ارزیابی پایداری ساختمان خاک به روش منحنی رطوبتی پرانرژی

Climatic factors have a great impact on soil transformation and soil structure. Climate affects the processes of soil formation and soil structure and maintaining moisture in the soil through factors such as rainfall, temperature, evaporation and transpiration, dry and wetting cycles. In order to evaluate the stability of the soil structure and the factors affecting the stability of the soil structure, using the high-energy moisture characteristic curve method was used. For this purpose, in a trial based on a randomized complete block design in the Split-Plot design replicated in time, the effect of three different types of tillage management (conventional tillage, low tillage and no tillage) on the high energy moisture characteristic (HEMC) was occurred. The HEMC data were modelled using the modified van Genuchten model. The values of stability index (SI) were determined for slow-wetted and fast-wetted samples. Moreover, the ratio of volumes of drainable pores (VDPR) and the ratio of matric suctions at inflection point of HEMC (MS) were calculated as the relative indices of soil structure stability. The results of the high-energy moisture curve showed that the pore destruction in slow wetting is less than that of fast wetting.The results showed that with the increase of tillage operations, the values of soil structure stability index (SI) decrease, especially in the fast method. Rapid wetting by reducing the size of soil pores causes an increase in MS and also a decrease in VDP, as a result of which the value of SI decreases.