ساجده همتي

Uncertainty is a fundamental and very important principle in geotechnical engineering. Uncertainty on a large scale leads to proximity and the occurrence of a critical state. The geotechnical engineer tries to take this uncertainty into account by wisely choosing conservative parameters to eva‎luate contractual stability. Calculating the bearing capacity of foundation is a geotechnical engineering problem characterised by many sources of uncertainty. One of the uncertainties is related to voids in the lower layers of soil, which have two major reasons for such voids in the soil layer: 1) human activities such as tunneling, mining and excavation in the ground, 2) dissolution Soluble materials (salt, dolomite, etc.). In many projects their location, size and shape are not exactly known. Physical description of the position of voids is difficult due to the high cost of experiments and the uncertainty of measurement errors. As a result, information about these voids is associated with uncertainties that lead to probabilistic methods for their analysis. In this study, the effect of random soil voids placed in one layer on the problem of bearing capacity of surface foundations on homogeneous clay is investigated by combining the numerical method of finite difference and the theory of random fields in the Monte Carlo simulation framework. In this study, the finite difference technique in FLAC2D software is used. For the effect of random voids, many samples of random fields were generated for different data sets, including the probable layer thickness, distance from the surface, the size of the voids and center position of the voids, and for each of them, numerical analysis was performed. Analyzes are performed for two different shapes of voids in the form of circles and squares. According to the results, there is a critical area in terms of the distance of the cavity layer from the foundation and the exit from the center of the foundation to the cavity, which affects the stability and bearing capacity if the cavity is located in this area. According to the results, there is a critical area in terms of the distance between the layer of the void from the foundation and the eccentricity of the foundation to the cavity, which if the cavity is located in this area, affects the stability and bearing capacity and increasing these distances reduces the probability of failure. The study showed that in some cases the Bearing capacity coefficient was reduced by up to 40%.

ظرفيت باربري , عدم قطعيت , حفرات تصادفي , مونت‌كارلو , پي نواري سطحي

Bearing capacity , Uncertainty , Random voids , Monte Carlo , Surface strip foundation

sajedeh hemmati

Mehran karimpour-fard & Habib Shahnazari