冻结泥炭质土力学性质试验研究-《高速铁路技术》

文章信息/Info

Author(s):: FENG Ziliang; China Railway Eryuan Engineering Group Co., Ltd., Chengdu 610031, China

摘要:: 冻土受温度影响强烈，且在温度变化过程中常伴有冻融循环，对我国寒区工程造成了极大的损害。针对这一情况，本文在-6℃的温度下对冻结泥炭质土进行了单轴压缩试验和围压范围为1~6 MPa的三轴压缩试验，试验结果表明：（1）低围压和高围压下围压对冻结泥炭质土应力-应变曲线影响明显，而中等围压下围压对冻结泥炭质土应力-应变曲线的影响较小；（2）低围压、中等围压和高围压下围压对冻结泥炭质土强度的影响机制不同，冻结泥炭质土强度随围压的变化规律可分为3个阶段，分别对应于围压的3个阶段，即低围压下强度快速增长阶段、中等围压下强度缓慢增长阶段和高围压下强度降低阶段。结论可为相似地质条件下工程设计提供依据。

Abstract:: Frozen soil is strongly affected by temperature, and it is often accompanied with freeze-thaw cycles when temperature changes, which causes great damage to the projects in cold regions of China. In view of the above situation, uniaxial compression test and triaxial compression test with confining pressure range of 1~6 MPa are carried out for frozen peat soil at a temperature of -6℃ in the paper. The test results shows that:(1) Both low confining pressure and high confining pressure have a significant effect on the stress-strain curve of frozen peat soil, while the medium confining pressure has a smaller effect on it. (2) The influence mechanism of low, medium and high confining pressure on frozen peat soil strength is different. The change law of frozen peat soil strength can be divided into three stages, which correspond respectively to the three stages of confining pressure, namely, the rapid increase stage of strength under low confining pressure, the slow increase stage of strength under medium confining pressure and the decrease stage of strength under high confining pressure. The results could provide basis for the engineering designs under the similar geological conditions.