透(tou)水(shui)地(di)坪就是(shi)常(chang)說的(de)透(tou)水(shui)路面,它的(de)結(jie)構(gou)有(you)多(duo)種:
1、具有較小蓄水能力的透水路(lu)面(mian)
這種透(tou)水(shui)路面基層主(zhu)要(yao)由找平層、透(tou)水(shui)基層構成,透(tou)水(shui)基層有很(hen)大(da)(da)的空隙率,但(dan)厚度(du)不大(da)(da),具有很(hen)強(qiang)(qiang)的透(tou)水(shui)能力,適合降雨(yu)量較(jiao)(jiao)小、墊層透(tou)水(shui)能力很(hen)強(qiang)(qiang)且具有較(jiao)(jiao)高(gao)的承(cheng)載力的地域。主(zhu)要(yao)適用于(yu)人行道、非機動(dong)車道、廣場、停車場、步(bu)行街、庭院路等場所。
2、具有較大蓄水能力的透(tou)水基層(ceng)的透(tou)水路面
這種基(ji)層(ceng)(ceng)(ceng)(ceng)一(yi)般由(you)找平(ping)層(ceng)(ceng)(ceng)(ceng)、蓄水(shui)(shui)(shui)基(ji)層(ceng)(ceng)(ceng)(ceng)、土(tu)(tu)工(gong)(gong)(gong)織(zhi)物(wu)構(gou)成,蓄水(shui)(shui)(shui)層(ceng)(ceng)(ceng)(ceng)厚度較(jiao)大,且空(kong)隙率較(jiao)小,當(dang)降雨量(liang)較(jiao)大不能及(ji)時排(pai)出時,一(yi)部分雨水(shui)(shui)(shui)可(ke)(ke)(ke)以(yi)儲存在基(ji)層(ceng)(ceng)(ceng)(ceng)中,避(bi)免(mian)路面積水(shui)(shui)(shui)。這種基(ji)層(ceng)(ceng)(ceng)(ceng)適合降雨量(liang)較(jiao)大的(de)(de)情況,可(ke)(ke)(ke)以(yi)邊(bian)蓄水(shui)(shui)(shui),邊(bian)排(pai)水(shui)(shui)(shui)。蓄水(shui)(shui)(shui)層(ceng)(ceng)(ceng)(ceng)下(xia)面是土(tu)(tu)工(gong)(gong)(gong)織(zhi)物(wu),其作用(yong)(yong)是保持墊層(ceng)(ceng)(ceng)(ceng)承(cheng)載力(li)。土(tu)(tu)工(gong)(gong)(gong)織(zhi)物(wu)大體可(ke)(ke)(ke)分為透(tou)水(shui)(shui)(shui)型(xing)土(tu)(tu)工(gong)(gong)(gong)網格布和(he)非透(tou)永型(xing)防(fang)滲(shen)(shen)土(tu)(tu)工(gong)(gong)(gong)布兩種。當(dang)土(tu)(tu)中含(han)砂(sha)量(liang)較(jiao)大時,通常稱為砂(sha)土(tu)(tu),有(you)一(yi)定(ding)的(de)(de)滲(shen)(shen)透(tou)能力(li),并且雨水(shui)(shui)(shui)滲(shen)(shen)透(tou)下(xia)去(qu)不會(hui)引起較(jiao)大的(de)(de)承(cheng)載力(li)降低及(ji)污染,這時可(ke)(ke)(ke)以(yi)選用(yong)(yong)滲(shen)(shen)透(tou)的(de)(de)土(tu)(tu)工(gong)(gong)(gong)網格布以(yi)提(ti)高(gao)承(cheng)載力(li)。既需(xu)要提(ti)高(gao)承(cheng)載力(li)又要防(fang)止(zhi)水(shui)(shui)(shui)滲(shen)(shen)透(tou)造成污染,應選用(yong)(yong)非透(tou)水(shui)(shui)(shui)型(xing)防(fang)滲(shen)(shen)土(tu)(tu)工(gong)(gong)(gong)布。
3、內部具(ju)有溢(yi)流結構的透水(shui)路(lu)面
(1)墊層(ceng)(ceng)(ceng)(ceng)(ceng)可以(yi)滲(shen)透(tou)(tou)(tou)且內(nei)部(bu)具有溢(yi)流(liu)(liu)排(pai)水(shui)(shui)(shui)(shui)結構(gou)的(de)(de)透(tou)(tou)(tou)水(shui)(shui)(shui)(shui)路(lu)面:這種(zhong)基(ji)層(ceng)(ceng)(ceng)(ceng)(ceng)可暫時(shi)儲(chu)存透(tou)(tou)(tou)過(guo)路(lu)面的(de)(de)雨(yu)水(shui)(shui)(shui)(shui),然(ran)后進一(yi)步滲(shen)透(tou)(tou)(tou)。其儲(chu)水(shui)(shui)(shui)(shui)層(ceng)(ceng)(ceng)(ceng)(ceng)構(gou)造包(bao)括(kuo)找平層(ceng)(ceng)(ceng)(ceng)(ceng)、碎石(shi)層(ceng)(ceng)(ceng)(ceng)(ceng)和(he)透(tou)(tou)(tou)水(shui)(shui)(shui)(shui)型土(tu)(tu)工網格布。當(dang)降(jiang)雨(yu)量較(jiao)小,土(tu)(tu)基(ji)的(de)(de)滲(shen)透(tou)(tou)(tou)系數(shu)很(hen)大,水(shui)(shui)(shui)(shui)可以(yi)直接滲(shen)透(tou)(tou)(tou)到地(di)下而不影響其承(cheng)載力(不污染地(di)下水(shui)(shui)(shui)(shui)源的(de)(de)前(qian)提(ti)下)。當(dang)降(jiang)雨(yu)量較(jiao)大時(shi),雨(yu)水(shui)(shui)(shui)(shui)充滿整個蓄水(shui)(shui)(shui)(shui)基(ji)層(ceng)(ceng)(ceng)(ceng)(ceng)時(shi),水(shui)(shui)(shui)(shui)位高于內(nei)部(bu)設置(zhi)的(de)(de)溢(yi)流(liu)(liu)管管口,雨(yu)水(shui)(shui)(shui)(shui)可以(yi)通過(guo)溢(yi)流(liu)(liu)管排(pai)出路(lu)外。溢(yi)流(liu)(liu)管應沿透(tou)(tou)(tou)水(shui)(shui)(shui)(shui)路(lu)面縱向且遠離機(ji)動車道均勻布置(zhi),溢(yi)流(liu)(liu)管的(de)(de)數(shu)量與間距應根(gen)據設計降(jiang)雨(yu)量、面層(ceng)(ceng)(ceng)(ceng)(ceng)及(ji)墊層(ceng)(ceng)(ceng)(ceng)(ceng)的(de)(de)滲(shen)透(tou)(tou)(tou)系數(shu)選取。
(2)墊層不能滲透且內(nei)部具(ju)有(you)(you)溢流(liu)排水(shui)(shui)結構的(de)透水(shui)(shui)路(lu)面(mian):這(zhe)種基(ji)層可(ke)(ke)長時間儲(chu)存滲入基(ji)層的(de)雨(yu)水(shui)(shui),在基(ji)層與(yu)墊層之間設置非(fei)透水(shui)(shui)型土(tu)工布(bu),雨(yu)水(shui)(shui)不能直接滲透到地下,而是通過內(nei)部地下管道(dao)排出路(lu)外。這(zhe)種基(ji)層適用(yong)于降雨(yu)量大(da)、土(tu)基(ji)滲透系數小、墊層滲水(shui)(shui)后承載力很低、有(you)(you)可(ke)(ke)能造成污(wu)染水(shui)(shui)源(yuan)的(de)位置。