The construction of basement in urban areas e.g. metro railway or building consisting of many basement levels often involves excavation with vertical walls that are usually supported with internal struts. Although Rankine and coulomb earth pressure theories are used to design these members Corresponding to researches carried out in recent fifty years, measured loads of struts are not only induced by earth pressure, but are due to ambient air temperature increasing as well. Without appropriate consideration of thermal effects, measured loads may be misinterpreted solely as loads from the retained earth or design loads based only on computer analyses may not be representative of potential loading conditions. This study predicts thermal load induced in the struts due to temperature variation by thermal analyses. Numerical program used in this study is finite difference code, FLAC3D, using elastic–perfectly plastic Mohr-Coulomb model for sandy soils and Cam-Clay model for clay. Soil behavior was modeled by constitutive relations developed by Maleki et al. as well and results are compared with Mohr-Coulomb and Cam-Clay models. Some features such as strut stiffness, depth of excavation, distance between piles, and depth of embedment of pile below excavation bottom are studied and lateral earth pressure diagrams are presented. Keywords: lateral earth pressure, braced excavation, struts
