结构工程师
結構工程師
결구공정사
STRUCTURAL ENGINEERS
2014年
4期
162-169
,共8页
方林%张波%韦欣欣%金国芳
方林%張波%韋訢訢%金國芳
방림%장파%위흔흔%금국방
基坑施工%既有砌体结构%时间效应%沉降%角变位
基坑施工%既有砌體結構%時間效應%沉降%角變位
기갱시공%기유체체결구%시간효응%침강%각변위
excavation%existing masonry structures%time effect%settlement%angular distortion
根据某基坑周边2幢既有建筑的现场实测数据,分析了软土地区考虑时间效应后基坑施工对周边既有砌体结构房屋的影响。基坑开挖完成后,由软土的流变性引起的周边既有建筑沉降具有明显的时间效应。基坑外水位在基坑降水、开挖的过程中相对比较平稳,但降水对周边既有建筑沉降影响较大。距基坑围护墙(1.0~2.0)H 范围内沉降测点由时间效应引起的沉降达到开挖完成时沉降量的1倍左右。三维沉降分布表明既有建筑的沉降形态主要受基坑的三维变形效应和时间效应影响。施工完成后,2幢既有建筑在东西方向上均整体表现为上拱变形,越靠近基坑中部上拱相对变形越大。对2幢既有建筑开裂受损及倾斜情况进行了检测调查,2幢既有建筑最大角变位分别为1/2221、1/1363,表明本基坑施工方案及相关保护措施有效地控制了周边既有建筑的沉降变形,确保了周边既有建筑的结构安全和正常使用。
根據某基坑週邊2幢既有建築的現場實測數據,分析瞭軟土地區攷慮時間效應後基坑施工對週邊既有砌體結構房屋的影響。基坑開挖完成後,由軟土的流變性引起的週邊既有建築沉降具有明顯的時間效應。基坑外水位在基坑降水、開挖的過程中相對比較平穩,但降水對週邊既有建築沉降影響較大。距基坑圍護牆(1.0~2.0)H 範圍內沉降測點由時間效應引起的沉降達到開挖完成時沉降量的1倍左右。三維沉降分佈錶明既有建築的沉降形態主要受基坑的三維變形效應和時間效應影響。施工完成後,2幢既有建築在東西方嚮上均整體錶現為上拱變形,越靠近基坑中部上拱相對變形越大。對2幢既有建築開裂受損及傾斜情況進行瞭檢測調查,2幢既有建築最大角變位分彆為1/2221、1/1363,錶明本基坑施工方案及相關保護措施有效地控製瞭週邊既有建築的沉降變形,確保瞭週邊既有建築的結構安全和正常使用。
근거모기갱주변2당기유건축적현장실측수거,분석료연토지구고필시간효응후기갱시공대주변기유체체결구방옥적영향。기갱개알완성후,유연토적류변성인기적주변기유건축침강구유명현적시간효응。기갱외수위재기갱강수、개알적과정중상대비교평은,단강수대주변기유건축침강영향교대。거기갱위호장(1.0~2.0)H 범위내침강측점유시간효응인기적침강체도개알완성시침강량적1배좌우。삼유침강분포표명기유건축적침강형태주요수기갱적삼유변형효응화시간효응영향。시공완성후,2당기유건축재동서방향상균정체표현위상공변형,월고근기갱중부상공상대변형월대。대2당기유건축개렬수손급경사정황진행료검측조사,2당기유건축최대각변위분별위1/2221、1/1363,표명본기갱시공방안급상관보호조시유효지공제료주변기유건축적침강변형,학보료주변기유건축적결구안전화정상사용。
Taking the time effect into account,response of existing masonry structures to an adjacent excava-tion in soft clay was analyzed based on the observation data of two buildings in this study.After the excavation of Region 1 ,building settlements induced by the rheology of soft clay had obvious time effect.Although the water level outside the excavation was relatively stable during the process of precipitation and excavation,pre-cipitation had great influence on settlements of adjacent existing buildings.Settlements of the optical survey points caused by time effect in the distance of (1 .0 ~2.0)H apart from the retaining walls can be equal to those at the end of the excavation of Region 1 .It can be concluded from the three-dimensional settlement dis-tributions that the pattern of building settlement was primarily affected by the three-dimensional deformation behavior and time effect of excavation.The global deformation modes of the two buildings experienced hog-ging,relative deflection of which was larger if the location was much closer to the middle of excavation in the east-west direction after construction.Cracking and damage of adjacent buildings was detected and investigated at the site.The maximum angular distortions of the adjacent buildings were 1 /2221 and 1 /1 363 respectively, indicating that settlements of adjacent buildings were effectively controlled by the excavation program and the corresponding protective measurements,and hence the structural safety and normal use of adjacent existing buildings was ensured.