許(xu)溝(gou)大橋(qiao)位(wei)于洛三(san)高速公(gong)(gong)路k49+453.37~k49+946.51,三(san)門峽義馬市(shi)近(jin)郊(jiao),該橋(qiao)橋(qiao)孔布置(zhi)自東向西:9×20m+220m+4×20m,全長493.14m。由中(zhong)鐵十一(yi)(yi)局集團第一(yi)(yi)工(gong)程有(you)限公(gong)(gong)司施工(gong)建設。
該橋橋孔(kong)布置(zhi)自東(dong)向(xiang)西:9×20m+220m+4×20m,全長493.14m。主孔(kong)為(wei)等截面(mian)懸鏈線箱形無鉸拱,截面(mian)為(wei)三室箱,拱軸系數m=1.543,凈(jing)跨徑L0=220m,凈(jing)矢高(gao)f0=40m,矢跨比f0/L0=1/5.5。拱上建(jian)筑為(wei)13-17.5m先張預應力混凝(ning)土空心板及(ji)雙柱(zhu)式(shi)排架(jia)立柱(zhu),橋面(mian)連續,柱(zhu)間(jian)設橫向(xiang)聯系。東(dong)西引橋為(wei)20m預應力混凝(ning)土空心板梁,橋面(mian)連續,下部為(wei)雙柱(zhu)式(shi)墩臺,基礎為(wei)鉆孔(kong)灌注(zhu)嵌巖樁(zhuang)。
該橋橋寬(kuan)為24m,分上、下(xia)行,單幅橋寬(kuan)為12m(11+2×0.5m墻(qiang)式護欄)。設計荷載為:汽-超20,掛-120。主拱(gong)(gong)(gong)(gong)拱(gong)(gong)(gong)(gong)座為重(zhong)力(li)式基(ji)礎(chu),置于(yu)樁基(ji)或完整砂巖上。上下(xia)行之間設3cm沉降縫,每個拱(gong)(gong)(gong)(gong)座混(hun)凝土(tu)(tu)量6000m以上,屬大(da)體積混(hun)凝土(tu)(tu),采取基(ji)坑滿(man)注,提高(gao)拱(gong)(gong)(gong)(gong)座背后(hou)土(tu)(tu)抗力(li);主拱(gong)(gong)(gong)(gong)拱(gong)(gong)(gong)(gong)箱采用C50混(hun)凝土(tu)(tu)。上、下(xia)行拱(gong)(gong)(gong)(gong)圈(quan)之間為加強聯結(jie)(jie),設6處聯結(jie)(jie)系。
許(xu)溝(gou)大(da)橋位(wei)于(yu)洛三(san)高速公路k49+453.37~k49+946.51,三(san)門(men)峽義馬市近(jin)郊(jiao),常窯水庫下(xia)(xia)游,跨(kua)越許(xu)溝(gou),溝(gou)中常年無(wu)水。溝(gou)槽內地勢(shi)較(jiao)為平(ping)坦(tan),表層(ceng)(ceng)為亞砂土(tu),下(xia)(xia)層(ceng)(ceng)為卵石(shi)層(ceng)(ceng);兩岸地質(zhi)(zhi)較(jiao)好,表層(ceng)(ceng)有0~3m的沖(chong)積(ji)亞砂土(tu)和卵石(shi)層(ceng)(ceng),下(xia)(xia)層(ceng)(ceng)為泥質(zhi)(zhi)粉砂與粉砂質(zhi)(zhi)泥頁(ye)巖互(hu)層(ceng)(ceng)。該地區最大(da)風力為20m/s,有霜(shuang)期為180~240天。