这项方案竟让防渗与经济双赢，方案 3 凭啥爆火？

根据前面(mian)对现状大坝(ba)(ba)(ba)(ba)的(de)渗(shen)(shen)(shen)(shen)(shen)(shen)流及稳(wen)定(ding)(ding)计(ji)算结果显示(shi),经(jing)计(ji)算坝(ba)(ba)(ba)(ba)体(ti)浸润线符合(he)要(yao)(yao)求(qiu),出逸(yi)点在背(bei)水(shui)(shui)(shui)坡坡脚棱(leng)体(ti)位置,大坝(ba)(ba)(ba)(ba)坝(ba)(ba)(ba)(ba)坡稳(wen)定(ding)(ding),满足规(gui)范(fan)要(yao)(yao)求(qiu)。考虑到大坝(ba)(ba)(ba)(ba)渗(shen)(shen)(shen)(shen)(shen)(shen)透(tou)系(xi)数(shu)、天(tian)然(ran)含水(shui)(shui)(shui)率(lv)和(he)孔隙(xi)率(lv)不合(he)格,大坝(ba)(ba)(ba)(ba)整(zheng)(zheng)体(ti)压(ya)实度(du)不满足规(gui)范(fan)要(yao)(yao)求(qiu),坝(ba)(ba)(ba)(ba)体(ti)填土(tu)(tu)整(zheng)(zheng)体(ti)呈中等透(tou)水(shui)(shui)(shui)性,有(you)发生(sheng)渗(shen)(shen)(shen)(shen)(shen)(shen)漏的(de)可能性,故对其进(jin)行防(fang)(fang)(fang)(fang)渗(shen)(shen)(shen)(shen)(shen)(shen)处(chu)理。对于土(tu)(tu)石坝(ba)(ba)(ba)(ba)的(de)渗(shen)(shen)(shen)(shen)(shen)(shen)漏处(chu)理,总的(de)原则是“上(shang)堵下排(pai)”。上(shang)堵的(de)措施有(you)垂(chui)直(zhi)防(fang)(fang)(fang)(fang)渗(shen)(shen)(shen)(shen)(shen)(shen)和(he)水(shui)(shui)(shui)平(ping)防(fang)(fang)(fang)(fang)渗(shen)(shen)(shen)(shen)(shen)(shen)。垂(chui)直(zhi)防(fang)(fang)(fang)(fang)渗(shen)(shen)(shen)(shen)(shen)(shen)常见的(de)有(you)混凝土(tu)(tu)防(fang)(fang)(fang)(fang)渗(shen)(shen)(shen)(shen)(shen)(shen)墙(qiang)、高压(ya)喷射灌(guan)浆防(fang)(fang)(fang)(fang)渗(shen)(shen)(shen)(shen)(shen)(shen)、劈裂灌(guan)浆防(fang)(fang)(fang)(fang)渗(shen)(shen)(shen)(shen)(shen)(shen)、钻(zuan)探灌(guan)浆防(fang)(fang)(fang)(fang)渗(shen)(shen)(shen)(shen)(shen)(shen)、粘土(tu)(tu)斜墙(qiang)防(fang)(fang)(fang)(fang)渗(shen)(shen)(shen)(shen)(shen)(shen)、土(tu)(tu)工(gong)膜(mo)防(fang)(fang)(fang)(fang)渗(shen)(shen)(shen)(shen)(shen)(shen)等。水(shui)(shui)(shui)平(ping)防(fang)(fang)(fang)(fang)渗(shen)(shen)(shen)(shen)(shen)(shen)常见有(you)黏土(tu)(tu)铺(pu)盖。垂(chui)直(zhi)防(fang)(fang)(fang)(fang)渗(shen)(shen)(shen)(shen)(shen)(shen)处(chu)理可以比较有(you)效的(de)解决坝(ba)(ba)(ba)(ba)体(ti)渗(shen)(shen)(shen)(shen)(shen)(shen)漏问(wen)题而水(shui)(shui)(shui)平(ping)防(fang)(fang)(fang)(fang)渗(shen)(shen)(shen)(shen)(shen)(shen)处(chu)理则必(bi)须结合(he)下游排(pai)水(shui)(shui)(shui)减(jian)压(ya)导(dao)渗(shen)(shen)(shen)(shen)(shen)(shen)措施,虽(sui)可保证坝(ba)(ba)(ba)(ba)体(ti)渗(shen)(shen)(shen)(shen)(shen)(shen)透(tou)稳(wen)定(ding)(ding),但(dan)仍有(you)一(yi)定(ding)(ding)的(de)渗(shen)(shen)(shen)(shen)(shen)(shen)漏损失。

方案(an)(an)1工(gong)程(cheng)造(zao)价(jia)最高,防渗(shen)效(xiao)果可靠度最高；方案(an)(an)2工(gong)程(cheng)造(zao)价(jia)介于(yu)方案(an)(an)1和(he)方案(an)(an)3之间,防渗(shen)效(xiao)果三者中较低；方案(an)(an)3工(gong)程(cheng)造(zao)价(jia)最低,防渗(shen)效(xiao)果较好。

大坝渗(shen)(shen)(shen)(shen)流稳定计(ji)算(suan)水库各(ge)水位工况浸润(run)线较(jiao)为合理(li),且出逸点均在背水坡(po)坡(po)脚棱(leng)体位置。据现场实(shi)测大坝渗(shen)(shen)(shen)(shen)流量水堰数(shu)据,坝体渗(shen)(shen)(shen)(shen)流量偏大,有发生(sheng)渗(shen)(shen)(shen)(shen)漏的可能性。结合现场坝体填筑(zhu)料情(qing)况,本(ben)(ben)工程坝体土料渗(shen)(shen)(shen)(shen)透系(xi)数(shu)为6.48×10-4cm/s, 相比规范要求(qiu)坝体填土渗(shen)(shen)(shen)(shen)透系(xi)数(shu)要求(qiu)值（1×10-4cm/s）稍(shao)大。 且本(ben)(ben)次除险加固需对原干砌石(shi)迎水坡(po)拆除,新建砼护坡(po),防(fang)渗(shen)(shen)(shen)(shen)土工膜可与(yu)各(ge)建筑(zhu)物有良好搭(da)接。综合经(jing)济(ji)角度(du)及防(fang)渗(shen)(shen)(shen)(shen)效果(guo)考虑,本(ben)(ben)次的处理(li)方案(an)推荐选用(yong)防(fang)渗(shen)(shen)(shen)(shen)效果(guo)较(jiao)好,投资(zi)最优的防(fang)渗(shen)(shen)(shen)(shen)土工膜方案(an),即方案(an)3。