The Research Of Horizontal Force Distributions On Flexible Pier Girder Bridge Of Pile Foundation

Using flexible piers can reduce the temperature influence and the secondary internal force which caused by shrinkage and creep in concrete, reduce the amount of masonry, cut down the cost of the bridge. At the same time, it can also reduce the waterproof area of the pier and the scouring to piers, improve the capacity navigation and drainage of the bridge, make the bridge type more beautiful, and so on. As a result, flexible piers have been widely used in the municipal road and highway bridges. But the calculation of horizontal force distribution on flexible piers is very complex. Especially, when the numbers of linked bridges are large, it is very difficult to calculate the horizontal force of the flexible pier by hand. Until now, under the pier base, the interaction between pile and soil haven’t been solved, which lead to the distribution of horizontal force on flexible piers is not accurate and the force calculation and structure design of flexible piers is inaccuracy.In this paper, on the basis of the integrated stiffness method, which is the traditional method of the distribution of the level force on flexible piers, the interaction between the flexible piers under piles and soil is analyzed and the integrated stiffness model of base pile and soil is established. And on this basis, the software have been develop, which can calculate the level force of flexible piers. The main researches are as follows:First, it has been found that the calculation process of the horizontal force distribution on flexible piers is complex and the calculation results are conservative through the literatures. So, in this paper, the new research methods and technical routes are proposed.Second, by using the principle of the integrated stiffness method, the relationship between the base pile and the soil is brought forward to suppose and analyze pile and its surrounding soil which bear horizontal thrust together constitute a organic whole. With their nature, there are some assumptions following:pile and pile surrounding soil have been considered as elastomer, they simulated to springs, the mathematical model of the relationship between the base pile and soil is obtained through spring simulation, on the basis of the model, the mathematical relation the base pile and soil is established.Third, on the basis of the mathematical model of the base pile and the soil, combined with the programming functionof Visual Basie, we develop the new software, which is used to calculate the horizontal force on flexible piers. This software is available for simply supported girder bridge, continuous beam bridge. It is also suitable for flexible pier in the form of thin-walled type, column type, hollow type, entity type and so on. In this software, some probable things have been simplified. Connected pier is simplified and only the horizontal force calculation of flexible pier in a joint is considered. It is supposed that the stiffness of the fixed support is infinity. Due to the change of the annual temperature, concrete shrinkage, and the slow continuous process of creep, the anti-push rigidityfind of pile is reduced. The variable section column or the hollow column pier is regard as the rectangular section pile. Finally, by means of an engineering example, compared the hand-count calculated results with the results gained by the software, we find that the horizontal force distributions gained by the software are more ideal. So the software is valuable for engineering.