A MODIFIED GEDDES?S SOLUTION FOR FOUNDATION ADDITIONAL STRESS INDUCED BY X-SECTION PILE
LU Yaru1，LIU Hanlong1，WANG Xinquan2， NG Wang-wai Charles3，DING Xuanming1，4
(1. Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering，Hohai University，Nanjing，Jiangsu 210098，China；2. Department of Civil Engineering，Zhejiang University City College，Hangzhou，Zhejiang 310015，China；3. Department of Civil Engineering，The Hong Kong University of Science and Technology，Hong Kong 999077，China；4. National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety，Hohai University，Nanjing，Jiangsu 210098，China)
Abstract：As a new cross-sectional shaped pile，the stress distribution in soil induced by the side friction(SF) and the end bearing(EB) of X-section cast-in-place concrete(XCC) pile has not been studied completely. Stress distribution in soil estimated by Geddes?s solution has obvious difference owing to independent of the influence of pile radius and pile shapes as the bases of St. Venant?s principle. Based on the Geddes?s solution，the soil stress can be obtained by application of the double integration. This method can be called as modified Geddes?s solution. The soil stress obtained by Geddes?s solution and modified Geddes?s solution are compared. The results indicate that the difference induced by Geddes?s solution increases with the increasing of pile radius because of the shaped effect. Besides，soil stresses induced by the SF and EB of XCC piles with different cross-sectional dimensions are analyzed through the modified Geddes?s solution. The results indicate that the stress in subsoil induced by XCC pile is about 1/3 times that induced by the circular pile with the same cross-sectional area；and the stress due to EB of XCC pile is 1 to 2 times that of circular pile. For large zone of subsoil (below the depth of 1.05 pile length)，the stress induced by SF on concave surface is larger than that induced by flat surface. The stress due to SF on the flat surface increases and that due to the concave surface decreases with the increasing of SF ratio of flat surface to concave surface. The stress induced by EB on concave zone is 1 time to 3 times that on the flat zone. The stress induced by XCC pile is always smaller than the circular pile. As the basis of the comparison analysis of the settlement of single pile，a conclusion can be drawn that the modified Geddes?s solution is more suitable for estimating the stress distribution and settlement of XCC pile than Geddes?s solution.
吕亚茹1，刘汉龙1，王新泉2，吴宏伟3，丁选明1，4. 现浇X形桩产生地基附加应力的修正Geddes应力解[J]. 岩石力学与工程学报, 2013, 32(2): 349-362.
LU Yaru1，LIU Hanlong1，WANG Xinquan2， NG Wang-wai Charles3，DING Xuanming1，4. A MODIFIED GEDDES?S SOLUTION FOR FOUNDATION ADDITIONAL STRESS INDUCED BY X-SECTION PILE. , 2013, 32(2): 349-362.
2013, Vol. 32 
