用十字板强度推算软黏土抗剪强度指标的方法及应用

天津港区地基土上覆较厚的软黏土层,处于欠固结状态,含水率高,承载力低。在构筑物施工期稳定性分析中,需要采用不排水强度指标。常用的几种抗剪强度指标中,以十字板强度最为可靠。但由于十字板强度是土体各滑动面上的抗剪强度的较小值,用于计算土坡稳定性计算常得出过于保守的不合理的结果。同时,单一的十字板强度指标无法用于计算箱筒型基础的地基土压力及承载力。基于十字板强度随深度线性分布的规律及莫尔–库仑抗剪强度原理,结合收集的大量的十字板强度实测数据,通过回归统计分析推算出地基土的两个抗剪强度指标,并将其应用于软黏土土坡的稳定分析及新型箱筒型基础稳定性的计算,计算结果较为合理。 AbstractFilter('ChDivSummary','ChDivSummaryMore','ChDivSummaryReset');

Deduction and application of strength parameters of soft clay by use of vane strength

In Tianjin Port,the foundation soils are soft clay with underconsolidated condition,low bearing capacity and high water content.The vane strength is more frequently used among the currently used strength parameters in assessing the stability analysis of the structure during the construction stage.Research results have shown that the vane strength is smaller than compared with the strength on other shear surfaces.Furthermore,a single value of the vane strength can not meet the requirements for calculating the earth pressure and bearing capacity.A new approach which can deduce the two conventional strength parameters based on the linear distribution of vane strength along the depth and the Mohr-Coulomb strength mechanism is presented by use of the statistical regression methods.The deduced parameters have been used to calculate the stability of slopes and the cylindrical caisson foundations in Tianjin Port.