（Continuous Bridge）
【Abstract of the Project】Continuous bridges belong to a continuous system statically indeterminate structure, because of its structural rigidity, structural deformation, less continuous bridge structure across the joints, etc., to obtain a continuous bridge in today's rapid development, become a common form of medium-span bridge structure. The prestressed concrete continuous beam bridge is the main form of structure, widely used in today's small and medium-span bridges.
Continuous weight is closely related to its internal forces beam bridge construction methods, to promote and constantly improve its method of construction, until now, continuous beam bridge construction method has matured. Commonly used methods of construction: construction with scaffold law, hole-by-construction method, the cantilever construction method, pushing construction method. The method of the above construction, in addition to support construction and a continuous drop in the bridge of the construction process, there is no system conversion, the internal force analysis for analysis according to the bridge structure, the other construction methods in structural analysis have to be considered when the structure during construction internal forces or stress generated by the conversion system stack. When continuous beam internal force calculation to pay attention to this feature.
Prestressed concrete continuous bridge common form section beam are hollow, T beams, box beams and the like. The selection and bridge sections span, architecture, meet the requirements, construction methods, construction conditions are closely related. For continuous beams, plate and single-beam T-section is only suitable for less than 40m city highway. Sectional form also has a great relationship with the deck width. Since the increase in the width of the bridge cross-section unit member deformed. For wide bridge, usually used separate single-chamber box beam. Separate settings box beam longitudinal seams in the middle, single bridge span up to 25m. Its load distribution coefficient is small, economical and practical, if the cantilever construction method, the construction can be pided into boxes, effectively shorten the construction period, the construction is 
also more convenient.
Prestressed concrete continuous box beam is the most common form section beam bridge, is widely used in modern bridge. Box beam its torsional rigidity, construction and post-use structure has good stability. Adapted to the bridge with positive and negative moments, because there is a large box beam concrete roof and floor area, can effectively resist the conquest moment, but also improve the position of arrangement of steel beams sufficient to meet the requirements of reinforcement. Diverse construction methods can better adapt to different geographical environment, with a broader scope. Load-bearing and power transmission structure by combining the various components together by force, which greatly improves the efficiency of cross-section, with better economic benefits. Beam is a space architecture, structural torsional stiffness, especially for wide bridge, Curved bridge and other bridges.
The design of the main content is designed  Dongcang bridge in Suzhou City, there are three designs: a program of prestressed concrete continuous box beam bridge; Option two, prestressed concrete simple T beam bridge; Option Three, Span Prestressed concrete Composite Arch. Recommended solutions for a program is the first one prestressed concrete continuous box beam bridges.
The three-span bridge of variable cross-section design, the main span  is 80m. For box-section, side span and main span ratio of 0.5 to 0.7, combining with the construction method of the bridge,the side span takes 50m. Superstructure’s selection is box section, which is pided into two separate bridge construction. Single-section bridge chooses single box double room beam. Box sectional deformation at the support beam span calculation usually take the middle span of 1/18 to 1/16; cross-sectional height is usually taken in high bearing section beam of 1 / 2.5 to 1 / 1.5. Beam bottom curve using quadratic parabola. The bridge supports of bridge height H = 4.5m, span at high beam H = 2.1m. For the aesthetic requirements, beam bottom curve selection parabola, so the end of the beam changes more smoothly concise. Deck Pavement: 8cm + 10cm concrete waterproof layer of asphalt concrete wearing course, a total of 18cm. Main Bridge Pier Foundation 1200 using 12 bored piles, pile cap thickness take 2m. In order to reduce the flow of the Bridge Foundation of impact, the two Caps transverse to the outer edges of the shape of an arc-shaped design, the main bridge piers of Double Shaft Piers. 预应力混凝土连续梁桥设计+图纸(2):http://www.751com.cn/gongcheng/lunwen_41390.html