Research And Analysis Of Widening Alteration Of Dalian Northeast Road Cloverleaf Junction

Traffic increasing of our country is accelerated By the rapid development of our national economy, many bridges in most city have been turned into bottleneck from expedite works, enhancing the traffic ability of current bridge by widening alteration is passed for the new problem. In virtue of many engineering practice, plentiful theory and experience are summarized by national scholars, however, according to the special status and complicated character of cloverleaf junction in the municipal traffic, there is no research about widening alteration of cloverleaf junction. By research to the widening alteration of Dalian northeast road cloverleaf junction and a mass of FEA (finite element analysis) calculations, a widening alteration method that not impacts the current traffic under the bridge is been seeking, main jobs of this paper are as follows:(1) According to many already finished widening alteration of bridge, the in common use widening alteration methods and strengthening techniques are summed up, by the contrast between all the methods and techniques and after the widening alteration area is confirmed, northeast road cloverleaf junction is decided to be widen with bilateral symmetrical mode, cantilever is protruded from initial main beam, superstructure and bridge pier is to be strengthened by external tendons and concrete enclosures.(2) Based on FEM (finite element method), by dimensional calculation toward widening structure, the widening alteration plan is improved and the improved structure is calculated again, the ultimate bearing capacity and normal serviceability requirements about the superstructure after widening alteration are confirmed.(3) According to calculating method of strengthening architectural concrete pile, the calculating formula of strengthening bridge pier is deduced, by calculation toward ultimate bearing capacity and crack width of bridge with two methods and the strengthened pier cap is analyzed with FEA software, the ultimate bearing capacity and normal serviceability requirements of the strengthened bridge pier are confirmed.(4) According to the request that traffic of northeast road cloverleaf junction should be improved and resumed in best times and the strengthening and widening characters of the whole structure, the order of "first bridge pier, then superstructure, first strengthening, then widening " is decided, the constructing of widening alteration is deepened by detailed construction management.