Rugao Evergreen Sand Bridge Construction Project Bridge Site And Bridge Type Study

The big bridge of Changqingsha is going to be set up in Yangtze River naturally harbor waterway top an upper stream for new the hole of yuehan 1.7 km, which is a central part of Yangtze River and a segment of Rugao sand , its upper stream is fujiang, the downstream is a tongzhou waterway.The left bank is city of Jingjiang, Rugao, and Tognzhou, the right bank is city of zhangjiagang.The bridge site research basic principle mainly has:The river course, the waterfront are suitable straight, the river bed, the deep deep line are stable, the river potential is stableEngineering geology and hydrogeological conditions relative good, the regional geology quite is stableSurface of the river relative narrow, the bridge length is as far as possible short, reduces the project scale, reduces the project construction costThe route condition is as far as possible good, affects slightly to the shippingBoth banks wiring is smooth, with road network and both banks urban development plan development, waterfront development use coordination.After studying the Changqingsha's characteristics of weather, hydrology( the hydrology sediment characteristic, path flows, current, tide etc.), river, engineering geology, shipping etc. proceeds the detailed investigating, main conclusion in research in term in a developments in bridge:1,Water current speed not very fast, the water is not deep, the river bed turns into the complicacy, but is already stability.2,Geology circumstance is still good, the part exsits bad geology, but do not affect the stability and safety of the bridge.3,The width of the river is narrow, can shorten the bridge length, economize the engineering price.4,Satisfy the V class channel request. 5,Links up with the Shugang highway route smoothly.Based on the analyze of the argument, argument intend to set up the bridge is viable and reasonable.The bridge draws up the principle which should follow1,The bridge is wide, set up the bridge water inside foundation is unavoidable.Because the foundation construction inside water is very difficult, the work period is long, and the ships that resist the request bump the shot, building the price expensive, is a key to control the work period, investment factor.Therefore, proper basal quantity in reasonable, to the best reduce water.2,At consider to satisfy a car the safety, comfortable demand of at the same time, value well the landscape design, as far as to shape beautiful, the bridge acrosses to arrange the coordination, and match with with surroundings environment well.3,Research that value the construction project, join together the construction term of this bridge engineering, choose the reasonable project, to reduce the construction difficulty, lower the construction risk, start construction quickly degree of progress, guarantee the engineering quantity, economize the investment. 4,According to the condition of the bridge bed cross section, in consideration of the channel water requests, and start construction the period is at the request of having the enough channel water to insure normal shipping, combining the consideration reduce to the best the ships bumps the shot buttresses all rate.5,Bring in, digest, absorb the domestic, outside advanced technique and the successful experience, to make to design the project technique sensible and ecnomic.The bridge analysisAs well as is open to navigation the request according to the river bed cross section shape and the flood discharge demand and so on, the 60～80m span may supply the choice the bridge to have Liang, the continuous frame, V pillar rigid frame, the slanting leg rigid frame, the tie bar arches continuously, receives the arch, the handbasket type tie bar arch, the diagonal cable bridge, the partial diagonal cable bridges, the truss bridge and so on.The truss bridge must slightly arch the economy compared to the tie bar, but its amount of space occupied oversized, the line too is mixed, the construction is trivial, from has constructed this kind of bridge the contour to look, is not very artistic, therefore does not include it this plan;The slanting leg rigid frame and has thrust force to receive the arch, is the thrust structure, the general construction is economical in the geological good bridge site, this design geological condition is ordinary, therefore does not include this design proposal;The continual rigid-frame bridge stress characteristic and Liang is continuously similar, it constructs the bridge condition is Shan Dunhuo the double thin wall bridge pier, must have the big flexibility to adapt the temperature change, this requests the bridge pier to have certain altitude, but this scope bridge pillar Gao Zheyi 5 meters, therefore takes this bridge not suitably the design proposal;V pillar bridge construction cost and Liang is continuously equally matched, but the relative this project design and the span say, the bridge pier too is low, makes V pillar not to be uncoordinated, therefore does not include this bridge plan;Pure diagonal cable bridge, in this span scope not too economical, therefore does not include this bridge plan;In the span big arched bridge plan, arches besides the general tie bar, also had considered in the bird type flexible tie bar receives the arch, although its maintenance and trades the rope the request to be stricter than regularly the general tie bar arch (a suspension bar to fall off then partial bridge floor will break down collapses), but because it has saved a tie bar compared to the tie bar arch, lightened the arch rib burden, thus reduced the arch rib cross section, will have certain efficiency.Draft according to the actual circumstance intend to arrange three bridges type and the construction project proceeds to synthesize the comparison, making sure the project with the main bridge adopt the pole arch,the leading bridge adopt prepared concrete wihe change base continues beam is reasonable.