厦门市海积淤泥水泥土力学性能试验研究

Experimental Study on Mechanical Properties of Cemented Marine Silt in Xiamen

为探索厦门市海积淤泥水泥土工程特性,根据土体物理力学性质指标制定了水泥土配比方案,采用无侧限抗压试验与直剪试验获得了水泥土力学参数,分析了含水率、龄期与水泥掺入比对水泥土力学特性的影响。结果表明:当海积淤泥初始含水率为45%~65%、水泥掺入比为9%~21%时,水泥土无侧限抗压强度为0.46~5.38 MPa,内摩擦角为13.61°~41.99°,黏聚力为65.8~787.25 kPa;含水率55%是水泥掺入比对水泥土强度影响程度的分界线;当水泥掺入比低于18%时,水泥土的抗压强度与黏聚力近似呈线性增大,且初始土体含水率45%的水泥土强度增长速率大于含水率55%与65%;当水泥掺入比大于18%时,强度指标增长速率降低。在试验结果基础上,提出了一种适用于厦门市海积淤泥水泥土的无侧限抗压强度预测公式。

In order to explore the engineering characteristics of marine silt cement-soil in Xiamen, the mixed proportion of tests of cement-soil is formulated according to the physical and mechanical property indexes of soil. The mechanical parameters of cement-soil were obtained by unconfined compression test and direct shear test, and the influence of water content, age of cement-soil and cement content on the mechanical properties of cement-soil was analyzed. The results show that when the initial water content of marine silt is 45%~65% and the cement content is 9%~21%, the unconfined compressive strength of cement-soil is 0.46~5.38 MPa, the internal friction angle is 13.61°~41.99°, and the cohesion is 65.8~787.25 kPa, the water content of 55% is the dividing line of the influence of cement content on the strength of cement-soil. When the cement content is lower than 18%, the compressive strength and cohesion of cement-soil increase approximately linearly, and the strength growth rate of cement-soil with initial soil water content of 45% is greater than that of 55% and 65%;When the cement content is greater than 18%, the growth rate of strength index decreases. On the basis of the test results, an unconfined compressive strength prediction formula suitable for Marine silt cement soil in Xiamen is put forward.