真空預壓施工

真(zhen)(zhen)空(kong)預壓(ya)(ya)(ya)(ya)法(fa)就是在需(xu)要(yao)加(jia)固(gu)(gu)的(de)(de)軟基中(zhong)(zhong)插(cha)入豎向(xiang)(xiang)排(pai)水(shui)(shui)通(tong)(tong)道(dao)（如(ru)(ru)砂井、袋裝砂井或塑(su)料排(pai)水(shui)(shui)板(ban)等），然后在地(di)面鋪(pu)設(she)一(yi)(yi)(yi)層(ceng)(ceng)(ceng)砂墊(dian)層(ceng)(ceng)(ceng)，再在其(qi)(qi)上覆蓋一(yi)(yi)(yi)層(ceng)(ceng)(ceng)不(bu)透氣(qi)的(de)(de)薄(bo)膜(mo)。在膜(mo)下抽真(zhen)(zhen)空(kong)形成負(fu)壓(ya)(ya)(ya)(ya)（相對(dui)大氣(qi)壓(ya)(ya)(ya)(ya)而(er)言)），負(fu)壓(ya)(ya)(ya)(ya)沿豎向(xiang)(xiang)排(pai)水(shui)(shui)通(tong)(tong)道(dao)向(xiang)(xiang)下傳遞 土體(ti)與(yu)豎向(xiang)(xiang)排(pai)水(shui)(shui)通(tong)(tong)道(dao)的(de)(de)不(bu)等壓(ya)(ya)(ya)(ya)狀態又(you)使(shi)負(fu)壓(ya)(ya)(ya)(ya)向(xiang)(xiang)土體(ti)中(zhong)(zhong)傳遞，在負(fu)壓(ya)(ya)(ya)(ya)作(zuo)用(yong)(yong)下，孔隙水(shui)(shui)逐(zhu)漸滲流到豎向(xiang)(xiang)排(pai)水(shui)(shui)通(tong)(tong)道(dao)中(zhong)(zhong)而(er)達到土體(ti)排(pai)水(shui)(shui)固(gu)(gu)結(jie)、強(qiang)度增長(chang)的(de)(de)效果。真(zhen)(zhen)空(kong)預壓(ya)(ya)(ya)(ya)法(fa)作(zuo)為新一(yi)(yi)(yi)代軟基加(jia)固(gu)(gu)方法(fa)，以(yi)其(qi)(qi)工(gong)期短、施工(gong)安(an)全、無(wu)污染環境、費用(yong)(yong)低等優點而(er)廣(guang)泛應用(yong)(yong)于港口(kou)、碼頭、機(ji)場、工(gong)業與(yu)民用(yong)(yong)建(jian)筑(zhu)等工(gong)程(cheng)建(jian)設(she)，但理論研究的(de)(de)落(luo)后限(xian)制了其(qi)(qi)工(gong)程(cheng)上的(de)(de)進(jin)一(yi)(yi)(yi)步推(tui)廣(guang)應用(yong)(yong)。用(yong)(yong)真(zhen)(zhen)空(kong)預壓(ya)(ya)(ya)(ya)加(jia)固(gu)(gu)軟土地(di)基，在固(gu)(gu)結(jie)過(guo)程(cheng)中(zhong)(zhong)不(bu)僅土體(ti)產生垂(chui)直沉降，側向(xiang)(xiang)也會(hui)產生向(xiang)(xiang)著負(fu)壓(ya)(ya)(ya)(ya)源(yuan)的(de)(de)水(shui)(shui)平(ping)位(wei)移。當在真(zhen)(zhen)空(kong)預壓(ya)(ya)(ya)(ya)的(de)(de)影(ying)響范圍內(nei)有其(qi)(qi)他建(jian)筑(zhu)設(she)施時，使(shi)用(yong)(yong)該法(fa)可能會(hui)危及其(qi)(qi)上部結(jie)構物的(de)(de)安(an)全。真(zhen)(zhen)空(kong)預壓(ya)(ya)(ya)(ya)法(fa)施工(gong)流程(cheng)如(ru)(ru)下：測量(liang)放線→鋪(pu)設(she)主支濾排(pai)水(shui)(shui)管→鋪(pu)設(she)上層(ceng)(ceng)(ceng)砂墊(dian)層(ceng)(ceng)(ceng)→砂面整平(ping)→鋪(pu)設(she)聚氯乙烯薄(bo)膜(mo)→施工(gong)密封溝→設(she)置(zhi)測量(liang)標志→安(an)裝真(zhen)(zhen)空(kong)泵→抽真(zhen)(zhen)空(kong)預壓(ya)(ya)(ya)(ya)固(gu)(gu)結(jie)土層(ceng)(ceng)(ceng)。