新夏港双线船闸单锚板桩结构受力特性分析

Mechanical behavior of single anchor sheet pile structure in Xinxiagang double-lane ship lock

为研究新夏港双线船闸闸室单锚板桩结构的受力特性,利用ABAQUS有限元软件进行建模分析。考虑施工过程,讨论闸室开挖问题中土体本构模型的选择。对施工期和运行期单锚板桩结构的受力特性进行分析,得到板桩的变形和弯矩分布规律以及板桩前后土压力的发展状况。结果表明:在施工开挖过程中,修正剑桥模型能够更好地反映土体卸载回弹特性;在施工完建期,桩后土压力表现为经典的"R"型分布,桩前土压力基本为直线分布,但在开挖面处由于板桩变形挤压会产生局部应力增大现象;在船闸运行期,水位变动频繁,水压力指向闸室时所引起的压力增量,底板横撑的分担比可达到80%,说明横撑能够有效改善板桩结构的受力状态。

In order to analyse the mechanical characteristics of single anchor sheet pile structure in Xinxiagang double-lane lock, we establish the finite mesh model with ABAQUS.We discusse the choice of soil constitutive model during the excavation of chamber after contruction process has been taken into consideration.At the same time,we get the distribution of deformation and bending moment and the variaty of earth pressure before and after the sheet pile by analyzing the force characteristics of single anchor sheet pile structure during the construction and using period.The results show that for deep excavation problem, modified Cam-Clay model can reflect the bulk properties of soil better and when the construction is completed the earth pressure behind the piles performs the classic ＂R＂ type distribution while the earth pressure before the pile is basically a straight line,but in the face of the excavation,the stress will increase substantially due to the deformation and squeeze of sheet pile.During the using period of the lock,water level changes frequently and the floor brace can bear about 80% of the pressure increment caused by the water pressure.That means it can effectively improve the stress state of the sheet pile structure.