Research Paper Interpretation: Improved limit analysis method of piled slopes considering the pile axial forces

Bridge piles are built on steep slopes in some complex mountainous areas, forming the whole system of mechanical property by slopes, piers and piles. Measures are reinforced by safeguarding slopes. In this circumstance, the complex force poses a challenge to the safe construction of bridge piles. How to take scientific and appropriate measures to protect slopes is a must for the security of bridge piles.

Xiao Shiguo, a professor of Southwest Jiaotong University, published a research paper namedImproved limit analysis method of piled slopes considering the pile axial forcesin the journalGeotechnical Engineeringwith his team.

Introduction to the research paper

Under the landslide thrust, anti-slide piles reinforcing a slope are mainly involved in the bending moment and shear force. The bending moment and shear force were generally involved in the internal force of the piles without considering the axial force in the analysis of the stability of the slope reinforced with anti-slide piles with kinematical limit analysis in the past. However, in terms of the stability of the slope reinforced with anti-slide piles with kinematical limit analysis, the axial force of the piles is actually involved in work rate (usu. anti-slide effect). Therefore, the axial force shall not be ignored in theory.

Based on the upper-bound limit analysis method with kinematical limit analysis, the analysis of frictional resistance of laterally loaded piles, consideration of the axial force of the piles into the anti-slide work rate, the analysis of the stability of the soil slope reinforced with anti-slide piles in light of the axial force of the piles, calculation results obtained from the maximum shear force are carried out. According to practical examples, if the axial force is considered, the shear force of piles will slightly decrease and the bending moment will diminish to some extent while the axial force has a non-conservative effect on the internal force of the piles and puts a remarkable impact on the slip surface. If the axial force is involved, the depth of the slip surface will be widened and designed piles will be longer particularly under a smaller design factor of safety when the axial force’s benefit for conservative design of the pile length is considered.

Other Information

Information About the Author

Shiguo Xiao

Professor of Southwest Jiaotong University, Supervisor of Doctorate Candidates

He is a winner of Support Program for New Century Excellent Talents of the Ministry of Education, National Engineering Register (Geotechnical Engineering), Standing Director of Red Bed Branch of Chinese Society for Rock Mechanics & Engineering (CSRME), and Overseas High-level Talent in Sichuan Province. He has had a long-term career in scientific research and teaching in fields like geotechnical mechanics and subgrade engineering, slope and foundation project and geological disaster prevention and control, in the fields of railway, highway, architecture, pipeline, municipality and hydraulic engineering, etc. He scored remarkable achievements in theories like calculation theory and stability analysis of slope or slide in retaining structures such as anti-slide pile, anchorage structure, retaining wall, etc. He has led over more than 20 national and provincial scientific research projects. He published more than 100 scientific and technical papers in his major whether as the first author or corresponding author (his student as the first one) in important academic journals both at home and abroad such asGeotechnique, Canadian Geotechnical Journal,Soils and Foundations,International Journal for Numerical and Analytical Methods in Geomechanics,Proceedings of the Institution of Civil Engineers-Geotechnical Engineering ICE,Chinese Journal of Geotechnical Engineering,Chinese Journal of Rock Mechanics and Engineering,Rock and Soil Mechanics,China Civil Engineering Journal, among which there are over 20 SCI journals, more than 70 EI journals, and his papers have been cited for over 1,500 times, with the highest number of citations per article more than 700. He has been patented nearly 20 times at the national level, as the winner of the first prize for two projects and the second prize for one in Chinese Society for Rock Mechanics & Engineering (CSRME) and the first prize for three projects in China Railway Engineering Group Limited. He was also a 2012 Winner of the 1st Gu DeZhen Youth Award of Engineering Geology Commission, Geology Society of China (eight in total in China), 2013 Winner of Support Program for New Century Excellent Talents of the Ministry of Education, 2014 Winner of Jiusan Society Chengdu Outstanding Youth (three in total), 2016 Winner of Special Award in Zhan Tianyou Development Foundation for Science and Technology, and 2017 SWJTU Tanglixin Outstanding Scholar.