Matrix suction effect on the soil stability in unsaturated soil

In recent years, high-rise buildings have widely increased in cities, and there is an increasing need to excavate deep tranche to use the available space efficiently. One of the ways to stabilize the tranche is to use metal piles and an anchorage system. In many cases, tranche failure is due to rains, the explosion of water pipes, absorbing wells, and artesian layers. Due to these factors, matrix suction decreases, and pore water pressure increases. As a result, parameters of the shear strength of the soil weaken, and instability occurs. In the present research, using numerical simulation through SEEP/W and Slope/W software and considering two types of soil, i.e., sand and clay, the effect of water pipe explosion, the existence of an absorbing well and artesian layer is examined on the stability of a tranche stabilized by anchorage and metal pile over time. Also, the effect of the change in water pipe position, absorbing well, and the artesian layer is studied on the tranche's safety factor. The results show that as the water pipe's distance and absorbing well increases from the failure zone, the safety factor increases. Also, as the artesian layer's distance increases from the tranche floor, the safety factor increases.