真空預壓施工

真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)預(yu)(yu)壓(ya)(ya)(ya)法(fa)就是在(zai)需(xu)要加固的(de)軟(ruan)基(ji)中(zhong)插(cha)入豎向(xiang)排(pai)(pai)(pai)(pai)水(shui)通道（如砂井、袋(dai)裝(zhuang)砂井或塑(su)料排(pai)(pai)(pai)(pai)水(shui)板等(deng)），然后在(zai)地面鋪設(she)一(yi)層砂墊層，再在(zai)其(qi)上(shang)覆蓋一(yi)層不(bu)透氣的(de)薄膜(mo)。在(zai)膜(mo)下抽(chou)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)形成負(fu)壓(ya)(ya)(ya)（相(xiang)對大氣壓(ya)(ya)(ya)而(er)言)），負(fu)壓(ya)(ya)(ya)沿豎向(xiang)排(pai)(pai)(pai)(pai)水(shui)通道向(xiang)下傳(chuan)遞 土體(ti)與豎向(xiang)排(pai)(pai)(pai)(pai)水(shui)通道的(de)不(bu)等(deng)壓(ya)(ya)(ya)狀態又使負(fu)壓(ya)(ya)(ya)向(xiang)土體(ti)中(zhong)傳(chuan)遞，在(zai)負(fu)壓(ya)(ya)(ya)作用(yong)下，孔隙水(shui)逐漸滲流(liu)(liu)到豎向(xiang)排(pai)(pai)(pai)(pai)水(shui)通道中(zhong)而(er)達到土體(ti)排(pai)(pai)(pai)(pai)水(shui)固結、強度增長的(de)效果(guo)。真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)預(yu)(yu)壓(ya)(ya)(ya)法(fa)作為(wei)新(xin)一(yi)代軟(ruan)基(ji)加固方法(fa)，以其(qi)工(gong)期(qi)短、施(shi)工(gong)安(an)全、無污染環境(jing)、費用(yong)低等(deng)優點(dian)而(er)廣(guang)泛(fan)應(ying)(ying)用(yong)于港口、碼頭、機(ji)場、工(gong)業(ye)與民用(yong)建筑等(deng)工(gong)程(cheng)建設(she)，但理論研究的(de)落后限制了其(qi)工(gong)程(cheng)上(shang)的(de)進一(yi)步推(tui)廣(guang)應(ying)(ying)用(yong)。用(yong)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)預(yu)(yu)壓(ya)(ya)(ya)加固軟(ruan)土地基(ji)，在(zai)固結過程(cheng)中(zhong)不(bu)僅土體(ti)產生(sheng)垂直沉降，側向(xiang)也會產生(sheng)向(xiang)著負(fu)壓(ya)(ya)(ya)源的(de)水(shui)平(ping)位移(yi)。當在(zai)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)預(yu)(yu)壓(ya)(ya)(ya)的(de)影(ying)響(xiang)范圍內有(you)其(qi)他建筑設(she)施(shi)時，使用(yong)該法(fa)可能(neng)會危及(ji)其(qi)上(shang)部結構物(wu)的(de)安(an)全。真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)預(yu)(yu)壓(ya)(ya)(ya)法(fa)施(shi)工(gong)流(liu)(liu)程(cheng)如下：測量(liang)(liang)放線(xian)→鋪設(she)主(zhu)支(zhi)濾排(pai)(pai)(pai)(pai)水(shui)管→鋪設(she)上(shang)層砂墊層→砂面整平(ping)→鋪設(she)聚氯(lv)乙(yi)烯薄膜(mo)→施(shi)工(gong)密封溝→設(she)置測量(liang)(liang)標(biao)志→安(an)裝(zhuang)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)泵→抽(chou)真(zhen)(zhen)(zhen)空(kong)(kong)(kong)(kong)預(yu)(yu)壓(ya)(ya)(ya)固結土層。