摘要
重力锚锚碇基坑开挖形成的高陡边坡稳定性评价是桥梁安全施工与运营的关键问题。以云南大永高速公路涛源金沙江大桥重力锚锚碇边坡为研究对象,结合现场调查与地质钻孔资料,通过有限元方法、极限平衡理论与Newmark法分析,评价了分级开挖与地震作用下锚碇基坑边坡的稳定性,研究表明,分级开挖过程中边坡潜在滑动面由坡体后部逐渐前移,地震作用下永久位移分为线性增长区、加速发展区与破坏失稳区,锚碇边坡在Ⅷ-Ⅸ度地震下极易失稳;预应力锚索与锚杆加固能大大提高边坡的抗震性能,研究成果可为同类工程所借鉴。
Stability evaluation of high and steep slopes, which are created by the gravity anchorage block foundation excavation,is one of key problems in the safe construction of the bridge and the safe operations of the bridge after construction. This paper presents a case history of the slope stability evaluation on the slope at the gravity anchorage block of Taoyuan Jinshajiang River Crossing Bridge of Da-Yong Expressway project in Yunnan Province. The slope stability evaluations were performed using finite element method, limit equilibrium method and Newmark analysis method with the site-specific soil and rock parameters from the geotechnical borings and site reconnaissance results and under design seismic conditions. The results indicate that, the potential sliding plane gradually moves from the back area to the front area. Under the seismic loading conditions, the permanent deformations can be divided into three zones: linear increase zone, acceleration zone and deformation failure zone. The slopes of anchorage blocks are unstable under the earthquake intensities Ⅷ & Ⅸ. The slopes stabilized with prestressed rock anchors can improve the seismic behavior of these slopes.
作者
段现花
徐安航
罗国成
张振平
付晓东
DUAN Xianhua;XU Anhang;LUO Guocheng;ZHANG Zhenping;FU Xiaodong(Yunnan Dayong Highway Construction Co.Ltd.,Dali 671000;Yunnan Communications Investment&Construction Group Co.Ltd.,Kunming 650200;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071)
出处
《土工基础》
2020年第2期185-189,共5页
Soil Engineering and Foundation
基金
国家自然科学基金(No.51779250)
云南省交通科技项目《云交科教[2017]33号》。
关键词
重力锚
边坡
开挖
地震
动力稳定性
gravity anchorages
slopes
excavation
earthquake
dynamic stability
