调节池池底防渗施工工序及碾压方法

调节(jie)池(chi)(chi)池(chi)(chi)底(di)防(fang)渗主要施(shi)工(gong)内容(rong)包(bao)括：池(chi)(chi)区土(tu)方开挖(wa)、围封回填、改(gai)性(xing)砂质(zhi)粉土(tu)防(fang)渗层、土(tu)工(gong)布铺设(she)、HDPE膜(mo)铺设(she)、原土(tu)回填、生态连(lian)锁砌块安(an)装。

调(diao)节池池底防(fang)渗施(shi)工工序如下：基底处(chu)理→1m厚改性砂质粉土(tu)防(fang)渗层(ceng)(ceng)摊铺(pu)(pu)碾压→底层(ceng)(ceng)长丝无(wu)纺土(tu)工布(bu)(bu)铺(pu)(pu)设→HDPE膜铺(pu)(pu)设焊接→上层(ceng)(ceng)长丝无(wu)纺土(tu)工布(bu)(bu)铺(pu)(pu)设→0.8m厚中细砂保护层(ceng)(ceng)摊铺(pu)(pu)碾压→护底生态联(lian)锁砌(qi)块铺(pu)(pu)砌(qi)调(diao)节池池底防(fang)渗施(shi)工需土(tu)方开挖,机械开挖至(zhi)距基底高程20cm时,为(wei)避免扰动原基采用人工清基。开完(wan)至(zhi)设计(ji)高程后,经推土(tu)机整平,控(kong)制高程高于设计(ji)开挖底高程50mm左右,使用22T振(zhen)动碾碾压,压实后无(wu)粘(zhan)性土(tu)相对密度(du)不(bu)低于0.65,粘(zhan)性土(tu)压实度(du)不(bu)低于94%,地基承(cheng)载力不(bu)小(xiao)于120kPa。

根据设计(ji)要求,部分区域需采用改性中细砂回填,待改性中细砂回填至调节(jie)池池底(di)防渗施工高程后,进行压实度检(jian)验,地(di)基承载力不小于200kPa。

改(gai)(gai)性(xing)土(tu)(tu)(tu)(tu)拌(ban)和采(cai)用(yong)厂(chang)拌(ban)法。用(yong)于拌(ban)制改(gai)(gai)性(xing)土(tu)(tu)(tu)(tu)的(de)土(tu)(tu)(tu)(tu)料为本工(gong)(gong)(gong)程(cheng)开(kai)挖土(tu)(tu)(tu)(tu)方中经检测合(he)格的(de)砂质(zhi)粉(fen)土(tu)(tu)(tu)(tu),采(cai)用(yong)WCB800型改(gai)(gai)性(xing)土(tu)(tu)(tu)(tu)拌(ban)合(he)系统(tong)将砂质(zhi)粉(fen)土(tu)(tu)(tu)(tu)与42.5硅酸盐水泥拌(ban)合(he)均匀,不合(he)格的(de)改(gai)(gai)性(xing)土(tu)(tu)(tu)(tu)半制品(pin)不得用(yong)于工(gong)(gong)(gong)程(cheng)填(tian)筑(zhu)施(shi)工(gong)(gong)(gong)。拌(ban)合(he)完成的(de)改(gai)(gai)性(xing)土(tu)(tu)(tu)(tu),及时(shi)运至(zhi)摊铺现场,以保(bao)证(zheng)改(gai)(gai)性(xing)土(tu)(tu)(tu)(tu)的(de)性(xing)能。改(gai)(gai)性(xing)土(tu)(tu)(tu)(tu)采(cai)用(yong)密(mi)封自卸车运输至(zhi)填(tian)筑(zhu)工(gong)(gong)(gong)作面,防止遗(yi)撒、扬尘,并减少(shao)运输环(huan)节含水量损失。

改性土填筑由基坑最低处开始填筑,由低到高分层分区域水平铺筑、整平、碾压施工。改性土的铺设在基础处理达到设计要求的压实度后进行。拌合合格的(de)(de)改性土料(liao)用(yong)自卸(xie)汽车运输至填筑(zhu)作(zuo)业面(mian),采用(yong)“进占(zhan)法”进行卸(xie)料(liao),用(yong)推(tui)土机(ji)将土料(liao)推(tui)平(ping),推(tui)平(ping)厚(hou)(hou)度保持(chi)在碾压试验确定的(de)(de)虚铺厚(hou)(hou)度（±2cm）。

为保证(zheng)改性(xing)土的性(xing)能,填筑完(wan)一(yi)个碾(nian)(nian)压(ya)(ya)(ya)区域后(hou),立即进行碾(nian)(nian)压(ya)(ya)(ya)。碾(nian)(nian)压(ya)(ya)(ya)采用(yong)(yong)22t平(ping)面(mian)(mian)振动碾(nian)(nian)碾(nian)(nian)压(ya)(ya)(ya),碾(nian)(nian)压(ya)(ya)(ya)速度控(kong)制在2km/h范围内,采用(yong)(yong)前进振动后(hou)退静压(ya)(ya)(ya)的碾(nian)(nian)压(ya)(ya)(ya)方式。具体(ti)碾(nian)(nian)压(ya)(ya)(ya)方法及各项(xiang)碾(nian)(nian)压(ya)(ya)(ya)参数(shu)均(jun)按照碾(nian)(nian)压(ya)(ya)(ya)试验(yan)所得参数(shu)控(kong)制。碾(nian)(nian)压(ya)(ya)(ya)层间需根据天气和层面(mian)(mian)干燥情况(kuang),洒水湿润(run)。碾(nian)(nian)压(ya)(ya)(ya)作业要做到(dao)无(wu)(wu)偏压(ya)(ya)(ya)、无(wu)(wu)死(si)角、无(wu)(wu)松(song)散等现象。

易(yi)漏(lou)压(ya)(ya)或机(ji)械碾压(ya)(ya)不(bu)到(dao)的(de)(de)区域,由人工采用蛙夯(hang)或冲击夯(hang)等小型设(she)备夯(hang)实(shi),夯(hang)迹(ji)双向(xiang)套压(ya)(ya),夯(hang)压(ya)(ya)夯(hang)1/3,行压(ya)(ya)行1/3,夯(hang)夯(hang)相(xiang)连,不(bu)漏(lou)夯(hang)。碾压(ya)(ya)结束后(hou),用环刀法取样检测(ce)压(ya)(ya)实(shi)度,符合设(she)计要求后(hou)方(fang)可进行下一层的(de)(de)填筑。