虹吸联合堆载预压排水固结效果模型试验  

Consolidation model test of siphon drainage with preloading

作　　者：陈柯星 郎凌嘉 王旭[2] 吴朝峰 周天翊 孙红月[2] CHEN Ke-xing;LANG Ling-jia;WANG Xu;WU Chao-feng;ZHOU Tian-yi;SUN Hong-yue(China Energy Engineering Group Zhejiang Electric Power Design Institute Co.,Ltd.,Hangzhou 310058,Zhejiang,China;Ocean College,Zhejiang University,Zhoushan 316021,Zhejiang,China)

机构地区：[1]中国能源建设集团浙江省电力设计院有限公司,浙江杭州310058 [2]浙江大学海洋学院,浙江舟山316021

出　　处：《地基处理》2023年第6期477-482,共6页Journal of Ground Improvement

摘　　要：软土具有高压缩性、高含水量、低渗透性和低强度等特点,排水固结是提高软土地基强度、减小工后沉降的重要手段。本文突破传统的井孔排水理念,利用虹吸免动力实现水体跨越输送的物理特性,提出了一种井点抽水控制群管虹吸的排水方案,以解决低渗透软土无法直接动力抽排地下水的物理制约问题。为了验证虹吸联合堆载预压方法的有效性,本文采用室内物理模型试验,通过测试虹吸排水流量变化情况、排水引起软土内部孔隙水压力变化特征、土体表面沉降变形特性,分析应用虹吸联合堆载预压的作用效果。试验证明在单纯虹吸排水、单纯堆载预压固结以及虹吸联合堆载预压固结3种工况中,虹吸联合堆载预压固结方法下的土体排水流量最大,虹吸对于降低软土体内的地下水作用显著,可将模型箱内软土中的水位下降至模型箱底部。通过80 d的排水固结试验,单纯虹吸排水引起的沉降值约为8 mm,仅堆载预压引起的沉降为12 mm,虹吸联合堆载预压引起沉降为16 mm,证明了虹吸联合堆载预压固结方法的优势。Due to the high compressibility,high water content,low permeability and limited strength in soft soil,drainage consolidation proves to be a crucial approach for enhancing the strength of foundation in soft soil and diminishing construction-induced settlement.In contrast to conventional methods,siphons exploit their physical properties to transport water without requiring power.Utilizing a water collection scheme that employs a network of well pipes using siphon technology proves to be an effective strategy for overcoming the physical barriers presented by low-permeability soft soil,allowing water to be transported directly.This work assesses alterations in siphon drainage flow,variations in pore water pressure induced by drainage in soft soil,and the settlement and deformation characteristics of the soil surface through siphon-combined preloading model tests.Findings reveal that in model tests conducted under three distinct conditions,solely siphon drainage,exclusive preloading consolidation,and the combination of siphon drainage with preloading consolidation,the combination of siphon drainage with preloading consolidation demonstrates the highest soil drainage flow.Siphon plays a significant role in reducing the groundwater in the soft soil,and it can reduce the water level in the model box to its base.After 80 days of drainage and consolidation,the settlement value caused by siphon drainage is about 8 mm,the settlement caused by only preloading is 12 mm,and the settlement caused by siphon-combined preloading is 16 mm.Experimental findings substantiate the advantages of the siphon-combined preloading consolidation method.

关 键 词：软土 排水固结 虹吸排水 堆载预压 虹吸联合堆载预压排水 模型试验 

分 类 号：TU41[建筑科学—岩土工程]