摘要
兰溪市某河岸型古城墙不仅担负着老城区的防洪安全重任,而且也是当地重要的历史文化景观。在梅汛期和台汛期,由于连绵阴雨或大暴雨的作用,古城墙存在安全稳定性问题。以该古城墙为研究对象,对古城墙及其墙后土体工程地质进行了勘测,基于MIDAS GTS NX有限元软件,建立了该古城墙在50年一遇降雨强度下的稳定性分析模型,采用边坡—应力—渗流耦合模式对不同降雨历时的古城墙稳定性进行分析。此外,还对加固(倒挂井+防渗帷幕)后古城墙的稳定性进行了数值模拟和分析。结果表明:古城墙未加固时,在遭遇50年一遇降雨入渗条件下,墙后孔隙水压力持续增大,3 d后城墙失稳。采用倒挂井+防渗帷幕加固后,墙后孔隙水压明显减小,基质吸力的消散得到抑制,最危险滑动面向深层移动,稳定性显著提升。
A riparian ancient city wall in Lanxi is not only responsible for the flood defense safety for the old urban district but also an important historic and cultural heritage site.The safety and stability problem of the ancient city wall is caused by the continuous rain or heavy storm during the periods of plum rain and typhoon flood.By taking the ancient city wall as the study object,the engineering geological survey of the ancient city wall and its earth-fill mass behind the wall are carried out.Based on the MIDAS GTS NX finite element software,the stability analysis model of the ancient city wall under once-in-50-year rainfall is established.The stability of the ancient city wall with different rainfall durations are analyzed using the slope-stress-seepage coupling mode.In addition,the stability of the ancient city wall after reinforced by an inverted well and impervious curtains is numerically simulated and analyzed.The results show that when the ancient city wall is not reinforced,the pore water pressure behind the wall continues to increase under the once-in-50-year rainfall infiltration and the city wall is unstable after three days.After reinforced with the inverted well and impervious curtains,the pore water pressure behind the wall is significantly reduced,the dissipation of matrix suction is restrained,the most dangerous sliding faces move towards deep layers,and the stability is significantly improved.
作者
董志勇
郑晓亭
周建芬
DONG Zhiyong;ZHENG Xiaoting;ZHOU Jianfen(College of Civil Engineering,Zhejiang University of Technology,Hangzhou 310023,China;Key Laboratory for Technology in Rural Water Management of Zhejiang Province,Zhejiang University of Water Resources and Electric Power,Hangzhou 310018,China)
出处
《浙江工业大学学报》
CAS
北大核心
2024年第6期691-698,共8页
Journal of Zhejiang University of Technology
基金
浙江省水利科技计划重大项目(RA1904)。
关键词
古城墙
流—固耦合
孔隙水压
加固措施
稳定性
ancient city wall
fluid-solid coupling
pore water pressure
reinforced measures
stability