支架預(yù)壓沉降觀測(cè)分析實(shí)施報(bào)告

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

蒙華項(xiàng)目經(jīng)理部

2017年10月23日吉安贛江特大橋13#、14#掛籃預(yù)壓沉降觀測(cè)分析總結(jié)報(bào)告一、 預(yù)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(jì)算的可靠依據(jù)，保證施工質(zhì)量和安全，對(duì)掛籃進(jìn)行加載試驗(yàn)檢驗(yàn)，消除整個(gè)掛籃的塑性變形，測(cè)量出掛籃的彈性變形。二、 預(yù)壓方法a、 預(yù)壓加載按照加壓荷載的0%、20%、40%、60%、80%、100%、110%進(jìn)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(shí)先進(jìn)行測(cè)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(lèi)型混凝土預(yù)制塊231塊。具體加載順序詳見(jiàn)荷載布置斷面圖。b、 采用水準(zhǔn)儀測(cè)量，分別測(cè)量加載前讀數(shù)。加載時(shí)，按照加壓荷載的0%、20%、40%、60%、80%、100%、110%分級(jí)進(jìn)行，加載完成后觀測(cè)記錄，直至最后的平均沉降值＜2mm并滿足24小時(shí)以上時(shí)方可卸載。然后逐級(jí)卸載至100%、80%、60%、40%、20%、0%。待總體沉降量穩(wěn)定后，最后再測(cè)量一次卸載后讀數(shù)。c、 在壓載過(guò)程中采用水準(zhǔn)儀實(shí)施全天候跟蹤觀測(cè)掛籃的變形情況并作好記錄，待掛籃不再發(fā)生沉降，預(yù)壓過(guò)程即告結(jié)束。在進(jìn)行壓載施工中，要邊進(jìn)行壓載，邊觀測(cè)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(shí)查找原因，處理正常后再進(jìn)行壓載。d、 掛籃標(biāo)高調(diào)整：架體預(yù)壓前，掛籃按照設(shè)計(jì)標(biāo)高調(diào)整，通過(guò)

預(yù)壓，觀測(cè)計(jì)算得出掛籃彈性變形數(shù)值，調(diào)整梁底標(biāo)高。梁底標(biāo)高=設(shè)計(jì)梁底標(biāo)高+掛籃彈性變形值+設(shè)計(jì)預(yù)拱度。掛籃預(yù)制塊縱面布置圖

三、預(yù)壓過(guò)程表1 跨贛江特大橋13#墩掛籃預(yù)壓記錄表序號(hào)日期時(shí)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(yù)壓記錄表序號(hào)日期時(shí)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(yù)壓結(jié)果匯總表1預(yù)壓結(jié)果匯總墩號(hào)平均彈性變形13#15mm14#13mm五、成果應(yīng)用本次觀測(cè)較真實(shí)模擬箱梁施工的加載過(guò)程,達(dá)到了預(yù)壓目的，驗(yàn)證了該掛籃結(jié)構(gòu)的設(shè)計(jì)滿足安全和質(zhì)量要求。本次預(yù)壓所得數(shù)據(jù)能夠指導(dǎo)施工，預(yù)壓結(jié)果合格，滿足規(guī)范及設(shè)計(jì)要求.可運(yùn)用該掛籃進(jìn)行13#、14#主墩連續(xù)梁現(xiàn)澆施工。根據(jù)設(shè)計(jì)圖紙，設(shè)計(jì)只提拱了成橋后預(yù)拱度，在掛籃施工過(guò)程中。還要考慮掛籃變形的因素。因此，施工預(yù)拱度為掛籃彈性變形值+設(shè)計(jì)預(yù)拱度，則：對(duì)于已預(yù)壓的掛籃，根據(jù)如下公式調(diào)整底模標(biāo)高：底模頂面標(biāo)高二梁底設(shè)計(jì)標(biāo)高+設(shè)計(jì)預(yù)拱度（1.5cm）+彈性變形即13#底膜頂面標(biāo)高=62.312+0.015+0.015=62.34214#底膜頂面標(biāo)高=62.312+0.013+0.015=62.340后附表：預(yù)壓結(jié)果表格

附件1:沉降觀測(cè)點(diǎn)橫斷面示意圖掛籃預(yù)壓測(cè)點(diǎn)布置圖I左前吊測(cè)點(diǎn)A1點(diǎn)DU豳點(diǎn)B6點(diǎn)D12附件2:底版預(yù)壓觀測(cè)點(diǎn)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(yù)壓觀測(cè)點(diǎn)平面布置圖圖214#墩底板和上橫梁預(yù)壓觀測(cè)點(diǎn)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(yù)壓沉降觀測(cè)數(shù)據(jù)記錄序號(hào)編號(hào)布點(diǎn)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(shí)12小時(shí)24小時(shí)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