真空預壓施工-插打排水板

真(zhen)空(kong)(kong)(kong)(kong)預壓(ya)法(fa)(fa)就是(shi)在(zai)需要加固的(de)(de)軟基中(zhong)插入豎(shu)向(xiang)(xiang)排(pai)水(shui)通(tong)道（如砂(sha)井、袋裝砂(sha)井或塑料排(pai)水(shui)板等），然后在(zai)地(di)(di)面(mian)鋪設一層(ceng)砂(sha)墊(dian)層(ceng)，再在(zai)其上覆蓋(gai)一層(ceng)不透氣的(de)(de)薄(bo)(bo)膜。在(zai)膜下(xia)(xia)抽(chou)真(zhen)空(kong)(kong)(kong)(kong)形成(cheng)負壓(ya)（相對大氣壓(ya)而言)），負壓(ya)沿豎(shu)向(xiang)(xiang)排(pai)水(shui)通(tong)道向(xiang)(xiang)下(xia)(xia)傳遞 土(tu)體與(yu)豎(shu)向(xiang)(xiang)排(pai)水(shui)通(tong)道的(de)(de)不等壓(ya)狀態又使負壓(ya)向(xiang)(xiang)土(tu)體中(zhong)傳遞，在(zai)負壓(ya)作用(yong)(yong)下(xia)(xia)，孔隙水(shui)逐(zhu)漸滲(shen)流(liu)到豎(shu)向(xiang)(xiang)排(pai)水(shui)通(tong)道中(zhong)而達到土(tu)體排(pai)水(shui)固結(jie)、強(qiang)度增長(chang)的(de)(de)效果(guo)。真(zhen)空(kong)(kong)(kong)(kong)預壓(ya)法(fa)(fa)作為新(xin)一代軟基加固方法(fa)(fa)，以其工期短、施(shi)工安全(quan)、無污染(ran)環境(jing)、費用(yong)(yong)低等優(you)點而廣泛應用(yong)(yong)于港口、碼頭、機場、工業(ye)與(yu)民用(yong)(yong)建筑等工程(cheng)(cheng)建設，但理論(lun)研究的(de)(de)落(luo)后限制了其工程(cheng)(cheng)上的(de)(de)進一步(bu)推(tui)廣應用(yong)(yong)。用(yong)(yong)真(zhen)空(kong)(kong)(kong)(kong)預壓(ya)加固軟土(tu)地(di)(di)基，在(zai)固結(jie)過程(cheng)(cheng)中(zhong)不僅(jin)土(tu)體產生垂直(zhi)沉降，側(ce)向(xiang)(xiang)也會(hui)產生向(xiang)(xiang)著負壓(ya)源的(de)(de)水(shui)平位移。當在(zai)真(zhen)空(kong)(kong)(kong)(kong)預壓(ya)的(de)(de)影響(xiang)范圍內有其他建筑設施(shi)時，使用(yong)(yong)該法(fa)(fa)可能(neng)會(hui)危(wei)及其上部(bu)結(jie)構物的(de)(de)安全(quan)。真(zhen)空(kong)(kong)(kong)(kong)預壓(ya)法(fa)(fa)施(shi)工流(liu)程(cheng)(cheng)如下(xia)(xia)：測量放線→鋪設主支濾排(pai)水(shui)管→鋪設上層(ceng)砂(sha)墊(dian)層(ceng)→砂(sha)面(mian)整平→鋪設聚氯乙烯薄(bo)(bo)膜→施(shi)工密封(feng)溝→設置測量標志→安裝真(zhen)空(kong)(kong)(kong)(kong)泵→抽(chou)真(zhen)空(kong)(kong)(kong)(kong)預壓(ya)固結(jie)土(tu)層(ceng)。