真空預壓施工

真(zhen)(zhen)空預(yu)(yu)(yu)壓(ya)(ya)(ya)法就(jiu)是在需(xu)要加(jia)(jia)固(gu)(gu)的(de)軟(ruan)基(ji)中插入豎向(xiang)排(pai)(pai)(pai)(pai)水(shui)通道（如砂(sha)井(jing)、袋裝(zhuang)砂(sha)井(jing)或塑料(liao)排(pai)(pai)(pai)(pai)水(shui)板等(deng)），然后(hou)(hou)在地面(mian)(mian)鋪設(she)一層砂(sha)墊層，再在其(qi)(qi)上覆蓋一層不透氣的(de)薄膜(mo)。在膜(mo)下(xia)抽真(zhen)(zhen)空形(xing)成負(fu)壓(ya)(ya)(ya)（相對(dui)大氣壓(ya)(ya)(ya)而(er)(er)言(yan))），負(fu)壓(ya)(ya)(ya)沿豎向(xiang)排(pai)(pai)(pai)(pai)水(shui)通道向(xiang)下(xia)傳遞 土(tu)體(ti)與(yu)豎向(xiang)排(pai)(pai)(pai)(pai)水(shui)通道的(de)不等(deng)壓(ya)(ya)(ya)狀態又(you)使(shi)負(fu)壓(ya)(ya)(ya)向(xiang)土(tu)體(ti)中傳遞，在負(fu)壓(ya)(ya)(ya)作(zuo)用(yong)(yong)(yong)下(xia)，孔隙水(shui)逐漸滲流(liu)到(dao)豎向(xiang)排(pai)(pai)(pai)(pai)水(shui)通道中而(er)(er)達到(dao)土(tu)體(ti)排(pai)(pai)(pai)(pai)水(shui)固(gu)(gu)結、強度增長(chang)的(de)效果(guo)。真(zhen)(zhen)空預(yu)(yu)(yu)壓(ya)(ya)(ya)法作(zuo)為新一代(dai)軟(ruan)基(ji)加(jia)(jia)固(gu)(gu)方法，以其(qi)(qi)工(gong)(gong)(gong)期(qi)短、施(shi)(shi)工(gong)(gong)(gong)安(an)全、無污染(ran)環(huan)境、費(fei)用(yong)(yong)(yong)低等(deng)優點而(er)(er)廣泛應(ying)用(yong)(yong)(yong)于港口(kou)、碼頭、機場、工(gong)(gong)(gong)業(ye)與(yu)民用(yong)(yong)(yong)建筑(zhu)等(deng)工(gong)(gong)(gong)程建設(she)，但理論(lun)研究的(de)落后(hou)(hou)限制了(le)其(qi)(qi)工(gong)(gong)(gong)程上的(de)進一步推(tui)廣應(ying)用(yong)(yong)(yong)。用(yong)(yong)(yong)真(zhen)(zhen)空預(yu)(yu)(yu)壓(ya)(ya)(ya)加(jia)(jia)固(gu)(gu)軟(ruan)土(tu)地基(ji)，在固(gu)(gu)結過(guo)程中不僅土(tu)體(ti)產生(sheng)垂直沉(chen)降，側(ce)向(xiang)也會(hui)產生(sheng)向(xiang)著負(fu)壓(ya)(ya)(ya)源的(de)水(shui)平位(wei)移。當在真(zhen)(zhen)空預(yu)(yu)(yu)壓(ya)(ya)(ya)的(de)影響范圍內有其(qi)(qi)他建筑(zhu)設(she)施(shi)(shi)時，使(shi)用(yong)(yong)(yong)該法可能會(hui)危及其(qi)(qi)上部(bu)結構物的(de)安(an)全。真(zhen)(zhen)空預(yu)(yu)(yu)壓(ya)(ya)(ya)法施(shi)(shi)工(gong)(gong)(gong)流(liu)程如下(xia)：測量(liang)放線→鋪設(she)主支濾排(pai)(pai)(pai)(pai)水(shui)管→鋪設(she)上層砂(sha)墊層→砂(sha)面(mian)(mian)整平→鋪設(she)聚氯乙烯薄膜(mo)→施(shi)(shi)工(gong)(gong)(gong)密封(feng)溝→設(she)置(zhi)測量(liang)標志→安(an)裝(zhuang)真(zhen)(zhen)空泵→抽真(zhen)(zhen)空預(yu)(yu)(yu)壓(ya)(ya)(ya)固(gu)(gu)結土(tu)層。