三向应力下膨胀土含水量与膨胀率关系研究

膨胀土具有吸水膨胀的工程特性,因而通常采用的有侧限膨胀试验具有一定局限性。采用应变控制式三轴仪来实现对膨胀土试样压力的连续施加,使土样在合理的受力和吸水环境下,膨胀变形至剪切破坏;并根据相关物理性质指标转换公式,得到试样在连续性吸水过程中不同含水量与体积膨胀率的关系。改进后的三轴膨胀试验合理地模拟了膨胀土在一定埋深条件下其吸水膨胀的真实过程,科学地解决了分阶段有侧限膨胀试验不能实现同一试样吸水膨胀的连续性过程问题,试验结果更为准确,使得室内试验环境和工程实际达到较好吻合,对于研究膨胀土的力学行为具有一定的合理性和科学性。

Study on the Relationship between Water Content and Expansion Ratio of Expansive Soil under Three Dimensional Stress State

The expansive soil has a engineering property of water swelling,however,there are some limitations in the lateral constrained expansion experiment generally used. Triaxial apparatus of strain controlled is used to implement successive pressure on the swelling soil sample, thus the sample deforms until shear failure under reasonable force and water absorption environment. The relationship between different water content and volume expansion ratio in the process of continuous water absorption is acquired based on the related convert formulas of physical indicators. The modified triaxial swelling test reasonably simulates the real processes of expansive soil expand with water absorption under certain buried depth. The test scientifically solves the problem that lateral constrained expansion experiment cannot achieve the continuous process of the same sample expand with water absorption. The test results are more accurate and it reach a better match between laboratory experiment and engineering practice. The results have certain rationality and scientificity for the study on the mechanical behavior of expansive soil.