中文摘要：

针对桥梁无应力构形求解及顶推梁体拼装施工控制传统方法等的不足，结合背景工程，研究并解决了拼装顶推施工钢主梁理论无应力构形的简便确定和高精度控制问题。用简便的一次落架法确定了顶推梁体无应力线形，将梁体无应力构形区分为立面、平面和横断面无应力构形，并明确可忽略扭转变形影响的钢箱梁或钢槽梁无应力构形控制应重点关注立面构形，在此基础上给出了各梁段预制构形确定的方法，根据顶推梁体无应力构形实现过程中梁体纵向位置频繁变化的突出特点，用提出的相位变换法确定了各工况待拼梁段就位标高和已拼梁体实际无应力构形，对背景工程进行自适应无应力构形控制。结果表明：顸推到位的实测线形（及应力）与理论线形（及应力）吻合较好，所提出的方法正确、有效、精度高。

英文摘要：

For the deficiency in traditional solving methods for unstressed girder configuration and the assembly cor~trol for incrementally launched girder, convenient method to determine the theoretical unstressed configuration and high accuracy control method was studied. The unstressed shape of the incrementally launched girder was determined with simple installed-once- method. The unstressed configurations were divided into elevation, plane and cross section configuration. With the influence of torsional deformation neglected more attention should be paid on elevation configuration for steel box girder or trough girder. The methods for precast configuration were proposed. Through mastering the distinctive characteristics for frequent change of girder longitudinal location during constructing process of unstressed configuration for incrementally launched girder, the positioning elevation of under cast segment and unstressed configuration of already assembled segments were determined with phase transformation, the self-adaptive unstressed configuration control over the background project was conducted. Theresults show that measured configuration and stress are consistent with the theoretical ones, which proves the correctness, validity and high precision of the proposed method.