深中通道深层水泥搅拌法水泥土强度特性室内试验研究

Laboratory test for strength properties of cement soil with DCM in Shenzhen—Zhongshan linking

依托深中通道深层水泥搅拌法(DCM)地基处理项目,对工程区域海相软土层开展室内配合比试验研究,分析土层性质、水泥掺量、龄期、水泥土含水率、水泥土密度等因素对水泥土强度特性的影响。试验结果表明,工程区域海相软土层水泥固化处理效果显著,56 d龄期水泥土强度达到2.0 MPa以上,DCM处理时水泥掺量宜高于260 kg/m^3;水泥土的含水率、密度在水化反应过程中基本保持不变,主要取决于原状土物理性质,并导致水泥土强度差异。根据试验结果,建立各层土的水泥土强度预测公式,并通过工程现场南侧水泥土强度实测值与预测值的对比,验证强度预测公式的有效性。

Based on the project of Shenzhen—Zhongshan linking with deep cement mixing method( DCM)foundation treatment,we carry out the indoor mix ratio test of the marine soft soil layer,and analyze the effects on the strength characteristics of cement soil,including the soil layer properties,cement content,age,cement soil moisture content,as well as the cement soil density.The test results show that the cement hardening effect of the marine soft soil layer in the engineering area is significant. The strength of cement soil in 56-day age is above 2. 0 MPa, and the cement content suggested would be higher than 260 kg/m^3 in DCM treatment. The moisture content and density of cement soil basically remain unchanged during the hydration reaction, which mainly depends on the physical properties of the undisturbed soil and causes the cement soil strength difference. Furthermore, based on the test results,we establish a cement soil strength prediction formula for each layer of soil,and verify the validity of the strength prediction formula by comparing the measured and predicted strengths of the cement soil strength on the south side of the project site.