支架預壓沉降觀測分析實施報告

吉安贛江特大橋13#、14#墩三角形掛籃預壓沉降觀測分析總結(jié)報告編制審核審批監(jiān)理工程師中鐵二十二局集團第四工程有限公司

蒙華項目經(jīng)理部

2017年10月23日吉安贛江特大橋13#、14#掛籃預壓沉降觀測分析總結(jié)報告一、 預壓目的為了確保掛籃施工安全，減少掛籃的非彈性變形，獲取彈性變形參數(shù)，得出壓重與掛籃本身的變形關(guān)系，為掛籃施工和線性控制提供掛籃彈性撓度計算的可靠依據(jù)，保證施工質(zhì)量和安全，對掛籃進行加載試驗檢驗，消除整個掛籃的塑性變形，測量出掛籃的彈性變形。二、 預壓方法a、 預壓加載按照加壓荷載的0%、20%、40%、60%、80%、100%、110%進行，布載截面形式應(yīng)模擬梁體荷載分布。加載順序盡可能模擬混凝土澆筑順序。在加載前0%時先進行測量，第一次加載箱梁底板及腹板處，加載至20%，依次40%、60%、80%、100%、，加載至110%，采用1mX1mX0.62m類型混凝土預制塊231塊。具體加載順序詳見荷載布置斷面圖。b、 采用水準儀測量，分別測量加載前讀數(shù)。加載時，按照加壓荷載的0%、20%、40%、60%、80%、100%、110%分級進行，加載完成后觀測記錄，直至最后的平均沉降值＜2mm并滿足24小時以上時方可卸載。然后逐級卸載至100%、80%、60%、40%、20%、0%。待總體沉降量穩(wěn)定后，最后再測量一次卸載后讀數(shù)。c、 在壓載過程中采用水準儀實施全天候跟蹤觀測掛籃的變形情況并作好記錄，待掛籃不再發(fā)生沉降，預壓過程即告結(jié)束。在進行壓載施工中，要邊進行壓載，邊觀測掛籃的變形情況，發(fā)現(xiàn)異常應(yīng)立即停止壓載作業(yè)，及時查找原因，處理正常后再進行壓載。d、 掛籃標高調(diào)整：架體預壓前，掛籃按照設(shè)計標高調(diào)整，通過

預壓，觀測計算得出掛籃彈性變形數(shù)值，調(diào)整梁底標高。梁底標高=設(shè)計梁底標高+掛籃彈性變形值+設(shè)計預拱度。掛籃預制塊縱面布置圖

三、預壓過程表1 跨贛江特大橋13#墩掛籃預壓記錄表序號日期時間施工情況備注12017.10.188:00--8:30加載前22017.10.188:30--9:40加載至20%32017.10.1811:45--14:00加載至40%42017.10.1816:00--17:20加載至60%52017.10.196:30--8:20加載至80%62017.10.1910:20--11:25加載至100%72017.10.1913:00--13:35加載至110%82017.10.2015:35--16:10卸載至100%92017.10.2018:10--18:50卸載至80%102017.10.216:30--7:35卸載至60%112017.10.2110:20--11:25卸載至40%122017.10.2113:00--14:35卸載至20%132017.10.2116:50--18:10卸載至0%

表2 跨贛江特大橋14#墩掛籃預壓記錄表序號日期時間施工情況備注12017.10.1713:00--13:30加載前22017.10.1716:35--17:20加載至20%32017.10.187:00--7:35加載至40%42017.10.1810:00--10:25加載至60%52017.10.1814:00--14:35加載至80%62017.10.1818:15--18:40加載至100%72017.10.198:35--9:16加載至110%82017.10.209:15--9:45卸載至100%92017.10.2013:00--13:32卸載至80%102017.10.2017:20--17:50卸載至60%112017.10.219:40--10:06卸載至40%122017.10.2117:31--17:58卸載至20%132017.10.228:10--8:35卸載至0%四、預壓結(jié)果匯總表1預壓結(jié)果匯總墩號平均彈性變形13#15mm14#13mm五、成果應(yīng)用本次觀測較真實模擬箱梁施工的加載過程,達到了預壓目的，驗證了該掛籃結(jié)構(gòu)的設(shè)計滿足安全和質(zhì)量要求。本次預壓所得數(shù)據(jù)能夠指導施工，預壓結(jié)果合格，滿足規(guī)范及設(shè)計要求.可運用該掛籃進行13#、14#主墩連續(xù)梁現(xiàn)澆施工。根據(jù)設(shè)計圖紙，設(shè)計只提拱了成橋后預拱度，在掛籃施工過程中。還要考慮掛籃變形的因素。因此，施工預拱度為掛籃彈性變形值+設(shè)計預拱度，則：對于已預壓的掛籃，根據(jù)如下公式調(diào)整底模標高：底模頂面標高二梁底設(shè)計標高+設(shè)計預拱度（1.5cm）+彈性變形即13#底膜頂面標高=62.312+0.015+0.015=62.34214#底膜頂面標高=62.312+0.013+0.015=62.340后附表：預壓結(jié)果表格

附件1:沉降觀測點橫斷面示意圖掛籃預壓測點布置圖I左前吊測點A1點DU豳點B6點D12附件2:底版預壓觀測點平面布置圖梁端(小里程墩13中心橋墩1，5，7，2，8，3，9，6，4，10，梁端(大里程)圖113#墩底板和上橫梁預壓觀測點平面布置圖圖214#墩底板和上橫梁預壓觀測點平面布置圖*1MIS*1o9007654321—1987654321成72.599872.608872.627872.634861.981961.988961.601961.628961.653961.6719到S72.599172.607872.626872.633661.981361.987661.601261.628161.653061.6711g72.586872.595872.616872.615861.971961.973961.587961.616961.638961.659972.581872.592872.611872.608861.966961.970961.579961.611961.633961.6519羅嬋6O72.577872.588872.605872.604861.963961.969961.575961.601961.628961.6479嬋00O72.574672.583972.597672.599861.960961.967961.573961.599961.625961.6419羅嬋1OO72.570372.580172.592572.597661.957561.964561.571061.597961.621961.6389O72.570372.580372.592872.597761.957661.964561.570961.597661.621961.637572.570372.580172.592572.597661.957661.964561.570961.597961.621961.637972.572872.581872.595872.599861.959961.966961.573961.598961.623961.639972.575672.584872.599672.603061.961961.968561.576361.602161.627361.643500害W嬋72.578172.587572.603672.606461.963661.970461.578661.605461.630561.6476建6O72.581272.5908|72.607272.609461.965961.971561.581461.608561.634461.6509111小里程端61.927961.927161.914961.909961.904961.899861.896261.896261.896261.898961.902561.906361.909712261.938961.938261.925961.918961.914961.912961.908761.908761.908761.910961.913561.916161.918713361.920961.920061.901961.895961.888961.884961.882461.882661.882461.884961.888761.892561.896314461.917961.917961.901961.895961.890961.890961.886561.886761.886561.888961.891961.894561.897915561.997961.996861.980961.977961.975961.972761.968961.968961.968961.970961.973561.976361.978716661.988961.988261.976961.971961.969961.967561.964861.964661.964761.966961.968761.970761.972617772.642872.642272.627872.619872.612872.609672.606472.606472.606472.609872.613672.617672.621218872.646872.646072.633872.629872.621872.613872.610472.610572.610372.612872.615872.618672.621819972.632872.632172.614872.608872.603872.599872.597572.597472.597372.599872.603472.607272.6104201072.624872.624072.610872.597872.592872.589772.581672.586372.586572.588872.592672.596672.6006表2跨贛江特大橋14#墩掛籃預壓沉降觀測數(shù)據(jù)記錄序號編號布點位置加荷載'人刖荷載20%荷載40%荷載60%荷載80%荷載100%荷載110%卸載100%卸載80%卸載60%卸載40%0小時12小時24小時11，大里程端41.28141.27541.27341.27041.27041.26541.26341.26341.26241.26441.27141.27141.27122，41.29541.29041.28741.28241.28241.27941.27841.27741.27641.27941.28241.28241.28833，41.29441.28941.28641.28241.28041.27941.27741.27741.27641.27841.27941.28041.28444，41.23841.23541.23241.22641.22441.22241.22141.22141.22141.22141.22241.22341.22355，41.25841.25441.25141.24741.24441.24441.23541.23441.23441.23541.24241.24241.24366，41.26941.26241.26041.25841.25441.25241.24641.24641.24541.24641.24641.24241.25277，51.43551.43151.42751.42351.41951.41251.40851.40751.40651.40951.41151.41351.41588，51.54751.54251.53751.53151.52751.52151.51851.51751.51751.51851.51951.52051.52299，51.39751.39451.38951.38451.38151.37851.37651.37651.37551.37751.37951.38151.3841010，51.62751.62251.61951.61651.61251.61051.60951.60951.60951.60951.61051.61151.613

111小里程端61.38661.38161.37761.37261.36761.36461.36261.36161.36061.36361.36561.36961.37112261.36161.34861.34761.34561.34361.34261.33961.33861.33761.34061.34161.34361.34513361.38461.38261.38061.37761.37561.37361.37161.37061.36961.37161.37261.37561.37514461.41761.41061.40761.40361.39861.39661.39461.39361.39261.39661.39861.40161.40415561.35861.35361.34961.34661.34361.33961.33761.33761.33761.34061.34261.34561.34816661.37361.37061.36561.36261.35961.35561.35261.35161.35161.35461.35861.36161.36317771.34771.34371.34071.33671.33271.32871.32771.32671.32671.32971.33071.33571.33718871.29471.29171.28771.28271.27971.27671.27571.27571.27471.27771.27971.28271.28519971.26871.262