Application Of Critical Slip Field Theory In Earth Pressure Calculation Of Retaining Wall

Critical slip field method has successfully solved the problem of the calculation of slope stability,but the calculation and research of earth pressure under seismic load as well as broken line retaining wall are not involved. This article is the promotion and development of critical slip field method to study the calculation of earth pressure under seismic load as well as broken line retaining wall. Contents and conclusions are as follows:The earth pressure of retaining wall, which is influenced by ratios between upper and lower wall height as well as their wall corner, is discussed. what's more, by means of studying many factors which influence the seismic earth pressure, some valuable conclusions on engineering are obtained.Considering the broken line retaining wall, optimization of the height ratio between the upper and lower wall should consider the size of active earth pressure on retaining walls and its corresponding overturning safety factor. According to the calculating results of the example in this article, the appropriate optimal ratio should be around 1.Considering other factors, in order to reduce the upper and lower wall earth pressure we can reduce the corner of upper wall as much as possible and increase the lower wall corner correspondingly.Thereby we can reduce the constructing cost of the retaining wall.As regard the earth pressure under seismic load, the method of calculation of seismic earth pressure basing on the critical slip field theory have utilized the basic assumptions of Monobe Okabe method.What is more, it overcomes the deficiency of the Monobe Okabe method. (not involving the impact of cohesion),meanwhile the calculating result approximates the result of the Monobe Okabe method. we can calculate by considering various factors affecting seismic earth pressure. The horizontal seismic coefficient has a major impact on the seismic earth pressure rather than the vertical seismic coefficient, meanwhile, with the increasing of the vertical seismic coefficient, the seismic earth pressure reduce correspondingly.Some criterions ignore the impact of vertical seismic load, the result is safer. When the earth internal friction angle or soil cohesion increases,the seismic earth pressure decreases correspondingly.Considering these, we should choose the soil with big internal friction angle while selecting the type of filling behind the retaining wall.