration test and consolidation test,the modulus of compressibility obtained from the field pressured by the sand layer is too large,and the modified formula is proposed to be modified,and the modified modulus of compressibility is more consistent with the actual engineering.The relevant theories and methods can provide reference for the exploration and application of pressuremeter test in deep soil layer.