Abstract: In view of the problems such as the insufficient bearing capacity of foundation and the failure of slope on the soft soil foundation, the stress-strain characteristics, deformation laws, strength characteristics and failure forms of the cement soil were analyzed and studied by carrying out triaxial CD tests with different cement content and confining pressure in the laboratory. The test results show that: under the same confining pressure, with the increase of cement content, the shear strength of cement soil shows a nearly linear growth relationship; with the increase of confining pressure, the strain, shear strength and residual strength after failure of cement soil increase gradually; with the increase of cement content, the volume strain of cement soil increases first and then decreases, which has dilatancy characteristics and finally tends to a certain stable value. The failure mode of cement soil is related to cement content and confining pressure, which mainly presents as three failure modes, such as plastic shear failure (low ac/high po), brittle fracture failure (high ac/low po) and oblique shear failure {(low/high ac, high/low po)}.

Key words: geotechnical engineering, cement soil, CD test, cement content, shear strength, volume strain

摘要： 针对软弱土地基上建造构筑物易出现地基承载力不足、边坡失稳破坏等问题，通过对室内开展不同水泥掺量、不同围压下三轴CD试验，分析研究了水泥土的应力-应变特征、变形规律、强度特性和破坏形式。试验结果表明：同一围压下随水泥掺量的增加，水泥土的抗剪强度呈现近线性增长关系；随着围压的增加，水泥土破坏时的应变、抗剪强度及破坏后的残余强度呈现逐渐增大趋势；随水泥掺量的增大，水泥土体积应变呈现先增后减小趋势，具有剪胀特性，最终会趋于某一稳定值；水泥土的破坏模式与水泥掺量和围压有关，主要表现为塑性剪切破坏(低ac/高po)、脆性劈裂破坏(高ac/低po)和斜向剪切破坏{(低/高ac、高/低po)之间}3种破坏模式。

关键词: 岩土工程 , 水泥土, CD试验, 水泥掺量, 抗剪强度, 体积应变