Calculation And Forming Of Earth Pressure Against Underground Parking Garage

Nowadays, in order to save land, underground projects gradually increase. Moreover, with popularizations of the car, parking become a big problem, therefore underground parking turns into a focus, the construction of underground parking garage has got recognition unprecedented. In design of the underground parking garage, the sidewall is a very important part, the value of load on the wall—earth pressure is the most important question for the sidewall design. At present, the calculation of earth pressure on the sidewall of underground parking garage is still in the original stage, for convenience and absolutely safe, mostly the static earth pressure is choosed.According to 《Code for design of concrete structures》 , the permissible distortion of basement wall is very small compared with the retaining wall, therefore the soil distortion belongs to the small strain. In the designs of underground parking garage and other underground projects, although abnormity has already been discovered in the small strain of soil long before, it hasn't been attached importance to, to this day, the soil's constitutive model and the distribution of earth pressure under small strain have not got deeply researched. This paper takes the earth pressure on sidewall of underground parking garage as the research object, through building a planar model of underground parking garage with different height, rigidity, and soil by the Finite Element Method, analyses the magnitude and the change of earth pressure, finds the difference between it and classic earth pressure.First, 4m and 6m high wall are choosed, and the distributing of earth pressure on the two different high wall is analyzed. Soil arching effect of earth pressure is evidenct when the soil behind 4m high wall is sand, but displacement is very small, which different from the common point that soil arching effect should be along with big displacement. Subsequently, through analyzing the soil character behind sidewall influence on the distributing of earth pressure, the friction angle is the most important diathesis to influence soil arching effect of earth pressure, and the friction angle's influence is allowed to neglect.