The Control And Effects Of Subgrade Deformation Of Single-layer Steel-frame Mill Building In Soft Soil Area

In soft soil area, the interaction of subgrade deformation and superstructure is a very important matter must taken into consideration. Presently, the control of subgrade deformation is carried out by enactiving the allowable value to avoiding or minishing its effects in design stage. For existing building, however, subgrade deformation usually exceeds the allowable subsoil deformation that is anticipated in design phase because of many reasons, which is especially serious in soft soil area. And this produces additional stress not considered in design stage and reduces the reliability of superstructure. Therefore, by establishing controllable method of subgrade deformation and measuring ground actual displacement in exiting building, effects of subgrade deformation are well controlled and the structural safety is effectively ensured. Comparatively saying, the control of subgrade deformation in existing building has a more important engeering meaning.On the base of on-the-spot survey and theoretical analysis, systematic research to a monolayer steel structure on Pylon factory of Bao-steel Stock Ltd is carried out. The paper analyzes the influence of subgrade deformation on the workshop and establishes analytical method and controllable standard of effects of subgrade deformation in soft soil region. The main research content and results are concluded as follows:1. The paper investigates detailedly the usage condition of the factory and subgrade deformation course and uses the long-term measuring settlement data to analyze the law of subgrade deformation in soft soil area and main influent factors.2. The paper analyses comprehensively spatial effects of foundation deformation using ANSYS finite element method including foundation horizontal deformation, settlement and rotation's influence on the whole structure. In this way, influential range and position on the condition of different foundation deformations are mastered, along with different structural members' unit effect.3. The paper analyses similarly the effect of foundation deformation using planar-analysis method which is usually adopted practically, and points out the diffenrence by contrasting the results of spacial model and those of planar model, and analyses main structural member which play a important role in different foundation deformations.4. The paper establishes planar structural analytical method which is equvalent to spatial structural analytical method by comparing both of the results. Based on planar structural analyticalmethod, spacial effects of foundation deformation are acquired approximativly ,which provides a practical method.5. The paper establishes safety control criterion of subgrade deformation of steel structure workshop in soft soil region in terms of design criteria of subgrade deformation in soft soil region and the classification standard on reliability of steel structural member, which offers a security of structural safety.In the paper, the research content and results provide a wholly analytical and controllable method for safety control of steel structure factory in soft soil region. And the method monitors structural safety at any moment by measuring the deformation, so it provides a brief and practical way of safety control on workshop. Moreover the basic idea and research method in this paper offer a important reference to other types of monolayer workshop structure.