CALCULATION STUDY OF RANKINE EARTH PRESSURE BASED ON UNIFIED STRENGTH THEORY
ZHANG Jian1，2，HU Ruilin1，LIU Haibin3，WANG Sansan1
(1. Key Laboratory of Engineering Geomechanics，Institute of Geology and Geophysics，Chinese Academy of Science，Beijing 100029，China；2. Department of Civil engineering，Nanyang Normal University，Nanyang，Henan 473061，China； 3. China Huashui Hydropower Development Corporation，Beijing 100069，China)
Abstract：The issue of wall earth pressure will be regarded as problem of plane strain，so intermediate principal stress is calculated by generalized Hook¢s law in plane strain assumption. The principal stress in accordance with the principle of Rankine earth pressure is determined. On this basis，the formula of Rankine earth pressure is derived when the expression of principal stress in double-shear unified strength theory is used. The weighted coefficient b considering effects of intermediate principal stress and the Poisson's ratio is introduced to the formula. The solution based on classical Rankine active earth pressure theory is a special case of the unified solution. The unified solution can be flexibly used to calculate earth pressure of various filled materials. Finally，an example is given to show the impact of their results in different weighted coefficients b. The analytical shows that the result of classical Rankine passive earth pressure theory is smaller，so it often causes the potential danger. However，the result of classical Rankine active earth pressure theory is larger and has enough safety storage. The potential strength of filling materials is sufficiently developed under the guidance of the double-shear unified strength theory，so some economic benefits can be obtained.
