Design Method Of Piled Retaining Wall For Dk61+075～+351Slope Along The Railway From Bazhong To Dazhou In China

With the development of highway and railway, stabilizing piles have been more and more frequently used for slope stability. In recent years, some other retaining structures are used between piles for between-pile soil stability and weathering prevention of rocks. Piled retaining wall is a very popular example. However, a problem is so far exsiting that the theoretical research of the structure is fallen far behind the practice. There are two reasons can be identified to account for this problem. Firstly and foremost, the design method of the structure is not very reasonable. Secondly, the distribution of loading between pile and retaining wall is not clear. Therefore, a theoretical research about design method of piled retaining wall is carried out, in which soil arch effect is accounted for the calculation of the loading on the retaining wall. And DK61+075～+351slope along the railway from Bazhong to Dazhou in China is taken as an example to demonstrate the desigh method presented in this paper.(1) The engineering geological conditions of the example slope are analyzed. Basing on the analysis, the slope is calculated with the use of transfer cofficient method and the factor of safety (FS), as well as the driving force, is obtained. The result shows that the slope is unstable after excavation and some reinforcements are necessarily needed to keep the slope stable.(2) According to the codes for stabilizing pile, calculations show that the piles for the example slope should be designed to be cantilever elastic piles.(3) The earth pressure applying on the retaining wall between the piles are calculated with the consideration of soil arch effect, basing on which the retaining wall is designed. The dip angle of the failure plane is firstly found by the use of Rankin theory in active state. The boundary of the soil arch is then determined as a isosceles triangle according to a code for slope design.(4) Numerical simulation is carried out as an optional mehtod to tell whether the design of the retaining structure is correct and effective. The analysis of slope stability befor and after the construction of the pile-wall combination is completed. The results show that the design method is effective.Theoretical significance and practical applicational meaning are there in the results of the study. The results can be used to design the retaining structures for the slopes along the railway from Bazhong to Dazhou with the similar geological situations and slope shape as the example slope presented in this paper. The method in engineering is of theoretical significance and practical application value.