Study Of The Safety Assessment Technique For Existing Gravity Retaining Wall

Gravity retaining wall plays an important role in the existing railways retaining engineering in China. After having been put into use, many of these gravity retaining walls have fallen into varying degrees of instability. Various factors have changed the force exerted on the retaining walls and effected their security status, such as the increase of railway running speeds, axle loads, the related standard changes, and the Wenchuan"5.12" earthquake, But so far, little attention has been paid to the researching of retaining wall structure safety in China, and research about the safety assessment of existing gravity retaining walls is inadequate. As a result, researching the safety of the existing gravity retaining walls must be strengthened now.Based on a broad spectrum or research and theoretical analysis, addressing the safety assessment technology for the gravity retaining wall, this paper will be divided into the following parts:(1) Comprehensive research and analysis on the existing gravity retaining wall safety assessment of current research status, summed up five kinds of common failure forms, including foundation sliding failure, toppling failure, foundation uneven settlement, structural damage of the wall, sliding failure along the weak layer, and a discussion of their respective failure mechanisms.(2) Analysis of the safety assessment system for the existing gravity retaining wall, and expounds the process of safety assessment, and explores existing gravity retaining wall of the dangerous and harmful factors and safety assessment unit.(3) Discussion of the safety coefficient method for existing gravity retaining walls, according to existing gravity retaining wall safety degree, division of the project status of the existing gravity retaining wall into six security levels and corresponding security states, based on this, division the safety coefficient method into two parts, including general assessment and detailed assessment, and provides an explanatory formula for establishing retaining wall security levels and corresponding safety assessment standards.(4) Description of the detailed assessment process for the safety coefficient method for safety assessment through a case-study concerning concrete engineering, as well as drawing the corresponding level of security and safety condition assessment conclusion. There will also be discussion of the influential trends of safety standards when the retaining wall is in the earthquake and rainy days, and conclude with predictions about possible events that might destroy the existing wall.