木质纤维与水泥共同改良软土的力学性能与微观机制分析

通过压实试验、无侧限抗压强度试验和劈裂试验,分析不同木质纤维含量、水泥含量和固化时间对软土力学性能的影响规律,探讨木质纤维、水泥改良软土的微观机制。结果表明,木质纤维的加入对水泥改良软土的击实特性有显著的影响;木质纤维与水泥可有效改善土体的抗压和劈裂抗拉强度,随着木质纤维含量的增加,改良土的抗压和劈裂抗拉强度呈现出明显的“驼峰”现象,并在木质纤维含量为0.25%时最大;木质纤维与水化产物、软土颗粒形成互锁效应,增大了改良土的摩擦力,同时木质纤维还承担一定的拉伸强度,使改良土的劈裂强度增加。

Analyses on the Mechanical Properties and Micro Mechanism of Soft Soil Improved by Wood Fiber and Cement

Through compaction test,unconfined compressive strength test and splitting test,the influences of different wood fiber content,cement content and curing time on the mechanical properties of soft soil are analyzed,and the micro-mechanism of soft soil modified by wood fiber and cement is studied.The results show that,(a)the addition of wood fiber has a significant influence on the compaction characteristics of the cement-modified soft soil;(b)the wood fiber and cement can effectively improve soil compressive and splitting tensile strength,and with the increase of wood fiber content,the compressive and splitting tensile strength of modified soil presents an obvious"Hump"phenomenon with a maximum when the content of wood fiber is 0.25%;and(c)the interlocking effect of wood fiber with hydration products and soft soil particles increases the friction of modified soil,and meanwhile,the wood fiber also assumes certain tensile strength,which increases the splitting strength of modified soil.