The Study of Passive Earth Pressure Provided by Shear Key of Retaining Wall

• Main Authors: Yen-Hui Chang, 張炎輝
• Other Authors: 黃添坤
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/g7e6d6

碩士 === 國立中興大學 === 土木工程學系所 === 107 === Retaining walls are widely used in many projects and facilities in the field of geotechnical engineering for stabilizing dangerous slopes to prevent debris flows and landslides. These walls are sometimes used as soil retaining structures during earth cutting and filling operations. They can be easily designed and modified to satisfy the engineering requirements for a particular site and represent an economical solution to many common engineering problems. The main causes of retaining wall damage are rainstorms and earthquakes, which can increase the force exerted on a wall by backfill. A sudden or excessive surge in compressive force against a retaining wall can result in overturning and sliding failure. Therefore, enhancing the resistance of retaining walls to unexpected disasters based on improved design methodologies has become an urgent engineering task. Numerous design options have been proposed by many engineers, including the installation of a pile foundation at the base of a retaining wall and the installation of shear keys, with the latter option being more cost effective. This study investigated the effects of various shear keys on the strength of retaining walls. Based on the theoretical formulae used as design considerations in the cases studied and numerical analysis performed using the PLAXIS 2D software for the verification of results, the findings of this study indicate the following. (1) According to calculations based on the analysis of various designs, increasing the size of a shear key effectively improves the safety of a retaining wall. Retaining wall designs with a shear key installed at the wall heel can achieve the greatest sliding resistance. (2) Because PLAXIS 2D was not used for the analysis of safety factors in the cases studied, the installation of shear keys was found to have little impact on overall wall deformation and related mechanical behaviors. (3) The installation of shear keys at the wall heel results in the greatest resistance against sliding and overturning in response to both rainstorms and earthquakes. (4) The installation of shear keys, regardless of their specifications and location, significantly enhances the total resistance of retaining walls.