本文讨论了目前已建道路桥梁运营、养护和管理中所面临的问题、现状，对未来的桥梁运营、养护和管理的发展及研究提出了新思路，并就有关的关键技术进行了研究和阐述。

Based on one typical cable-stayed bridge with mono-tower and mono-cable plane, the shear lag effect in the kind of bridge with multi-cell box girder is analysed by spatial finite element method. The influence of some factors such as the type and transverse acting location of external load on the shear lag effect is explored. Some useful conclusions are drawn through this study.

A comprehensive investigation of the stochastic response of the approach bridge of Sutong Yangtze River Bridge-PC continuous rigid frame box girder bridges subjected to spatially varying ground motions is completed. A frame member system model considering the geometrical non-linearity caused by the dead load state and the soil-foundation-structure interaction effect is presented. The wave passage, incoherence and site-response effects are separately discussed in detail. It is pointed out that each component of the spatially varying ground motion model has important effects on the dynamic behavior of the bridge. Therefore, the variability of the ground motions should be considered in the design of this kind of bridges.

笔者有幸参加了中意国际合作研究“舟山连岛工程金塘海峡悬浮隧道（或称阿基米德桥）技术可行性研究”项目，并进行了有关的研究，这里简要概述悬浮隧道的概念和在国内外的研究进展。

The prestressing load is one of the key loads in P.C.bridge under normal service stage. In modern P.C.bridges, besides the longitudinal prestressing forces, the transversal and vertical prestressing forces are often used. The spatial stresses effect caused by prestressing force is very evident and the behaviour of structure is complicated in the P.C.bridges. The traditional elementary beam theory can not analyze the spatial stresses effect. Based on the conventional 3D isoparametric finite element method, one new, more convenient and effective element—degenerated solid element for analyzing all kinds of complicated structures is presented. It assemble the advantages of the shell element and 3D isoparametric element. In the end, a typical three-span P.C. continuous rigid-frame box girder bridge is analyzed by the method. Influence of prestressing force on spatial effect is explored. The analysis results indicate that the degenerate solid element is a effective and practical method.