木质素纤维红黏土强度及变形特性试验研究

利用工业废料改良土体性能不仅具有实用价值而且能够保护环境。采用室内土工试验及SEM试验，针对木质素纤维加筋红黏土的效果，以及木质素纤维掺量对红黏土强度及变形特性的影响规律和作用机理进行研究。试验结果表明:木质素红粘土压缩模量随着纤维掺量的增加先增加后减小，2%纤维掺量时，模量最高；不同木质素掺量红粘土的内摩擦角基本保持不变；红黏土黏聚力随木质素掺量的增加先减小后增大再减小。2%是纤维最优掺量，土体黏聚力出现最大值；在三轴实验中，加筋红黏土试样均发生鼓胀变形，没有明显的破裂面，具有典型的应变硬化特征。研究结果表明木质素纤维能一定程度提高红粘土的强度，提升红粘土的工程应用价值。 

EXPERIMENTAL STUDY ON THE SHEAR STRENGTH AND DEFORMATION CHARACTERISTICS OF LIGNIN-FIBER RED CLAY

The pollution of geomaterials is one of the key problems in construction. Considering proportion of lignin fibre, laboratory mechanics experiments and SEM tests were applied to natural red clay and lignin fibre-adding red clay. Variation laws of strength characteristics and effects were studied when added volumes were various. The results showed that:lignin fibre could enhance the compression modulus of red clay under different press levels and the results appeared regularly changing; cohesive strength of red clay increased first then decrease with the increase of lignin fibre. Interlock forces that formed between lignin fibre and soil particle were less than joint force existing in skeletal structure of natural red clay, which could not enhance the soil strength when mixing amount was under 1%. Cohesive strength showed maximum, but the internal friction angle remained stable when the mixing amount was 2%; stressed red clay containing lignin fibre showed bulging deformation without obvious fracture surface. Hence, tension failure and adhering failure didn''t exist in red clay containing lignin fibre and presented typical properties of strain hardening; red clay containing lignin fibre could enhance the residual strength effectively.