超深竖井基坑抗浮锚筋桩受力特性及布桩参数优化研究  

Study on layering excavation scheme of ultra-deep shaft in soft and hard alternate strata

作　　者：龚兵文 万缘 周王鹏 陈保国[2] GONG Bingwen;WAN Yuan;ZHOU Wangpeng;CHEN Baoguo(Sinohydro Bureau 7 Co.,ltd.,Chengdu 610081,Sichuan,China;Faculty of Engineering,China University of Geosciences,Wuhan 430074,Hubei,China)

机构地区：[1]中国水利水电第七工程局有限公司,四川成都610081 [2]中国地质大学(武汉)工程学院,湖北武汉430074

出　　处：《工程建设》2025年第4期1-5,共5页Engineering Construction

基　　金：中国水利水电第七工程局有限公司科技攻关资助项目(LT-02-ZY-2022-[科研]-01)。

摘　　要：公明超深竖井为罗田-铁岗水库输水干线竖井,其基坑底板高于地下水位约70 m,抗浮问题显著。文章依托于公明超深竖井,利用三维数值模拟,对超深竖井底板抗浮锚筋桩的受力特性及布桩参数优化进行研究。研究发现:锚筋桩布置越靠近底板中心越先发挥拉拔作用,最大轴力也越大,随着锚筋桩布桩位置远离底板中心,其最大轴力逐渐减小;底板中心部位锚筋桩先发挥拉拔作用的同时使基岩向上隆起,外围锚筋桩受基岩隆起影响显著,甚至在桩侧出现了向上的侧摩阻力,表现为轴力骤减,桩侧剪应力减小,有效锚固深度增加的特征;根据模拟结果可将原方案第七、八环锚筋桩合并为一环锚筋桩,优化后锚筋桩最大轴力值增加约9%,低于抗拔承载力设计值,分担的水浮力减小约4%,但节省抗浮锚筋桩数量约23%,满足工程安全需求,经济效益显著。Gongming ultra-deep shaft is a vertical shaft for the water transmission line of Luotian-Tiegang Reservoir.Its foundation pit floor is about 70 m higher than the groundwater level,and the anti-float problem is significant.Based on Gongming ultra-deep shaft,three-dimensional numerical simulation is used to study the force characteristics of anti-float anchor reinforcement pile on the ultra-deep shaft floor and the optimization of pile distribution parameters.It is found that the closer the anchorage reinforcement pile is to the center of the floor,the more it plays the drawing function first,and the greater the maximum axial force is.As the anchorage reinforcement pile is far away from the center of the floor,the maximum axial force decreases gradually.The anchor reinforcement pile in the central part of the bottom plate first plays the role of drawing and at the same time makes the bedrock uplift.The peripheral anchor reinforcement pile is significantly affected by the bedrock uplift,and even appears the lateral friction resistance on the pile side,which is manifested as the axial force decreases sharply,the shear stress on the pile side decreases,and the effective anchorage depth increases.According to the simulation results,the 7th and 8th ring anchor reinforcement piles in the original scheme can be combined into one ring anchor reinforcement piles.After optimization,the maximum axial force value of anchor reinforcement piles increases by about 9%,which is lower than the design value of tensile capacity,and the water buoyancy force shared by anchor reinforcement piles decreases by about 4%,but the number of anti-buoyancy anchor reinforcement piles is saved by about 23%,which meets the engineering safety requirements and has significant economic benefits.

关 键 词：超深竖井基坑 抗浮锚筋桩 受力特性 优化设计 数值模拟 

分 类 号：TU753[建筑科学—建筑技术科学]