CAJ | 학술논문

基坑减压降水的幅度与群井效应密切相关。某超大面积基坑，含水层组厚40m，中下部透水性强，采用非完整井降水。对水文地质条件概化，建立了地下水三维非稳定流数值模型，对均匀布置群井、不均匀布置群井、分块开挖降水、不同的井结构、布设回灌井等工况，进行了渗流场模拟。研究表明，强透水性含水层超大面积基坑降水的群井效应极为明显；井位角密中疏布置，可实现降深调平，避免降深不足和超降；基坑分块降水，可减少坑外降深；短滤管井结构可减少基坑总涌水量和坑外降深；强透水性含水层可灌性强，回灌对减少坑外水位下降有较明显的效果。模拟结果与现场监测较为一致。研究成果可为类似工程地下水控制设计提供参考。
기갱감압강수적폭도여군정효응밀절상관。모초대면적기갱，함수층조후40m，중하부투수성강，채용비완정정강수。대수문지질조건개화，건립료지하수삼유비은정류수치모형，대균균포치군정、불균균포치군정、분괴개알강수、불동적정결구、포설회관정등공황，진행료삼류장모의。연구표명，강투수성함수층초대면적기갱강수적군정효응겁위명현；정위각밀중소포치，가실현강심조평，피면강심불족화초강；기갱분괴강수，가감소갱외강심；단려관정결구가감소기갱총용수량화갱외강심；강투수성함수층가관성강，회관대감소갱외수위하강유교명현적효과。모의결과여현장감측교위일치。연구성과가위유사공정지하수공제설계제공삼고。
Water head drawdown during dewatering in confined aquifers closely relates to multi-well effect.An ultra-large pit is studied in this paper.The pit features 40-meter-thick aquifers,is high permeability at middle and down side,and uses partial pumping wells.Based on the summarization of hydrogeological conditions,a three dimensional unsteady-flow numerical model of underground water is built and used to simulate the seepage field under different scenarios.They include even and uneven distribution of wells,excavation and dewatering by blocks, various well structures and deployment of injection wells.The research shows (1)Ultra-large pit in highly permeable aquifers has obvious multi-well effect;(2)“Dense at Corner and Sparse at Center”well deployment unifies water head drawdown and avoids insufficient or excessive dewatering;(3 )Excavation and dewatering by blocks suppresses drawdown outside the pit;(4)Well structure with short screen pipe reduces total water yield and suppresses outside drawdown;(5)Aquifers of high permeability are highly rechargeable and recharging has fairly obvious effect on suppressing outside drawdown.Simulation results are consistent with in-situ monitoring.The research result can serve as a reference to similar underground water level control project.