In this paper, the impacts of environmental vibration on precision instruments as well as the vibration allowances of precision instruments are introduced firstly. Then the integrated model of a high-rise building is established, and the vibration responses of the floor where a precise instrument is fixed are calculated by inputting micro-vibration loads. The passive control method is used by putting several lead rubber bearings at the bottom of instrument and at the bottom of building separately, and the isolated vibration responses are calculated and analyzed. Some valuable conclusions are obtained by comparing the vibration responses of isolation system and non-isolation system with acceptable values according to the environmental vibration codes for precise instruments.

A new type of flexible suspension tension structure (FSTS) is presented in this paper, which has the advantages of high-efficiency, convenient construction and wide application sphere, and it is also a kind of green and low carbon structure. In order to investigate the mechanical behavior of FSTS under the vertical load, series of structures under 10 groups of upward loads and 8 groups of downward loads are calculated with the matrix analysis method. The results show that the passive tensions of cables and displacement in the middle of span present approximate linear features under the downward loads. However, there are double broken linear features in FSTS under the upward loads. So this regularity can be utilized for the simple analysis and two-stage design calculation. Finally, the reliability of FSTS with the initial tension is investigated with the interval method. 81 kinds of structures with different initial tension are calculated, and the influence regularity of the initial tension in the back cable and the bottom cable are given. It is found that the deformation of FSTS is more sensitive to the initial tension of cables. Consequently, the initial tensions of cables are dominated by deformation of structures under design and construction.

Reactive powder concrete (RPC) is one of new composite material, which is applied in the pilot project of the railways construction. According to the literature survey and test data report, the major factors which influence the reliability of 32m prestressed RPC girder in railway bridges are given in this paper. Furthermore, combining numerical simulation with finite-element method, the reliability of the prestressed RPC girder is calculated. The results show that the failure probability and reliability parameter can be obtained through direct sampling method and the latin hypercubic sampling method. The reliability parameter of fracture is 3.9 with two methods, while the reliability parameter of deflection control is 4.1 and 4.2 respectively with the two methods, and the reliability parameters meet the demands of norm of railway bridges. Consequently, the RPC is safety to be used in the railway bridges.