疏港公路在海底抛石施工中,由于海面风力强、潮汐的影响大,施工和测控难度相对较高.为了适应海上疏港公路抛石施工的需要,基于DTM建模技术自主研发了海底抛石施工计算机辅助系统,用Visual Studio 2005编程实现了海底地形云图显示、抛石工程量计算和动态水深预警等相关关键技术.在此基础上,系统研究了疏港公路海底抛石施工的工艺原理、流程和具体操作要点.研究结果表明:海底地形云图和动态水深预警可以直观反映海底地形情况,为施工组织和进度安排提供指导;根据潮水特点和不同船只安全航行水深,利用开体驳、平板驳等多种船只协同施工配合抛石,可以有效避免船只搁浅;采用陆抛进占法和大侧小中抛石法进行抛石施工,可确保抛石的准确性和密实性.
Currently, for the analysis of complex bridge based on beam element, the calculation of cross-section torsional inertia moment is still an unresolved technical problem. Most current calculation of section torsional inertia moment is an approximate analytic method for two-dimensional cross-section, which is not fully consistent with the actual situation, and do not consider the effects of diaphragm in bridge. In order to analyze accurately cable-stayed bridge, suspension bridge and other complex bridge structures based on beam element, the calculation method of section torsional inertia moment based on finite element method (FEM) is invented in this paper. Firstly, setting up local cantilever fine model with solid element or shell element and applying torsion on the end of cantilever. Secondly, calculating the torsion angle of cantilever by FEM method and then the torsional moment through equivalent beam method. Finally, the examples of the section torsional moment calculation of concrete model with solid element with diaphragm and steel girder box model with shell element with diaphragm are used to verify the calculation method, which is applied to the suspension bridge design and construction control special software SBNA developed by Research Institute of Highway Ministry of Transport. Taizhou Bridge under construction is one of the examples.
