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(上海建筑設計研究院有限公司 上海申元巖土工程有限公司, 上海 200011)
摘要: 基于上海世博 B06 地塊深大基坑工程,根據(jù)場地臨近黃浦江、場地分布有深厚承壓水層、周邊環(huán)境非常敏感等條件,采取了分坑施工、懸掛式止水帷幕和坑外設置回灌井等一系列技術措施. 通過現(xiàn)場單井抽水試驗,取得了承壓水含水層的詳細水文力學參數(shù);通過現(xiàn)場群井抽水試驗,獲得了承壓水水位降深與地面沉降的初步關系.采用數(shù)值分析方法建立三維滲流模型,研究了不同止水帷幕深度下,坑內降壓對坑外環(huán)境的不利影響,并結合坑外環(huán)境對象的保護要求,確定了合理的懸掛式止水帷幕深度(42m). 實施結果和監(jiān)測數(shù)據(jù)表明,采取的技術措施有效地減小了基坑坑內降壓引起的坑外水位降深,保證了周邊環(huán)境的安全.
關鍵詞: 基坑工程; 深厚承壓水層; 現(xiàn)場抽水試驗; 三維滲流分析; 懸掛式止水帷幕
中圖分類號:TU46+3 文獻標志碼:A 文章編號:1002-848X(2023)01-0129-06
DOI:10. 19701 / j. jzjg. SHY2321
Design and practice of supporting structure of riverside deep and largefoundation pit project with deep confined water layer
LIANG Zhirong, LI Chengwei, LI Wei, WEI Xiang, LIU Jingde
(Shanghai Shenyuan Geotechnical Engineering Co. , Ltd. , Shanghai Institute of ArchitecturalDesign & Research Co. , Ltd. , Shanghai 200011, China)
Abstract: Based on the deep and large foundation pit project of Shanghai EXPO B06 block, according to the conditions ofthe site near Huangpu river, the site distribution with deep confined water layer, and very sensitive surroundingenvironment, a series of technical measures such as pit-dividing construction, suspended impervious curtain and rechargewell outside the pit were adopted. Through the field single well pumping test, the detailed hydromechanical parameters ofconfined water aquifer were obtained. Through the field group well pumping test, the preliminary relationship between thedrawdown of confined water level and land subsidence was obtained. The three-dimensional seepage model was establishedby numerical analysis method, and the adverse effects of water pressure reduction in the pit on the environment outside thepit were studied under different impervious curtain depths. Combined with the protection requirements of the environmentalobjects outside the pit, the reasonable impervious curtain depth( 42m) was determined. The implementation results andmonitoring data show that the technical measures adopted effectively reduce the drawdown of water level outside the pitcaused by water pressure reduction in the foundation pit, which ensures the safety of the surrounding environment.
Keywords:foundation pit project; deep confined water layer; field pumping test; three-dimensional seepage analysis;suspended impervious curtain
∗上海市青年科技啟明星計劃資助(20QB1400600、20QB1404500),上海市優(yōu)秀技術帶頭人計劃資助(22XD1432800),華建集團科研計劃項目(18-1 類-0081-地、22-1 類-0096-地).
作者簡介:梁志榮,碩士,教授級高級工程師,主要從事巖土工程設計研究,Email:llq009@ vip. sina. com.
[引用本文] 梁志榮,李成巍,李偉,等. 深厚承壓水層下臨江深大基坑工程支護結構設計與實踐[ J]. 建筑結構,2023,53(1):129-134. LIANG Zhirong,LI Chengwei,LI Wei,et al. Design and practice of supporting structure of riversidedeep and large foundation pit project with deep confined water layer [J]. Building Structure,2023,53(1):129-134.
