支撑法在墩柱式盖梁施工中的应用.rar

支撑法在墩柱式盖梁施工中的应用

作者指出，在钢筋混凝土结构桥梁建设的盖梁施工中，采用的传统工艺是搭设满堂架支撑体系，此种施工方法不仅浪费材料，而且耗工费时，如采用悬空支撑法进行施工，就大大节省了周转材料，加快施工进度。悬空支撑法通常分为钢棒支撑法和柱箍支撑法两种施工工艺。作者认为，钢棒支撑法施工较烦琐，且影响混凝土外观质量。作者在实践中用钢制柱箍作为盖梁支撑点和贝雷片组装主龙骨的施工方法就避免了以上缺点，取得了良好的效果。

作者的实践是在国道206线山东烟台黄新段第六合同段的田庄大桥。大桥全长231.06m,桥宽28m，分左右两幅，9孔25m，上部构造采用后张发预应力混凝土T梁，共有T梁108片，下部采用柱式墩，柱径1.5m，桥墩盖梁截面尺寸170×160cm，每个盖梁自重82T，共有盖梁16个，墩柱高度平均15米，混凝土强度等级C30。

在施工中，柱箍采用6mm厚钢板制作，高700mm，背面采用槽钢作为竖楞，竖愣间距≤400mm7，柱箍内径大于柱径15mm，每个柱箍由两个半圆形钢箍组成，两个半圆形钢箍在柱上安装后相接面有50mm，空隙，以保证钢箍之间用高强螺栓连接好后能与墩柱挤压紧密，柱箍内壁用万能胶粘贴8mm厚橡胶垫，用以增加柱箍与墩柱的摩擦力。

由于盖梁的全部施工荷载均由柱箍承受，所以柱箍与混凝土柱摩擦力是否能承受以上荷载，是确定柱箍是否能够安全使用的关键，必须经试验确定后方可使用。试验方法是先将柱箍安放在距地面约80cm处，每个柱箍的2个半圆钢箍之间用10个φ16高强螺栓连接牢固，柠螺栓时两边对称拧紧。在柱箍下部两侧放置150t液压千斤顶各一台，千斤顶与油泵连接好后，同时打开两台油泵进油阀，使千斤顶向柱箍作用力，通过油表的读数计算出作用力的大小，当柱箍开始滑移时，记下油表读数，算出作用力大小，即可得知柱箍所能承受的极限荷载。在莱州田庄大桥的柱箍承载力试验中，柱箍极限承载力可达90t，实际所承受荷载为50t，施工安全系数达到1.8,完全满足施工要求。选用4台螺旋千斤顶，方在柱箍上，用于承受上部荷载和调整高程和盖梁坡度，千斤顶吨位必须大于上部结构所传递的荷载。采用3×1.5m工程用标准贝雷片，每个承压梁由几个贝雷片组成，贝雷片与贝雷
Support in pier cap beam type of construction

The authors note that in the construction of reinforced concrete bridge girder constructing, using the traditional process is the erection full house frame support system, such a construction method not only wastes material, but takes too much time, such as the use of floating support construction method, the significant savings the turnover material, speed up the construction progress. Hanging bar support method is usually divided into two columns supporting laws and support law hoop Two construction technology. The author believes that a more cumbersome construction steel bar support method, and the appearance of affecting the quality of concrete. On the steel columns used in practice as a cap beam hoop support points and Bailey to the construction method of assembly of the main keel to avoid the above shortcomings and achieved good results.

The practice of national highway 206 in Yantai, Shandong Province Huang sixth paragraph to paragraph Grange contract bridge. Bridge length 231.06m, bridge width 28m, about 2 hours, 9 holes 25m, post-tensioned superstructure with prestressed concrete T beams issued, a total of T beam 108, the lower use of pier column, column diameter 1.5m, Pier Cap beam section size 170 × 160cm, each capping beam weight 82T, a total of capping beam 16, the average pier height of 15 meters, concrete strength grade C30.

In construction, the column coupling with 6mm thick steel plate production, high 700mm, use the back channel as a vertical flute, vertical blank interval ≤ 400mm7, column hoop diameter greater than the column diameter 15mm, each column consists of two semi-circular steel hoop hoop component The two semi-circular steel hoop in the column after the installation phase surface with 50mm, gap, to ensure high-strength steel bolts used to connect between the hoop after a good tight squeeze with the pier, column inner wall hoop 8mm thick rubber with adhesive paste pad to increase the hoop and the pier column friction.

As the capping beam by the full working load bearing pillar hoop, hoop with concrete columns so it can withstand more load friction, is to determine whether the safe use of column hoops key test must be determined before using. Test method is to first column hoops placed in the ground about 80cm from the Department, each column of the two half-round steel hoop hoop 10 between the use of high-strength bolts connecting φ16 firm, symmetrical on both sides of lemon bolts tightened. Placed in the column on both sides of the lower hoop each one 150t hydraulic jack, jack connected with the pump, the same two pump inlet valve open, so jack hoop force to the column, through the oil meter readings to calculate the size of force, When the column began to slip when the hoop, down the oil meter readings, calculate the force size, you can hoop that column can bear the ultimate load. Grange Bridge column in the Laizhou hoop bearing capacity test, the column collar bearing capacity up to 90t, the actual bearing load is 50t, construction safety factor of 1.8, fully meet the construction requirements. 4 sets of screw jack used, hoop on the side column for the upper load bearing and cap and adjust the elevation gradient, jack must be greater than the upper structure of the tonnage of the load transfer. With 3 × 1.5m engineering standards Bailey, each bearing beam composed of several Bailey, Bailey and Bailey