Research On Rational Completion State And Construction Control Of Long Span Bridges Based On Influence Matrix

During constructing bridges, it is very important to control the construction process. It is a key to realize the ideal design point after bridges constructed. It is very important to determine the rational completion status. It not only provides optimum object for process control and facilities for structure construction, reduces erection time for a project, but also can take full advantages of architectural characteristic and save material, reduce construction cost.This dissertation proceeds the study on determining the rational completion status and controlling construction process for bridges. With the help of a large FEM calculation and analysis program, making cable-stayed bridges, tied arch bridges, self-anchored suspension bridges as study objects, this dissertation takes full advantages of many components' adjustable characteristic of bridges to change the distribution of internal force, optimizes structural design. Analyzing the influence matrix formation theory on the basis of geometric linear and non-linear, this dissertation studies the structural adjustable computation theories and their application on bridge design and construction on the basis of influence matrix. Totally, there are several conclusions:1,The dissertation summarizes the geometric non-linear influence factors of bridges structure and measures to deal with each geometric non-linear influence factor. Then, the dissertation derives the influence matrix method for bridge structure computation and discusses the structural adjustable computation theories on the basis of geometric linear and non-linear. Several universal forming influence matrix methods are compared, those are, modifying total rigidity matrix method, compelling distortion method, structure alteration method. Forming influence matrix method on the basis of temperature change and normalization principle are proposed.2,The dissertation summarizes several methods to determine the rational cable forces of cable-stayed bridges and compares advantages and disadvantages of each method and proposes a synthesis method on the basis of influence matrix to determine the rational cable forces of cable-stayed bridges. That is, using rigid support continuous beam method, makes the main beam of cable-stayed bridge as the rigid support continuous beam and its moment of flexion as control object. The influence matrix of cable forces to the moment of flexion of main beam is introduced. Inner force balance equation of main beam is created on the basis of inner force balance of main beam and the rational cable forces of completion status is obtained. By discussing many construction control methods of cable-stayed bridges, the influence matrix method to determine the cable forces of construction status are studyed. The dissertation proposes an iteration method to solve the rational cable forces of construction status while considers geometric non-linear influences. By discussing multiple objective optimizational method, a method on the basis of influence matrix to make error adjustment of cable-stayed bridges are proposed.3,The dissertation proposes a method synthesizing rigid hanger method and automatic adjustment cable force method on the basis of influence matrix method to determine the rational completion hanger force of tied arch bridges. Firstly, rigid hanger method is adopted to make rigidity of hanger a super number, obtaining vertical displacement of hangers and collar beams crossing and influence matrix of hangers inner force to vertical displacement of collar beam nodal points. Then, hangers inner force is modified by using automatic adjustment cable force method and hangers inner force of rational completion status are obtained. By researching the influence of hangers inner force one each other during construction, a reverse demolishment construction measure is obtained on the basis of influence matrix. This method can make tied arch bridges obtain ideal design status by stretching only one time. At last, the dissertation obtains error adjustment method of hangers inner force on the basis of influence matrix.4,Mechanical characteristic of construction control of self-anchored suspension bridges is tested. By analyzing the stress characteristic of structure of self-anchored suspension bridges, the dissertation obtains a synthesis method to determine hangers inner force on the basis of least-energy principle and compatibility of deformation. By studying the model of completion status of self-anchored suspension bridges, minimum bending energy method is proposed on the basis of influence matrix. This method can consider live load and dead load. The linear and non-linear construction control principle is obtained on the basis of influence matrix. The method can reduce tension times and construction cost. The error control theory of self-anchored suspension bridges is proposed on the basis of linear and non-linear influence matrix methods.