针刺GCL内部剪切强度的试验研究

Experimental Research on Internal Shear Strength of Needle-punched GCL

摘要:

通过室内直剪试验研究了土工合成材料膨润土垫（GCL）内部剪切强度及其影响因素，为满足本文研究的要求，对直剪仪进行了改造。研究结果表明：针刺GCL的内部剪切强度主要受针刺纤维的抗拉和缠绕作用控制，其他因素对GCL内部剪切强度贡献很小；正应力和水化液类型对GCL内部剪切强度均有影响，表现为内部剪切强度随着正应力的增大而逐渐增大，水化液为蒸馏水时GCL的内部剪切强度最大；在实际工程应用中，GCL铺设完成后在堆载之前应采用自来水进行事先水化，可提高防渗工程的稳定性。

Abstract:

The paper presents a research on the internal shear strength of a type of needle-punched GCL and the influencing factors on the basis of the laboratory direct shear test, the direct shear apparatus is modified to meet the research requirements. Experimental results show that: the internal shear strength of GCL is controlled by the needle-punched fiber, other elements have minor influence on the internal shear strength; normal stress and hydration liquid both have impacts on GCL’s internal shear strength. Shear strength increases with the increasing of normal stress, and the strength reaches the largest value when GCL is hydrated by de-ioned, distilled water; in practice, GCLs should be pre-hydrated with tap water before being loaded, this measure can increase the stability of barrier systems.