专属技巧揭秘：让土工膜接头焊接更完美！

1.施工顺序

施工(gong)顺序：基面(mian)清(qing)理平整→铺(pu)设土工(gong)膜(mo)→回(hui)填细砂或铺(pu)油毡过渡层→浇(jiao)筑砼(tong)或填土压实保护层。

2.施工方法

（1）膜(mo)料剪裁。成卷膜(mo)料应根据铺(pu)膜(mo)基槽(cao)断面(mian)(mian)尺寸大小及每段长度剪裁。纵向铺(pu)膜(mo)时(shi)，按基槽(cao)断面(mian)(mian)尺寸计算所需(xu)膜(mo)料的幅(fu)数。横向铺(pu)膜(mo)时(shi)，以铺(pu)设基槽(cao)断面(mian)(mian)的长度为一(yi)幅(fu)。由于膜(mo)料具有一(yi)定的伸(shen)缩性(xing)，并考虑到温(wen)度变化和施(shi)工时(shi)不能拉(la)得太(tai)紧(jin)等

因素，剪裁时，一般应比(bi)基(ji)槽实际轮廓长度长5%。

（2）膜(mo)(mo)(mo)(mo)(mo)(mo)(mo)料铺(pu)设。基(ji)(ji)槽(cao)面开挖(wa)整(zheng)(zheng)平后即铺(pu)上一(yi)(yi)(yi)层(ceng)约8cm厚细砂土(tu)(tu)（建筑物铺(pu)油毡）作过渡层(ceng)，做到基(ji)(ji)面平整(zheng)(zheng)无(wu)凹凸，无(wu)尖(jian)锐物，经验收(shou)合格后进(jin)行(xing)(xing)土(tu)(tu)工(gong)(gong)(gong)(gong)膜(mo)(mo)(mo)(mo)(mo)(mo)(mo)施工(gong)(gong)(gong)(gong)。在清理合格的(de)基(ji)(ji)面基(ji)(ji)槽(cao)上铺(pu)土(tu)(tu)工(gong)(gong)(gong)(gong)膜(mo)(mo)(mo)(mo)(mo)(mo)(mo)，自(zi)渠(qu)(qu)道下游(you)向(xiang)上游(you)，由渠(qu)(qu)道一(yi)(yi)(yi)岸(an)向(xiang)另(ling)一(yi)(yi)(yi)岸(an)铺(pu)设膜(mo)(mo)(mo)(mo)(mo)(mo)(mo)层(ceng)，使膜(mo)(mo)(mo)(mo)(mo)(mo)(mo)料上游(you)一(yi)(yi)(yi)幅(fu)压(ya)下游(you)一(yi)(yi)(yi)幅(fu)，以便在水流(liu)压(ya)力下连接(jie)(jie)(jie)缝(feng)(feng)密合，提高防渗效果(guo)(guo)。处理好大(da)小膜(mo)(mo)(mo)(mo)(mo)(mo)(mo)幅(fu)间的(de)连接(jie)(jie)(jie)缝(feng)(feng)，检查并(bing)粘(zhan)补已铺(pu)膜(mo)(mo)(mo)(mo)(mo)(mo)(mo)层(ceng)的(de)破孔(kong)。土(tu)(tu)工(gong)(gong)(gong)(gong)膜(mo)(mo)(mo)(mo)(mo)(mo)(mo)的(de)连接(jie)(jie)(jie)是施工(gong)(gong)(gong)(gong)的(de)关键工(gong)(gong)(gong)(gong)序，本工(gong)(gong)(gong)(gong)程采用(yong)焊(han)(han)接(jie)(jie)(jie)法连接(jie)(jie)(jie)。土(tu)(tu)工(gong)(gong)(gong)(gong)膜(mo)(mo)(mo)(mo)(mo)(mo)(mo)接(jie)(jie)(jie)头采用(yong)专用(yong)焊(han)(han)接(jie)(jie)(jie)机对(dui)搭接(jie)(jie)(jie)缝(feng)(feng)进(jin)行(xing)(xing)焊(han)(han)接(jie)(jie)(jie)热合处理，焊(han)(han)接(jie)(jie)(jie)时(shi)搭接(jie)(jie)(jie)宽(kuan)度(du)(du)大(da)于20cm，采用(yong)双(shuang)焊(han)(han)缝(feng)(feng)焊(han)(han)接(jie)(jie)(jie)。焊(han)(han)接(jie)(jie)(jie)时(shi)配备一(yi)(yi)(yi)平整(zheng)(zheng)木(mu)板（长度(du)(du)视(shi)需(xu)要而定），先将下层(ceng)膜(mo)(mo)(mo)(mo)(mo)(mo)(mo)料顺(shun)着木(mu)板沿(yan)接(jie)(jie)(jie)缝(feng)(feng)口拉顺(shun)拉齐、铺(pu)平、擦(ca)拭干净，再铺(pu)上层(ceng)接(jie)(jie)(jie)缝(feng)(feng)膜(mo)(mo)(mo)(mo)(mo)(mo)(mo)料，然后用(yong)预(yu)热至规定温度(du)(du)（一(yi)(yi)(yi)般(ban)为160～180℃）的(de)焊(han)(han)接(jie)(jie)(jie)机以约30cm/min的(de)速度(du)(du)沿(yan)木(mu)板面均匀行(xing)(xing)走。焊(han)(han)接(jie)(jie)(jie)宽(kuan)度(du)(du)一(yi)(yi)(yi)般(ban)为5～6cm。粘(zhan)补时(shi)将膜(mo)(mo)(mo)(mo)(mo)(mo)(mo)料铺(pu)在平台上，用(yong)配好的(de)粘(zhan)接(jie)(jie)(jie)剂沿(yan)破孔(kong)周(zhou)边涂匀，应超出破孔(kong)每(mei)边10～20cm，随即将粘(zhan)补膜(mo)(mo)(mo)(mo)(mo)(mo)(mo)对(dui)准破孔(kong)，均匀压(ya)下，使其粘(zhan)接(jie)(jie)(jie)紧密。土(tu)(tu)工(gong)(gong)(gong)(gong)膜(mo)(mo)(mo)(mo)(mo)(mo)(mo)焊(han)(han)接(jie)(jie)(jie)完(wan)毕后开始铺(pu)设，铺(pu)设时(shi)不要拉得(de)太紧，膜(mo)(mo)(mo)(mo)(mo)(mo)(mo)料应留(liu)有小折皱，并(bing)贴(tie)渠(qu)(qu)基(ji)(ji)，以避免(mian)土(tu)(tu)工(gong)(gong)(gong)(gong)膜(mo)(mo)(mo)(mo)(mo)(mo)(mo)伸缩时(shi)接(jie)(jie)(jie)头脱掉(diao)而影响防渗效果(guo)(guo)。

（3）保(bao)护层(ceng)(ceng)(ceng)施(shi)(shi)(shi)工(gong)(gong)(gong)。当膜料铺设完(wan)毕后回填(tian)细砂(sha)（或(huo)铺油毡）作(zuo)过(guo)渡(du)层(ceng)(ceng)(ceng)，再填(tian)土(tu)或(huo)浇(jiao)筑砼(tong)(tong)作(zuo)保(bao)护层(ceng)(ceng)(ceng)。填(tian)筑过(guo)渡(du)层(ceng)(ceng)(ceng)和保(bao)护层(ceng)(ceng)(ceng)的(de)施(shi)(shi)(shi)工(gong)(gong)(gong)速度(du)，应(ying)与铺膜速度(du)配合，避免膜层(ceng)(ceng)(ceng)裸露时间(jian)过(guo)长(zhang)，当天铺膜应(ying)当天填(tian)筑好过(guo)渡(du)层(ceng)(ceng)(ceng)和保(bao)护层(ceng)(ceng)(ceng)。填(tian)筑保(bao)护层(ceng)(ceng)(ceng)的(de)土(tu)料应(ying)不含石块(kuai)、树根(gen)、草根(gen)等杂物(wu)。施(shi)(shi)(shi)工(gong)(gong)(gong)人员应(ying)穿胶底鞋(xie)或(huo)软底鞋(xie)，谨慎(shen)施(shi)(shi)(shi)工(gong)(gong)(gong)。砼(tong)(tong)施(shi)(shi)(shi)工(gong)(gong)(gong)按伸缩缝分块(kuai)跳仓浇(jiao)筑，浇(jiao)完(wan)后要加强养护，以(yi)保(bao)证砼(tong)(tong)强度(du)，防止开裂。