Research On Dynamic Responses Of Long-span Bridge-building Station Structures Induced By Vehicle

With the arrival of new century, the structures of large-scaled railway stations nowadays has been developing towards the directions of huge size, multifunction and spatialization. More and more large-span spatial steel structures with unique shapes and novel forms appear. The bridge-building stations are since mutually independent and then close related in a station structure form which is syncretism of bridge and building. However, the structure form of bridge-building is complicated. The base of the upper building structure is the bridge structure, so the vibrations caused by high-speed trains have an influence on upper large span structure and environment around.Currently domestic and international literature about the large span steel structures which is bridge-building is infrequent, vehicle induced vibration response is based on condition that trains'uniform motion through the station, and lack the calculation analysis based on measured data. For the large station structures of bridge-building, trains pass in and out station is actual familiar work condition. Brake force and startup force also cause the vibration of bridge structure besides vertical load when trains pass in and out station. So, it is necessary to research vehicle induced vibration response against characteristic of the large station structures which is bridge-building, and ulteriorly evaluate the upper structure floor vibration comfort in the most disadvantageous work condition, presenting reasonable and feasible vibration controlling suggestions if necessary.The paper aims at large station structure with background of the Wuhan Railway Station on the Special Passenger Railway from Wuhan to Guangzhou, the structure of bridge-building is divided into two substructures, which are train-bridge substructure and upper large-span steel substructure. Vehicle-induced dynamic responses of the large station structures which is syncretism of bridge and building is researched systematically. The following research works are carried out:(1) As to the train-bridge substructures, moving load-bridge calculation model is established, and according to the model, vibration response of Wuhan station rail girder subjected to coupling effects of train vertical force and train lengthways force is researched. Modality tests based on environment motivation and rail girder vibration response tests based on train loads are made, and correctness of the rail girder model and effectivity vehicle-induced method are checked.(2) Calculation model of the upper steel structures of Wuhan railway station is built. Obtaining support reaction of bridge from calculation results of Wuhan railway station box girder'vibratory response, and use the support reaction as input load of upper large span structures, dynamic response of upper large span structures is calculated.(3) Wuhan railway station's waiting floors are divided into several little areas, select equably some points from every area and pick up the peak value of vibration acceleration of the points. Then according to United States Steel Association AISC-11 evaluation criterion, evaluating comfort degree of every points. Modality tests based on environment motivation and vibration comfort degree tests based on train loads of Wuhan railway station's waiting floors are made. Also correctness of the floor model and feasibility of calculation method are checked respectively.(4) According to above-mentioned analysis method, vibration effect of Wuhan railway station's waiting floors in the most disadvantageous work condition are calculated, and floor vibration comfort is evaluated.