加筋长度和加筋率下的稻草加筋土强度特征

Strength and deformation of saline soil reinforced with rice straw

为了解决由盐胀和溶陷导致的盐渍土低强度和大变形问题,依据抗压实验和三轴压缩实验,研究6种加筋长度和5种加筋率下的稻草加筋滨海盐渍土的抗压强度、抗剪强度和抗变形性能。结果表明,直径50mm抗压试样的适宜加筋率为0.2%,适宜加筋长度为15mm,直径61.8mm三轴压缩试样的适宜加筋率为0.2%,适宜加筋长度为20mm,这2种条件下加筋土的强度值最高、抗变形性能最优。加筋大幅提高了土的黏聚力,但对土的内摩擦角影响很小,只有在加筋土达到一定的轴向应变时,稻草的加筋作用才能发挥出来。

Such problems of saline soil,as inferior strength and more deformation which result from crystal- lizing and dissolving of the salt in soil can be treated by reinforcing the anti-decayed rice straw by means of unconfined compressive test and triaxial shear test on the saline soil reinforced with the rice straw under the condition of six reinforcing length and five reinforcing rate. The results indicate that the suitable rein- forced condition on the sample in diameter of 50 mm is of the reinforcing length of 15 mm and of reinforcing rate of 0.2 ~ for unconfined compressive test, and the reinforcing length and the reinforcing rate of 20 mm and 0. 2~ is suitable reinforced condition on triaxial shear sample in diameter of 61.8 ram, with the best reinforcement effects. The reinforcement increases mainly the cohesion and exerts little influence on the in- ternal friction angle. The rice straw decreases evidently the lateral deformation of the reinforced saline soil only when the sample going a certain axial strain. The results give the guidance for studying the strength and deformation of the reinforced saline soil at some reinforcing condition and some size of sample.