真空預壓施工

真(zhen)(zhen)空(kong)(kong)預壓(ya)(ya)(ya)法就是在(zai)(zai)(zai)(zai)需(xu)要加固(gu)(gu)的(de)軟(ruan)基中插(cha)入豎向(xiang)排(pai)(pai)水(shui)通(tong)道（如砂(sha)井、袋裝(zhuang)砂(sha)井或塑料排(pai)(pai)水(shui)板等(deng)(deng)），然后在(zai)(zai)(zai)(zai)地(di)面鋪(pu)設(she)(she)一層砂(sha)墊(dian)層，再在(zai)(zai)(zai)(zai)其(qi)(qi)上(shang)(shang)覆蓋一層不(bu)透氣(qi)的(de)薄(bo)膜(mo)。在(zai)(zai)(zai)(zai)膜(mo)下(xia)抽真(zhen)(zhen)空(kong)(kong)形(xing)成(cheng)負(fu)壓(ya)(ya)(ya)（相(xiang)對(dui)大氣(qi)壓(ya)(ya)(ya)而(er)言(yan))），負(fu)壓(ya)(ya)(ya)沿豎向(xiang)排(pai)(pai)水(shui)通(tong)道向(xiang)下(xia)傳(chuan)(chuan)遞 土體與豎向(xiang)排(pai)(pai)水(shui)通(tong)道的(de)不(bu)等(deng)(deng)壓(ya)(ya)(ya)狀態(tai)又使(shi)負(fu)壓(ya)(ya)(ya)向(xiang)土體中傳(chuan)(chuan)遞，在(zai)(zai)(zai)(zai)負(fu)壓(ya)(ya)(ya)作(zuo)用(yong)(yong)下(xia)，孔(kong)隙水(shui)逐漸滲流到豎向(xiang)排(pai)(pai)水(shui)通(tong)道中而(er)達(da)到土體排(pai)(pai)水(shui)固(gu)(gu)結(jie)、強度增長的(de)效果。真(zhen)(zhen)空(kong)(kong)預壓(ya)(ya)(ya)法作(zuo)為新一代軟(ruan)基加固(gu)(gu)方法，以其(qi)(qi)工(gong)期短(duan)、施工(gong)安全、無污(wu)染(ran)環境(jing)、費用(yong)(yong)低等(deng)(deng)優點而(er)廣泛應用(yong)(yong)于港口、碼頭、機場(chang)、工(gong)業(ye)與民用(yong)(yong)建(jian)筑等(deng)(deng)工(gong)程(cheng)建(jian)設(she)(she)，但理論(lun)研究的(de)落后限制了其(qi)(qi)工(gong)程(cheng)上(shang)(shang)的(de)進一步推廣應用(yong)(yong)。用(yong)(yong)真(zhen)(zhen)空(kong)(kong)預壓(ya)(ya)(ya)加固(gu)(gu)軟(ruan)土地(di)基，在(zai)(zai)(zai)(zai)固(gu)(gu)結(jie)過程(cheng)中不(bu)僅土體產生垂直沉降，側向(xiang)也會產生向(xiang)著負(fu)壓(ya)(ya)(ya)源(yuan)的(de)水(shui)平(ping)位移。當(dang)在(zai)(zai)(zai)(zai)真(zhen)(zhen)空(kong)(kong)預壓(ya)(ya)(ya)的(de)影(ying)響范圍內有(you)其(qi)(qi)他建(jian)筑設(she)(she)施時，使(shi)用(yong)(yong)該法可能會危及其(qi)(qi)上(shang)(shang)部結(jie)構物的(de)安全。真(zhen)(zhen)空(kong)(kong)預壓(ya)(ya)(ya)法施工(gong)流程(cheng)如下(xia)：測量(liang)放線→鋪(pu)設(she)(she)主支濾排(pai)(pai)水(shui)管→鋪(pu)設(she)(she)上(shang)(shang)層砂(sha)墊(dian)層→砂(sha)面整平(ping)→鋪(pu)設(she)(she)聚氯(lv)乙(yi)烯薄(bo)膜(mo)→施工(gong)密封溝→設(she)(she)置測量(liang)標志→安裝(zhuang)真(zhen)(zhen)空(kong)(kong)泵→抽真(zhen)(zhen)空(kong)(kong)預壓(ya)(ya)(ya)固(gu)(gu)結(jie)土層。