降低上海软粘土变形效应的加筋试验研究

An Experimental Study of the Effects of Palm and Wheat Straw Reinforcement on Reducing the Deformation of Soft Clay in the Shanghai Area

为改良上海粘土的强度和变形特性，分别采用棕榈和麦秸秆加筋，以提高土的强度和抗变形性能。试验以质量加筋率和加筋长度作为影响因素，分析比较两种加筋土的无侧限抗压强度。试验结果为：（1）棕榈加筋土的无侧限抗压强度高于麦秸秆加筋土，两种加筋土均高于素土。（2）棕榈的适宜加筋条件为：质量加筋率1．0％，加筋长度的平均值15mm；四分之一圆管状麦秸秆的适宜加筋条件为：质量加筋率0．3％～0．4％，加筋长度15mm。（3）棕榈加筋土的应力应变曲线表现为应变强化型，麦秸秆加筋土的应力应变曲线表现为应变软化型。初步试验结果表明，棕榈与麦秸秆均适宜作上海地区粘土的加筋材料，加筋效果棕榈优于麦秸秆。

To improve the strength and deformation characteristics of Shanghai cohesive soil, both palm and wheat straw were added to the soil. The unconfined compressive strength （UCS） of the soils reinforced with palm and wheat straw was analyzed by selecting different reinforcement lengths and reinforcement quality ratios as influencing factors. The analyses yielded the following results. （1） The UCS of palm-reinforced soil is higher than that of wheat-straw-reinforced soil, and both composite mixtures are stronger than the original soil. （2） The optimal reinforcement length of palm is approximately 15 mm and the optimal reinforcement ratio is about 1.0% of total weight. The optimal reinforcement length of wheat straw is approximately 15 mm and the optimal reinforcement ratio is about 0.3%-0.4% of total weight. （3）The stress-strain curve of palm-reinforced soil is found to be a strain-hardening type, whereas the stress-strain curve of wheat-straw-reinforced soil is a strain-softening type. Preliminary results show that both palm and wheat straw are optimal for use as a reinforcement material and that the reinforcement effect of palm is better than that of wheat straw.