地下结构排水盲沟减压抗浮简化设计方法  

Simplified design method for pressure reduction and anti-floating of blind drains of underground structures

作　　者：潘泓[1,2] 刘荣照 骆冠勇[1,2] 彭斯格 曹洪[1,2] PAN Hong;LIU Rongzhao;LUO Guanyong;PENG Sige;CAO Hong(School of Civil Engineering and Transportation,South China University of Technology,Guangzhou 510640,China;The State Key Laboratory of Subtropical Building Science,South China University of Technology,Guangzhou 510640,China)

机构地区：[1]华南理工大学土木与交通学院,广东广州510640 [2]华南理工大学亚热带建筑科学国家重点实验室,广东广州510640

出　　处：《岩土工程学报》2025年第4期685-694,共10页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(51978282,52308353);广东省自然科学基金项目(2023A1515011571,2023A1515011683);华南理工大学亚热带建筑科学国家重点实验室开放研究项目(2022ZB21)。

摘　　要：目前,排水盲沟减压抗浮系统中排水盲沟设计主要采用数值法分析计算,尚无简单实用的简化计算方法。基于盲沟为等水头边界及入渗量均布于盲沟单元等假定,建立排水盲沟网格简化模型,得到平面布置为矩形的盲沟单元水头分布解析解,给出入渗量、单元几何尺寸等参数即可算得盲沟单元内水头分布。提出均匀入渗和非均匀入渗情况下底板入渗量分布的计算模式。通过算例验证,简化方法适用前提为盲沟及结构底板底部布置有渗透性远大于土体的疏水层,简化算法与有限元结果的相对误差较小且结果偏于保守,可用于盲沟布置的设计。对典型土层算例对比发现:若底板下部地层为弱透水层中夹有一层强透水层,底板入渗量会均匀分布,盲沟可等间距均匀布置;若下部地层无强透水层,入渗量大部分集中在距帷幕1倍~1.5倍坑底含水层厚度范围内,盲沟间距应在该范围内减小,在底板中部增大。At present,the numerical analysis methods are mainly used for the design of blind drains in pressure reduction and anti-floating systems,and there is no simple and practical simplified method.Based on the assumption that a blind drain has an equal water head boundary and the infiltration amount is uniformly distributed in the blind drain unit,a simplified model for the blind drain grid is established.The analytical solution of the water head distribution of the blind drain unit with a rectangular layout is obtained.The water head distribution within the blind drain unit can be calculated by providing the parameters such as the infiltration amount and the geometric size of the unit.A model for calculating the distribution of bottom plate infiltration is proposed under both uniform and non-uniform infiltration conditions.Through numerical examples,it is verified that the simplified method is applicable if there is a hydrophobic layer with permeability much greater than the soil at the bottom of the blind drain and structural bottom plate.The relative error between the simplified algorithm and the finite element results is small and the results tend to be conservative,which can be used for the design of layout of blind drains.By comparing typical soil layers,it is found that if the lower layer of the bottom plate is a weakly permeable one with a layer of strongly permeable layer,the infiltration amount of the bottom plate will be evenly distributed,and blind drains can be evenly arranged at equal intervals.If there is no strongly permeable layer in the lower strata,the infiltration amount is mostly concentrated within the range of 1 to 1.5 times the thickness of the aquifer at the bottom of the pit from the curtain.The distance between blind drains should be reduced within this range and increased in the middle of the bottom plate.

关 键 词：抗浮 排水减压 排水盲沟 渗流 简化方法 

分 类 号：TU43[建筑科学—岩土工程]