Analysis And Processing Of Differential Settlement Of Difference Framed Structure

Differential settlement of the foundation because of the different of the structure style, the load, the form of foundation, the bearing capacity of the foundation soil and other factors is produced. The upper structure then is led to deformation, crack, tilt or collapse. Consider this, the multi-story framed building which adoption of a separate foundation also add settlement joint and post poured joint. But these methods are inconvenient in using and construction. To solve this problem, adding post share supporting column is raised in the article.First of all, the three-phase component of the soil partials and soil compression indicator is introduced. Several formula for calculating settlement is then analyzed, it's seen that the settlement of foundation soil is concern to the geological condition, stress history stress path and time. Consider that most of the condition of pressing soil is the three-dimensional situation. At the basis of 3D settlement calculation method, the e-p curve is alternative by the e-lgp curve. Using this method, the calculating value of settlement is close to the actual value of settlement, compared to the method of foundation code, the work load is nearly the same, but from the view of the accuracy of the calculation the former is the better.In the analysis of the common work of the structure and the foundation soil, selecting the model is the most important; it influences not only the distribution of counter pressure of the bottom surface of the structure and the settlement of the base, but also the distribution of the internal forces and deformation in the upper structure and the base. So in the common effect analysis, the variety appropriate factor of the model of the foundation soil is understood, it should suitable the characteristic of site soil, it which concerned that the material characteristic, the pattern of application of load, overall geometrical relationship and environmental impact. The several common linear, non-linear elastic foundation models and elastoplastic foundation models are posted. And then, based on elastoplastic theory, the matrix formulations of elastic and elastoplastic is deduced.As a branch of structure engineering, the RC structure must obey the general regular pattern of structure engineering subject that is raised the question or requirement in real project, solved the problem through the variety measure such as investigation, statistics, experiment, researchment theory analysis and contrast, summarized the common law and reveal the mechanism, establish physical modals and mathematical formulations, determine calculative methods and construction measures, then test and verify it in real project, improve and recruit it advanced. The several concrete formulations of stress-strain relationship about single-axis and multi-axis strength are given. Several common failure criterions are compared. The steps of establishing elastoplastic constitutional equation are summarized. These provides a theoretical basis for analyzing the settlement considering the common work of the upper structure and the soil the settlement considering.The simple formula of framework models which considered that the stiffness of the upper structure is introduced. The method defined the stiffness of foundation is given. The basic relationship between the role angle and differential settlement of the beam of frame is deduced. Uses it, the differential settlement and the upper structure damage can be avoid because of the differential settlement.Analysis methods combining deferential settlement deformation with upper structure is the primary means of this paper. Using the FEM to analyze the differential settlement, the soft program Ansys is introduced, the application of substructure methods of Ansys is deduced. The various factors impacting the settlement is analyzed and compared. It's brown that to the modal of independent foundation, with the increasing of the bottom area of the foundation, the foundation settlement is increased and the plastic deformation is increased. It's not accuracy in common design that though controlling the bottom is of the foundation to control the differential settlement. With the pressure increased, the plastic zone of bottom of the base increased. And then it reached the limit of capacity. With the compression modulus increased, the settlement of the soil decreased, the curve tends to flat. In monolithically model, the results compared the method which considers the upper structure and soil work together with the method which doesn't consider that, the settlement of the base is decreased. The structure which added the supports among the columns, the settlements is further decreased. The curve is flat. So at the proper condition, adding the support, the settlement of the structure between the high framework and the low framework is decreased efficiently. The calculated method in which the upper structure and its foundation regarded as two independent units produce the great "error" compare with the reality results. The differential settlement introduces the large secondary stress in the upper structure, which is on of the most reasons leading to the frame structure cracked. To achieve the design purpose which is "adaptability , safety, economy, beauty", the author discuss the mutual affect among upper structure, foundation and foundation soil in differential frame structure building. FEM program ANSYS is used in the theory analysis. The experiment proves that the experiment result is consistent with the result of the theory analysis, which has the certainly meaning for theory analysis and project design of differential frame structure.