Experimental study on SWCC of expansive soil with cracks using filter paper method

To overcome the shortage of traditional suction test methods,the filter paper method was applied to measure the matric suction of expansive soil with cracks and the corresponding soil water characteristic curve(SWCC) was obtained.The characteristics of expansive soil with cracks are found to be similar with the characteristics of the soil without cracks.The SWCC is composed of three parts and is shown as an inverted ‘S'shape.Under the same water content conditions,the matric suction of expansive soil under the conditions of drying is greater than that under the condition of wetting.The drying and wetting curves form a hysteretic loop and a hysteretic phenomenon is clearly shown.The test results can be fitted and analyzed by existing calculation models of SWCC.It is revealed that the filter paper method can be used to obtain the soil suction under any status avoiding the interference to the soil original status.It is an effective method to measure the suction capacity of expansive soil with cracks and other special soils.