Arching in geogrid-reinforced pile-supported embankments over silty clay of medium compressibility: Field data and analytical solution

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• 作者：Chonglei Zhang^a ; ^b ; ^c ; ^{chongleizhang2010@163.com" class="auth_mail" title="E-mail the corresponding author} ; Guanlu Jiang^c ; ^{wgljiang@home.swjtu.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Xianfeng Liu^b ; ^c ; ^{Xianfeng.liu@newcastle.edu.au" class="auth_mail" title="E-mail the corresponding author} ; Olivier Buzzi^b ; ^{Olivier.buzzi@newcastle.edu.au" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Arching effect ; Analytical method ; Load transfer ; Embankment ; Piles ; Field test
• 刊名：Computers and Geotechnics
• 出版年：2016
• 出版时间：July 2016
• 年：2016
• 卷：77
• 期：Complete
• 页码：11-25
• 全文大小：4586 K

文摘

The objective of this study is to improve the understanding of load transfer mechanism of Geogrid-Reinforced Pile-Supported Embankments (GRPS) via a new 3D analytical approach and comprehensive field tests. A full-scale embankment was built over a silty clay of medium compressibility as a part of the Liuzhou-to-Nanning High-speed Railway (LNHR) in China. Six sections of the embankment have been heavily instrumented producing comprehensive data of high quality. Field measurements evidence the existence of soil arching, membrane contribution and ground reaction, phenomena that are all contributing to load transfer mechanism. The new 3D analytical arching model accounts for a triangular arrangement of piles and, unlike existing methods, accounts for all relevant components of load transfer mechanisms. In addition, two key parameters were introduced in the model: an elastoplastic state parameter of soil arching (α) and a coefficient of equivalent uniform stress (β). The former was used to satisfy the load equilibrium in case of partial arching while the latter was adopted to allow possible nonuniform vertical stress acting on the ground surface. The so-called ground reaction method was incorporated in an innovative manner to take into account the reactive support of the subsoil beneath geogrid-reinforced layer when estimating the tension development in the geogrid. Finally, the performance of the proposed model was assessed against several existing models and field measurements. Results showed that the new model presented herein outperforms existing models and satisfactorily predicts both the pile efficiency and tension development within the geogrid.