菊花石桥初步设计.pdf

摘 要 本次毕业设计为菊花石桥初步设计，根据设计任务书要求，依据现行公路桥梁设计 规范,综合考虑桥位的地质、地形条件，提出了混凝土简支T梁桥﹑预应力混凝土连续梁 桥以及中双塔预应力混凝土斜拉桥三种方案比选，依据“适用、经济、安全、美观和环 保”的原则确定4×30m预应力混凝土连续箱梁桥作为设计方案，采用顶推法施工。 对桥梁的纵断面﹑横断面进行设计，拟定主梁构造细部尺寸，采用等截面梁，截面 形式为单箱双室 ，梁高2m 。应用Midas Civil 有限元分析软件对结构进行分析，根据拟 定的桥梁尺寸建立顶推法施工桥梁模型，并进行施工模拟得到主梁各截面恒载内力，计 算车辆荷载和人群荷载活载内力，计算温度梯度内力和支座不均匀沉降内力。计算基本 组合，频遇组合，准永久组合后得到相应内力包络图。 根据内力包络图，估算预应力钢筋的数量，其中5号截面底板钢束最多为21束，9号 截面顶板钢束最多为12束。按照预应力筋布置构造要求和布置原则进行预应力筋的布置， 进行预应力损失和有效预应力的计算。对主梁正截面抗弯承载力，正﹑斜截面抗裂承载 力，混凝土法向压应力及挠度验算。 关键词：方案比选，连续梁桥，顶推法，结构设计，结构验算 I ABSTRACT The graduation design is the preliminary design of the chrysanthemum stone bridge. According to the requirements of the design task book, according to the current highway bridge design specificationn. considering the geological and topographic conditions of the bridge, the concrete simply supported T-beam bridge and the prestressed concrete continuous beam bridge are proposed. According to the principle of “applicable, economical, safe, beautiful and environmentally friendly”, the 4×30m prestressed concrete continuous box girder bridge is selected as the design scheme and the top push method is adopted. The longitudinal section and cross section of the bridge are designed. The dimensions of the main beam structure are drawn up. The structure is analyzed by Midas Civil finite element analysis software. The bridge model is built according to the proposed bridge size, and the construction simulation is carried out to obtain the dead load of the main beam. Internal force, calculate the internal load of the vehicle load and the crowd load, calculate the internal force of the temperature gradient internal force and the uneven settlem