加筋黏性土加筋效果的三轴试验研究

Triaxial Test Study on Reinforcement Effect ofReinforced Cohesive Soil

为研究施工期加筋黏性土的加筋效果,考虑加筋构筑物施工速度快、排水条件差等不利条件,选用各向同性的铝箔做加筋材料,采用三轴试验研究施工期加筋黏性土强度及变形破坏特性。试验结果表明:加筋黏性土的应力-应变特性曲线呈应变软化型,试样均表现为拉断破坏;相同轴向应变时,围压越大,轴差应力越大;围压一定时,加筋层数越多,加筋效果越好;高围压下需达到一定轴向应变,筋材即发挥作用,围压越大滞后效应越明显;黏性土中加筋作用表现为土体黏聚强度的增加,说明准黏聚力理论可用于分析评价施工期加筋黏性土的加筋效果。

In order to study the reinforcement effect of reinforced cohesive soil in construction period,considering the disadvantages such as fast construction speed and poor drainage conditions of reinforced structures,the isotropic aluminum foil was selected as reinforcement material,and triaxial test was used to study the strength and deformation failure characteristics of reinforced cohesive soil in construction period.The test results show that the stress-strain characteristic curve of reinforced cohesive soil is strain softening type,and the specimens are tensile failure.Under the same axial strain,the greater the confining pressure is,the greater the axial differential stress is.Under the given confining pressure,the more layers of reinforcement,the better reinforcement effect.Under high confining pressure,when a certain axial strain is reached,the reinforcement will play a role;the higher the confining pressure is,the more obvious the hysteresis effect is.The reinforcement effect in cohesive soil is shown by the increase of cohesive strength of soil,which indicates that the quasi-cohesion theory can be used to analyze and evaluate the reinforcement effect of reinforced cohesive soil during construction.