許(xu)溝大橋位于(yu)洛(luo)三高速(su)公路k49+453.37~k49+946.51,三門峽(xia)義馬(ma)市近(jin)郊,該橋橋孔布置自東向西:9×20m+220m+4×20m,全長(chang)493.14m。由(you)中鐵十一局集團第一工程有限公司施工建設。
該橋(qiao)橋(qiao)孔(kong)布置自東向西:9×20m+220m+4×20m,全長493.14m。主孔(kong)為等截面懸鏈(lian)線箱形無鉸拱(gong)(gong),截面為三室(shi)箱,拱(gong)(gong)軸系數(shu)m=1.543,凈跨(kua)徑L0=220m,凈矢高(gao)f0=40m,矢跨(kua)比(bi)f0/L0=1/5.5。拱(gong)(gong)上建筑(zhu)為13-17.5m先(xian)張預(yu)應力混(hun)凝土空(kong)心板(ban)及雙柱式(shi)排(pai)架立柱,橋(qiao)面連續(xu),柱間(jian)設(she)橫向聯系。東西引橋(qiao)為20m預(yu)應力混(hun)凝土空(kong)心板(ban)梁,橋(qiao)面連續(xu),下部為雙柱式(shi)墩臺,基(ji)礎(chu)為鉆孔(kong)灌注嵌(qian)巖樁。
該(gai)橋橋寬為(wei)24m,分上、下行,單(dan)幅橋寬為(wei)12m(11+2×0.5m墻式(shi)護欄(lan))。設計(ji)荷載(zai)為(wei):汽-超20,掛-120。主(zhu)拱(gong)(gong)拱(gong)(gong)座為(wei)重(zhong)力式(shi)基礎,置(zhi)于樁(zhuang)基或完整砂巖上。上下行之間(jian)設3cm沉降縫,每個拱(gong)(gong)座混凝土量6000m以上,屬大體積混凝土,采取(qu)基坑(keng)滿注,提高拱(gong)(gong)座背后(hou)土抗(kang)力;主(zhu)拱(gong)(gong)拱(gong)(gong)箱(xiang)采用C50混凝土。上、下行拱(gong)(gong)圈(quan)之間(jian)為(wei)加強(qiang)聯結(jie),設6處聯結(jie)系。
許溝大(da)(da)橋(qiao)位于洛三高速公路(lu)k49+453.37~k49+946.51,三門峽義(yi)馬市近(jin)郊(jiao),常窯水庫下游,跨越許溝,溝中常年無水。溝槽內地(di)勢(shi)較(jiao)為(wei)(wei)(wei)(wei)平坦,表(biao)層(ceng)為(wei)(wei)(wei)(wei)亞砂(sha)土,下層(ceng)為(wei)(wei)(wei)(wei)卵(luan)石(shi)層(ceng);兩岸地(di)質較(jiao)好(hao),表(biao)層(ceng)有(you)0~3m的沖積亞砂(sha)土和卵(luan)石(shi)層(ceng),下層(ceng)為(wei)(wei)(wei)(wei)泥質粉砂(sha)與粉砂(sha)質泥頁巖互層(ceng)。該地(di)區最大(da)(da)風力為(wei)(wei)(wei)(wei)20m/s,有(you)霜期為(wei)(wei)(wei)(wei)180~240天。