冶河大桥大直径灌注桩施工技术.rar

摘要：采用上部无水地带人工挖孔，下部富水地带机械成孔相结合的施工方案，既避免了全部用人工挖孔无法全部挖到位、进度慢、危险性大的缺点，又避免了全部用机械成孔速度慢、成本高的缺点，明显提高了工程进度，并大幅降低了工程成本。经综合测算，有效缩短工期1个月以上，节约投资12万元。
关键词：大桥 大直径桩 施工技术
1 工程概况
冶河大桥位于河北省井陉县境内，是连接井陉县东西两大动脉307国道和石太高速公路的连接线完善工程。全长550米，宽18米，双向四车道。线路起点位于县城微矿路上，与307国道形成菱形立交，然后跨越307国道、冶河、石铁分局井陉铁路货场及石太铁路正线，终点与石太高速公路连接。全桥设计为直线，15墩2台，基础为Φ1.8m和Φ1.5m桩基础，上部采用装配式预应力砼简支梁，桥跨布置为1*30m＋1*40m＋9*30m＋3*40m+1×50m＋1×40m，共计16孔128片梁。1#~15#墩采用Φ1.8m端承桩35根计604延米，0#、16#桥台采用Φ1.5m端承桩16根计320延米。桩端支承于破碎的弱风化白云质灰岩层上，桩底嵌入岩层深度大于1.7m以上，桩身为C25普通硅酸岩混凝土。
桥址处地层主要为填土、卵石及奥陶系中统白云质灰岩。自上而下分为3层，分别如下：
a 素填土：褐黄色，稍湿~湿，稍密~密实。土质不均，成分以粉土为主，夹粉质粘土薄层。该层在河槽地段缺失，在307国道附近厚2~3m，在5#、6#孔地带厚7m左右，层底标高209.91~213.18m。
b 卵石：杂色，中密~密实。卵石成分以灰岩、砂岩为主，一般粒径5~15cm，局部含大量漂石，充填物为砾石、砂粒及粘粒土，层厚11.60~16.20m，层底标高195.45~199.70m，容许承载力[σ]=400~600kPa。
Abstract: The upper water zone manual digging, lower water-rich zone hole combined mechanical construction program, both to avoid all artificial excavation dug in place not all, progress slow, dangerous big disadvantage, but also avoids all hole with a slow machine, the shortcomings of high cost, significantly increase the progress of the project, and significantly reduces the cost of the project. The comprehensive measure, effectively reduce the duration of one month or more, save investment and 120,000 yuan.
Keywords: Bridge construction technology of large diameter piles
1 Project Overview
Ye River Bridge is located in the territory of Hebei Province Jingxing, the two major artery connecting the Jingxing State Road 307 East and stone too perfect highway connector project. Length 550 meters, 18 meters wide, two-way four lanes. Start micro-mining in the county line road, and the formation of Diamond Interchange State Highway 307, then across the 307 national highway, the rule of river, stone railway goods yard and railway stations Jingjing Shi Tai Railway Main Line, the end connected with the Shi-Tai Expressway. Full Bridge designed for linear, 2 sets of 15 piers, foundation for the Φ1.8m and Φ1.5m foundation, the assembled upper prestressed concrete beams, bridge span arrangement for the 1 * 30m +1 * 40m +9 * 30m +3 * 40m +1 × 50m +1 × 40m, 16-hole total of 128 beams. 1 # ~ 15 # pier piles using Φ1.8m 35 Total 604 linear meters, 0 #, 16 # bridge abutment piles using Φ1.5m 16 Total 320 linear meters. Pile bearing on the broken weak weathered dolomitic limestone layer, pile embedded in rock more than 1.7m depth of more than ordinary silicate rock pile for the C25 concrete.
Bridge site office strata mainly fill, gravel and Ordovician dolomitic limestone in the system. Divided into three layers from top to bottom, are as follows:
a plain fill: brown yellow, slightly wet ~ wet, a little secret ~ dense. Uneven soil, silty soil composition to the main folder silty clay layer. The layer of missing sections in the river channel, thick in the vicinity of State Road 307, 2 ~ 3m, 5 #, 6 # hole zone is about 7m thick, bottom elevation of 209.91 ~ 213.18m.
b pebbles: Dark, medium density ~ dense. Pebble composition to limestone, sandstone, general size of 5 ~ 15cm, with a large number of local boulders, filling the gravel, sand and clay soil, thickness of 11.60 ~ 16.20m, layer bottom elevation 195.45 ~ 199.70m, allow Capacity [σ] = 400 ~ 600kPa.