Abstract:Jiangdong Bridge (Qianjiang Nine Bridge) is located in the northeast corner of Hangzhou city, west Xiasha, east Xiaoshan, is an urban express road. There is Qian River tide watching near the bridge site, which requires higher bridge landscape. The river is 2.1km wide and located in the middle of the estuary of Qiantang River with complicated dynamic conditions. The bottom of the river bed is washed and silted violently. The length of the bridge is about 2253m. The main bridge structure is two self-anchored suspension Bridges and one prestressed concrete rigid frame bridge. The non-navigable bridge in the river is a prestressed concrete continuous beam bridge. The self-anchored suspension bridge with navigable holes is unique in shape, meaning "Qian Jiang sailing shadow". Its main span is 260m, and it adopts single-column bridge tower, separated steel box stiffened beam, space cable, and side span without sling. This type of suspension bridge has no precedent in China and abroad. This paper mainly introduces the design conception and construction characteristics of Jiangdong Bridge.

Abstract:Hangzhou Bay Beihang Bridge is a diamond-shaped double-tower double-space cable-plane steel box girder cable-stayed bridge with a main span of 448m, with a navigation clearance of 47m. It is designed according to a two-way six-lane expressway with a design speed of 100km/h. In order to improve driving safety, for the first time in China, a wind barrier is set outside the railing (from 4.27m near the tower to 3.4m far). In order to ensure the meaningful landscape of the whole bridge, a cable shock absorber with steering mechanism is developed. Theoretical analysis of the whole bridge cable is carried out and a real bridge test after installing the shock absorber is carried out.

Abstract:A bridge project is a cantilever type outward arch ribbed arch bridge, the main bridge span 111m, arch rib using box section, combined with the design of the bridge, this paper analyzes the design concept, shape characteristics and mechanical characteristics, as well as the selection of construction scheme and construction method.

Abstract:Based on the practice of bridge strengthening engineering for many years, the concrete methods of external prestressed concrete Bridges and some problems in design and protection are introduced in detail. Finally, the concrete characteristics of two typical bridge reinforcement cases are analyzed, which provides some reference for using external prestressing method to strengthen the same type of Bridges.

Abstract:Due to environmental impact, overuse and material defects and other factors, the structure will appear with the passage of time such as concrete carbonization, steel rust expansion, concrete defects and other diseases. These diseases have a great negative impact on structural durability. In order to ensure that the structure can work normally, it is necessary to take some strengthening measures. Taking the strengthening project of Yongjiang Bridge in Nanning City as the research background, this paper analyzes the causes of several diseases which have great influence on the durability of the structure, and introduces the working principle and construction technology of different strengthening technologies. The comprehensive strengthening technology used in the project mainly includes: brushing permeable concrete rust inhibitor, epoxy mortar or epoxy concrete to repair defects, pasting glass fiber cloth, painting anti-corrosion coating, etc.

Abstract:The deformation behavior of prestressed CFRP reinforced concrete beams without unloading is calculated and analyzed by using ANSYS finite element analysis software. In the calculation, the method of temperature rise is used to apply the prestress, and the life and death of the unit is used to realize the reinforcement without unloading. By comparing with the experimental results, it can be seen that the numerical results agree well with the experimental analysis results. On this basis, the expanded calculation of different initial damage amounts and CFRP strengthening amounts shows that the initial damage beams have almost no effect on the bearing capacity of concrete beams, and the bearing capacity of concrete beams can be effectively improved by increasing the number of CFRP strengthening layers.

Abstract:The paper emphasizes the superiority of pressure anchor cable, and analyzes the necessity of combining soil anchor and anchor cable for soft soil deep foundation pit. After thinking about the past design, it is suggested that the safety factor of slope and foundation pit engineering should adopt three stages: k up, k middle and k down, where k down > A surname On k, the average value of the three meets the standard k value. It is also pointed out that under certain conditions, the overall stability of the anchor cable should be considered in the design. The temperature stress of bolt in rock slope in tropical area cannot be ignored.

Abstract:Taking Baoshan Bridge approach bridge of Longjiang Bridge in Yunnan Province as an example, this paper analyzes and compares the scheme using lead core isolated rubber bearing with the traditional one. Compared with the traditional rigid resistance method, it is proved that the shear force and bending moment of the pier column can be greatly reduced when the bridge is designed with lead core rubber bearing in high seismic area.

Abstract:Nanping cross-River Bridge in Fujian Province is a new type of bridge with suspension cable-cable-stayed cooperation system, which has the characteristics of high construction technology and complex construction process. In the face of the strong pressure to complete the superstructure construction in a short time, the diameter of the embedded pipe of the main cable anchor is too small, and the anchor head of the main cable can not pass through this difficult problem. In view of the existing problems, the paper introduces several solutions, such as grinding the inner diameter of the embedded pipe, developing a special reaming equipment, drawing and stretching the special specimen and replacing the anchor head of the main cable. By comparing with each other, an economical and convenient quick effect method is obtained, which can provide reference for dealing with similar situations in the future.