大型彎曲彩鋼板屋面鋼結構工程機械施工工藝流程(cheng)及操(cao)作要點
1、工藝流程
建立拱(gong)形(xing)屋面測量控制(zhi)網(wang)及(ji)測量控制(zhi) → 主(zhu)拱(gong)支撐架體設計→ 主(zhu)拱(gong)吊裝(zhuang)及(ji)拱(gong)形(xing)屋面安裝(zhuang) → 卸(xie)荷
2、操作(zuo)要(yao)點
大跨度鋼無(wu)梁拱(gong)拱(gong)形(xing)屋面(mian)安裝同(tong)時涉(she)及分段及吊(diao)機的(de)選擇、施工(gong)測量(liang)定位、支撐架體的(de)設臵、鋼無(wu)梁拱(gong)的(de)吊(diao)裝及拱(gong)形(xing)屋面(mian)安裝、卸荷等多種拱(gong)形(xing)屋面(mian)施工(gong)工(gong)藝，而鋼無(wu)梁拱(gong)的(de)吊(diao)裝及拱(gong)形(xing)屋面(mian)安裝是整個施工(gong)過程的(de)關鍵。
2.1、建立(li)測量控制(zhi)網(wang)及測量控制(zhi)
1.GPS點(dian)的(de)交接及復(fu)(fu)核
根(gen)據(ju)(ju)GPS點(dian)的(de)成(cheng)果(guo)，制(zhi)(zhi)定點(dian)位精度的(de)復(fu)(fu)查(cha)，具體測量步(bu)驟：根(gen)據(ju)(ju)GPS點(dian)的(de)布(bu)局，在(zai)施(shi)(shi)工(gong)區域邊布(bu)設(she)二級控(kong)(kong)(kong)制(zhi)(zhi)網，按閉合導線(xian)的(de)觀測方法，計算出(chu)導線(xian)精度，再根(gen)據(ju)(ju)計算出(chu)的(de)點(dian)位精度，如果(guo)GPS點(dian)的(de)成(cheng)果(guo)符合施(shi)(shi)工(gong)要(yao)(yao)求(qiu)即(ji)可使(shi)用(yong)(yong)，反之(zhi)要(yao)(yao)對(dui)導線(xian)實行(xing)平差(cha)后才可使(shi)用(yong)(yong);對(dui)水(shui)準點(dian)的(de)復(fu)(fu)查(cha)，采用(yong)(yong)國家二級水(shui)準的(de)要(yao)(yao)求(qiu)進行(xing)復(fu)(fu)查(cha)，在(zai)施(shi)(shi)工(gong)區域內(nei)按施(shi)(shi)工(gong)需要(yao)(yao)布(bu)設(she)若干固定的(de)水(shui)準基準點(dian)，對(dui)布(bu)設(she)的(de)水(shui)準點(dian)實行(xing)聯測。
建立施(shi)(shi)工(gong)控(kong)(kong)(kong)制(zhi)(zhi)網(有軸線(xian)控(kong)(kong)(kong)制(zhi)(zhi)樁(zhuang))，形(xing)成(cheng)統一布(bu)局
2.2、施工(gong)中的測量控制
1.主拱跨度(du)(du)大，對(dui)于四個主拱與(yu)地(di)面接觸點的控制精度(du)(du)要求相對(dui)高，在(zai)二級導線的基礎(chu)上(shang)用(yong)極坐標(biao)法放樣(yang)出四個接觸點，建立(li)一矩形(xing)導線閉合(he)環，用(yong)距離、角(jiao)度(du)(du)復核精度(du)(du);
2.主拱(gong)為斜平(ping)面主拱(gong)，在測(ce)量控制上采(cai)用直角(jiao)相(xiang)交觀測(ce)法;
3.主拱采用分段拱形屋面安裝，在二級(ji)控(kong)制基礎上布臵方格網，對(dui)桁架節點進行控(kong)制
4.高程測(ce)(ce)量
依據現場(chang)的已(yi)知水(shui)準點，在施工場(chang)區內測(ce)(ce)設水(shui)準基準點，水(shui)準點的密度(du)應為(wei)100m左右一個，水(shui)準路(lu)線(xian)構成(cheng)附和路(lu)線(xian)，以(yi)便校核，觀測(ce)(ce)精度(du)要(yao)(yao)滿足四等(deng)水(shui)準的要(yao)(yao)求，閉合(he)差要(yao)(yao)小(xiao)于(yu)(L為(wei)線(xian)路(lu)長，以(yi)千米計(ji);n為(wei)測(ce)(ce)站(zhan)數。)
5.變(bian)形(xing)(xing)觀測(ce)
在確(que)認(ren)施工拱(gong)形(xing)(xing)屋(wu)面安裝(zhuang)準確(que)后，以(yi)(yi)拱(gong)形(xing)(xing)屋(wu)面安裝(zhuang)監(jian)測(ce)所(suo)測(ce)定的(de)每個標志點的(de)實際坐標和(he)高程(cheng)作(zuo)為基(ji)準值(zhi)。以(yi)(yi)后每隔(ge)2周按拱(gong)形(xing)(xing)屋(wu)面安裝(zhuang)監(jian)測(ce)時用同精度的(de)觀測(ce)方法(fa)對標志點進行觀測(ce)，計算出坐標和(he)高程(cheng)與基(ji)準值(zhi)進行比較，從而確(que)認(ren)鋼架頂(ding)部的(de)變(bian)形(xing)(xing)情況。直至建筑物封頂(ding)看不見(jian)標志點后，變(bian)形(xing)(xing)觀測(ce)結(jie)束。
2.3 、主拱支撐架(jia)體(ti)設計
1.根(gen)(gen)據鋼無梁拱(gong)結(jie)(jie)構體系(xi)分(fen)(fen)折，并結(jie)(jie)合設(she)(she)計(ji)結(jie)(jie)構的節(jie)點詳圖，首(shou)先(xian)拱(gong)形屋(wu)面(mian)安(an)裝周邊(bian)的鋼柱及鋼柱間的連梁，然(ran)后拱(gong)形屋(wu)面(mian)安(an)裝中(zhong)間拱(gong)和屋(wu)面(mian)梁，在(zai)(zai)主拱(gong)未(wei)能形成三角(jiao)形桁(heng)架(jia)之(zhi)前，整個(ge)屋(wu)面(mian)鋼結(jie)(jie)構的中(zhong)間部(bu)分(fen)(fen)荷(he)載全由中(zhong)間拱(gong)來(lai)支(zhi)撐，所(suo)以首(shou)先(xian)在(zai)(zai)中(zhong)間拱(gong)下(xia)方設(she)(she)臵支(zhi)撐，并根(gen)(gen)據混凝(ning)土柱網(wang)間距在(zai)(zai)中(zhong)間拱(gong)下(xia)方每個(ge)混凝(ning)土柱柱頂設(she)(she)臵承重支(zhi)撐架(jia)。
主拱為主要(yao)受力桿(gan)(gan)件及結構體(ti)系的主支(zhi)撐構件，在(zai)分段(duan)吊裝時自重(zhong)(zhong)必須外加支(zhi)撐體(ti)系來完成，所以(yi)在(zai)主拱的投影弧線(xian)上同(tong)樣根據混凝土結構梁、柱位(wei)(wei)臵(ge)、間距等設臵(ge)底部承重(zhong)(zhong)支(zhi)撐。其(qi)位(wei)(wei)臵(ge)盡量選在(zai)每(mei)兩橫軸中(zhong)間附(fu)近，即在(zai)各(ge)撐桿(gan)(gan)與斜主拱相交點附(fu)近，主拱下各(ge)支(zhi)承架設臵(ge)在(zai)每(mei)兩軸中(zhong)間，既能符合斜主拱承重(zhong)(zhong)定位(wei)(wei)拼裝要(yao)求，也(ye)滿足各(ge)撐桿(gan)(gan)的拱形屋(wu)面安(an)裝施(shi)工。
每個(ge)支(zhi)(zhi)(zhi)承(cheng)(cheng)架(jia)(jia)搭設(she)前，需首先(xian)拱形屋(wu)面(mian)安裝(zhuang)完畢(bi)該跨的屋(wu)梁，并(bing)將(jiang)該處支(zhi)(zhi)(zhi)承(cheng)(cheng)架(jia)(jia)上(shang)(shang)(shang)(shang)部(bu)(bu)臨時采(cai)用(yong)檁條將(jiang)支(zhi)(zhi)(zhi)承(cheng)(cheng)架(jia)(jia)與(yu)屋(wu)梁連接固定(ding)，必要時將(jiang)支(zhi)(zhi)(zhi)承(cheng)(cheng)架(jia)(jia)頂端用(yong)攬(lan)(lan)繩(sheng)(sheng)與(yu)屋(wu)梁上(shang)(shang)(shang)(shang)的檁托(tuo)板(ban)拉(la)牢，以(yi)(yi)確(que)保支(zhi)(zhi)(zhi)承(cheng)(cheng)架(jia)(jia)上(shang)(shang)(shang)(shang)部(bu)(bu)穩(wen)定(ding)性(xing)，同時在支(zhi)(zhi)(zhi)承(cheng)(cheng)架(jia)(jia)屋(wu)梁與(yu)樓面(mian)之間(jian)中(zhong)部(bu)(bu)也用(yong)攬(lan)(lan)繩(sheng)(sheng)與(yu)樓面(mian)錨固板(ban)拉(la)牢固定(ding)，攬(lan)(lan)繩(sheng)(sheng)上(shang)(shang)(shang)(shang)應設(she)有手(shou)拉(la)葫蘆以(yi)(yi)便于調節，并(bing)在支(zhi)(zhi)(zhi)承(cheng)(cheng)架(jia)(jia)下(xia)部(bu)(bu)焊上(shang)(shang)(shang)(shang)?48短鋼管，用(yong)腳手(shou)鋼管將(jiang)支(zhi)(zhi)(zhi)承(cheng)(cheng)架(jia)(jia)下(xia)部(bu)(bu)連結牢固，確(que)保支(zhi)(zhi)(zhi)承(cheng)(cheng)架(jia)(jia)體(ti)的整體(ti)穩(wen)定(ding)性(xing)。
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