Effects of Reinforcement Length on Deformation Characteristics and Reinforcement Tensile Force of Geosynthetics-Reinforced Soil Structures

• Main Authors: TSAI, MIN-HSIU, 蔡旻修
• Other Authors: WU, PO-KAI
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/734488

碩士 === 國立雲林科技大學 === 營建工程系 === 107 === In this study, a series of plane strain model tests on wrap-faced geogrid-reinforced soil (GRS) retaining wall were conducted to investigate the effects of reinforcement length on its deformation characteristics and the mobilized reinforcement tensile force. Two types of coarse-grained soils, namely, sand and gravel, were adopted as the backfills of GRS retaining wall. A PET geogrid with its nominal strength 150 kN × 30 kN was used. The dimensions of the model wall were 172.6 cm (length) × 80 cm (width) × 112 cm (height). A strip footing of 30 cm wide, having its setback distance equal to 50cm was located on the surface of backfill to resist the applied vertical load during model test. By using photogrammetric analysis method, the deformation patterns of soil mass, the lateral movement of facing and the progressive failure process of soil based on the calculated shear strain contours were also obtained. In this study, the tensile strain of geogrid based on the measured data of the strain gauge attached on the surface were proved to be identically the same as those value obtained from standard method of ASTM D6637. The test results show that under the same vertical settlement of footing, the longer length of geogrid, the higher applied footing bearing vertical stress. Under the same vertical displacement of footing, the lateral movement of facing of GRS retaining wall with shorter length of geogrid was larger than the same type GRS wall but having longer geogrid in the first layer. The maximum tensile strain was found to be at the intersection point of the shear zone for all GRS walls, but the maximum value in gravel is larger than that in sand. To sum up, the ultimate bearing capacity, the lateral deformation of facing, the tensile strain of geogrid and the deformation pattern of soil were found to be significantly influenced by the length of geogrid.