真空預壓施工驗收

真(zhen)空(kong)預(yu)(yu)壓(ya)法就是在(zai)(zai)需要加固的(de)(de)(de)軟(ruan)基(ji)中(zhong)插(cha)入豎向排(pai)水(shui)(shui)通(tong)(tong)道(dao)（如(ru)砂(sha)井、袋裝砂(sha)井或塑(su)料排(pai)水(shui)(shui)板等(deng)(deng)），然后在(zai)(zai)地(di)面鋪(pu)設(she)一(yi)層砂(sha)墊(dian)層，再在(zai)(zai)其(qi)上(shang)覆(fu)蓋一(yi)層不透氣的(de)(de)(de)薄膜(mo)。在(zai)(zai)膜(mo)下(xia)(xia)(xia)抽真(zhen)空(kong)形(xing)成(cheng)負壓(ya)（相對大(da)氣壓(ya)而言)），負壓(ya)沿豎向排(pai)水(shui)(shui)通(tong)(tong)道(dao)向下(xia)(xia)(xia)傳(chuan)遞 土體與豎向排(pai)水(shui)(shui)通(tong)(tong)道(dao)的(de)(de)(de)不等(deng)(deng)壓(ya)狀態又使負壓(ya)向土體中(zhong)傳(chuan)遞，在(zai)(zai)負壓(ya)作用(yong)下(xia)(xia)(xia)，孔隙(xi)水(shui)(shui)逐漸滲流到豎向排(pai)水(shui)(shui)通(tong)(tong)道(dao)中(zhong)而達到土體排(pai)水(shui)(shui)固結、強度增長的(de)(de)(de)效果。真(zhen)空(kong)預(yu)(yu)壓(ya)法作為新(xin)一(yi)代軟(ruan)基(ji)加固方法，以其(qi)工(gong)(gong)期短、施(shi)工(gong)(gong)安全(quan)、無污染環境、費用(yong)低等(deng)(deng)優點而廣(guang)泛應用(yong)于港口、碼頭(tou)、機場、工(gong)(gong)業與民用(yong)建筑(zhu)等(deng)(deng)工(gong)(gong)程(cheng)建設(she)，但理論研究的(de)(de)(de)落(luo)后限制了其(qi)工(gong)(gong)程(cheng)上(shang)的(de)(de)(de)進(jin)一(yi)步推廣(guang)應用(yong)。用(yong)真(zhen)空(kong)預(yu)(yu)壓(ya)加固軟(ruan)土地(di)基(ji)，在(zai)(zai)固結過程(cheng)中(zhong)不僅土體產生垂直沉降，側(ce)向也(ye)會產生向著負壓(ya)源的(de)(de)(de)水(shui)(shui)平(ping)位(wei)移。當在(zai)(zai)真(zhen)空(kong)預(yu)(yu)壓(ya)的(de)(de)(de)影響范圍內有其(qi)他建筑(zhu)設(she)施(shi)時(shi)，使用(yong)該法可能會危及(ji)其(qi)上(shang)部(bu)結構(gou)物(wu)的(de)(de)(de)安全(quan)。真(zhen)空(kong)預(yu)(yu)壓(ya)法施(shi)工(gong)(gong)流程(cheng)如(ru)下(xia)(xia)(xia)：測量放線→鋪(pu)設(she)主(zhu)支濾排(pai)水(shui)(shui)管→鋪(pu)設(she)上(shang)層砂(sha)墊(dian)層→砂(sha)面整平(ping)→鋪(pu)設(she)聚氯乙烯(xi)薄膜(mo)→施(shi)工(gong)(gong)密封(feng)溝→設(she)置(zhi)測量標(biao)志→安裝真(zhen)空(kong)泵→抽真(zhen)空(kong)預(yu)(yu)壓(ya)固結土層。