透水(shui)地坪就是常說(shuo)的(de)透水(shui)路(lu)面,它的(de)結構有多種:
1、具有(you)較小蓄水(shui)能力的透水(shui)路(lu)面
這種透(tou)(tou)水(shui)(shui)路面基層主要(yao)由找平(ping)層、透(tou)(tou)水(shui)(shui)基層構成,透(tou)(tou)水(shui)(shui)基層有很(hen)(hen)大(da)的(de)(de)空隙率,但厚(hou)度不大(da),具有很(hen)(hen)強的(de)(de)透(tou)(tou)水(shui)(shui)能力,適合降雨(yu)量較小、墊層透(tou)(tou)水(shui)(shui)能力很(hen)(hen)強且具有較高的(de)(de)承載力的(de)(de)地域。主要(yao)適用(yong)于(yu)人行道、非(fei)機動車道、廣場(chang)、停車場(chang)、步行街、庭院(yuan)路等場(chang)所(suo)。
2、具(ju)有(you)較(jiao)大蓄水能力(li)的透(tou)水基(ji)層(ceng)的透(tou)水路面
這(zhe)種(zhong)(zhong)基(ji)層(ceng)(ceng)(ceng)一般由找平(ping)層(ceng)(ceng)(ceng)、蓄水(shui)(shui)基(ji)層(ceng)(ceng)(ceng)、土(tu)(tu)工(gong)(gong)織(zhi)物(wu)構(gou)成(cheng),蓄水(shui)(shui)層(ceng)(ceng)(ceng)厚度較(jiao)(jiao)大(da),且空隙率較(jiao)(jiao)小,當降(jiang)(jiang)雨(yu)量(liang)較(jiao)(jiao)大(da)不(bu)能(neng)及時排(pai)(pai)出時,一部分雨(yu)水(shui)(shui)可(ke)以(yi)儲存(cun)在基(ji)層(ceng)(ceng)(ceng)中,避免路面積水(shui)(shui)。這(zhe)種(zhong)(zhong)基(ji)層(ceng)(ceng)(ceng)適合降(jiang)(jiang)雨(yu)量(liang)較(jiao)(jiao)大(da)的情(qing)況(kuang),可(ke)以(yi)邊(bian)蓄水(shui)(shui),邊(bian)排(pai)(pai)水(shui)(shui)。蓄水(shui)(shui)層(ceng)(ceng)(ceng)下(xia)面是土(tu)(tu)工(gong)(gong)織(zhi)物(wu),其(qi)作用是保持(chi)墊(dian)層(ceng)(ceng)(ceng)承(cheng)(cheng)載力。土(tu)(tu)工(gong)(gong)織(zhi)物(wu)大(da)體可(ke)分為(wei)透(tou)水(shui)(shui)型(xing)(xing)土(tu)(tu)工(gong)(gong)網(wang)(wang)格布(bu)和非(fei)透(tou)永型(xing)(xing)防(fang)滲(shen)(shen)土(tu)(tu)工(gong)(gong)布(bu)兩種(zhong)(zhong)。當土(tu)(tu)中含砂量(liang)較(jiao)(jiao)大(da)時,通常稱為(wei)砂土(tu)(tu),有一定的滲(shen)(shen)透(tou)能(neng)力,并且雨(yu)水(shui)(shui)滲(shen)(shen)透(tou)下(xia)去不(bu)會引起較(jiao)(jiao)大(da)的承(cheng)(cheng)載力降(jiang)(jiang)低及污染(ran),這(zhe)時可(ke)以(yi)選用滲(shen)(shen)透(tou)的土(tu)(tu)工(gong)(gong)網(wang)(wang)格布(bu)以(yi)提高承(cheng)(cheng)載力。既需要提高承(cheng)(cheng)載力又要防(fang)止水(shui)(shui)滲(shen)(shen)透(tou)造(zao)成(cheng)污染(ran),應選用非(fei)透(tou)水(shui)(shui)型(xing)(xing)防(fang)滲(shen)(shen)土(tu)(tu)工(gong)(gong)布(bu)。
3、內部具有溢流(liu)結構的透水路(lu)面
(1)墊(dian)層(ceng)(ceng)(ceng)(ceng)可(ke)以滲(shen)透(tou)(tou)(tou)且內部(bu)具有溢(yi)(yi)(yi)(yi)流(liu)(liu)排水(shui)(shui)(shui)(shui)結(jie)構的(de)透(tou)(tou)(tou)水(shui)(shui)(shui)(shui)路面:這種基層(ceng)(ceng)(ceng)(ceng)可(ke)暫時儲(chu)存透(tou)(tou)(tou)過路面的(de)雨水(shui)(shui)(shui)(shui),然(ran)后進一步滲(shen)透(tou)(tou)(tou)。其儲(chu)水(shui)(shui)(shui)(shui)層(ceng)(ceng)(ceng)(ceng)構造(zao)包括找平(ping)層(ceng)(ceng)(ceng)(ceng)、碎石層(ceng)(ceng)(ceng)(ceng)和透(tou)(tou)(tou)水(shui)(shui)(shui)(shui)型土工網格布。當降雨量(liang)較小,土基的(de)滲(shen)透(tou)(tou)(tou)系數很(hen)大,水(shui)(shui)(shui)(shui)可(ke)以直接滲(shen)透(tou)(tou)(tou)到地下而不影響其承載力(li)(不污染地下水(shui)(shui)(shui)(shui)源(yuan)的(de)前提下)。當降雨量(liang)較大時,雨水(shui)(shui)(shui)(shui)充滿整個蓄水(shui)(shui)(shui)(shui)基層(ceng)(ceng)(ceng)(ceng)時,水(shui)(shui)(shui)(shui)位高(gao)于內部(bu)設置的(de)溢(yi)(yi)(yi)(yi)流(liu)(liu)管(guan)管(guan)口(kou),雨水(shui)(shui)(shui)(shui)可(ke)以通過溢(yi)(yi)(yi)(yi)流(liu)(liu)管(guan)排出路外。溢(yi)(yi)(yi)(yi)流(liu)(liu)管(guan)應(ying)沿透(tou)(tou)(tou)水(shui)(shui)(shui)(shui)路面縱向且遠離機動(dong)車道均勻布置,溢(yi)(yi)(yi)(yi)流(liu)(liu)管(guan)的(de)數量(liang)與間距應(ying)根據設計降雨量(liang)、面層(ceng)(ceng)(ceng)(ceng)及墊(dian)層(ceng)(ceng)(ceng)(ceng)的(de)滲(shen)透(tou)(tou)(tou)系數選取(qu)。
(2)墊層(ceng)(ceng)不(bu)能(neng)(neng)滲(shen)透(tou)且內部(bu)具有(you)溢流排水(shui)結構(gou)的透(tou)水(shui)路面:這種基層(ceng)(ceng)可長時(shi)間(jian)儲存(cun)滲(shen)入基層(ceng)(ceng)的雨水(shui),在基層(ceng)(ceng)與(yu)墊層(ceng)(ceng)之間(jian)設置非透(tou)水(shui)型(xing)土工(gong)布,雨水(shui)不(bu)能(neng)(neng)直接滲(shen)透(tou)到地下,而是通過內部(bu)地下管道(dao)排出路外。這種基層(ceng)(ceng)適用于降雨量大、土基滲(shen)透(tou)系數小、墊層(ceng)(ceng)滲(shen)水(shui)后承載力很低(di)、有(you)可能(neng)(neng)造成污染水(shui)源(yuan)的位(wei)置。