岩石含水状态对岩石膨胀力影响的研究

岩石膨胀力试验是测定膨胀岩在水环境下所产生膨胀应力的试验方法。岩石的含水状态对膨胀力测试值具有重要影响。本文通过对岩石试样进行不同含水状态的膨胀力试验,研究了含水状态对岩石膨胀力试验结果的影响程度和规律。结果表明:含水状态对膨胀力测试值的影响显著,风干状态下的膨胀力平均值是饱和状态的83.0倍,烘干状态下的膨胀力平均值是饱和状态的77.6倍,烘干或风干状态的岩石再次遇水后,会出现持续膨胀的趋势,长期干燥环境使岩石内部毛细水充分排出,当岩石再次吸水膨胀时其更具危害性。对于材质均匀,一致性较好的膨胀岩,膨胀力测试值随含水比的增大而减小,随空孔率的增大而增大,且相关性较好。

A Study on Influence of Rock Moisture Condition on Rock Swelling Force

Rock swelling force test is a test method to determine the swelling stress produced by swelling rock in the water.The moisture condition of rock has an important influence on the measured value of swelling force.This paper studies the influence degree and law of moisture conditions on the test results of rock swelling force through the swelling force tests of rock samples under different moisture conditions.The results show that the moisture condition has a significant influence on the test value of swelling force.The average swelling force in air-dried state is 83.0 times that in a saturated state and 77.6 times that in a drying state.After the rocks in drying or air-dried state meet with water again,there will be a tendency of continuous swelling.The long-term dry environment makes the capillary water in the rocks fully discharged,which is more harmful when the rocks absorb water and swell again.For swelling rock with uniform material and good consistency,the measured value of swelling force decreases with the increase of water content ratio and increases with the increase of porosity,and the correlation is good.