Research On The Design Optimization Of Deep Foundation Pit Diaphragm Wall And Interior Bracing Composite Support

With the massive construction of high-rise buildings,super high-rise buildings,subway,and tunnel,The direction of foundation pits are developed to wider and deeper,thus some accidents was happened in the process of excavation and supporting,causing casualties and the destruction of the environment.However,over conservative of design can lead to the materials were wasted,also can bring certain difficulty to the site construction.Therefore,research the internal support level spacing of deep foundation pit to optimize and the demolition process that can improve the stability of foundation pit,and reduce the influence of excavation to surrounding environment,and can also provide convenient for construction.In this paper,taking dongfeng road and wenhua road pass through the tunnel under the engineering background in zhengzhou,used software FLAC^3D,internal support of the foundation pit horizontal spacing were optimized for K0-30 section,and the numerical simulation of the internal support demolition process were studied,the stress and strain of law to composite wall were researched and studied under different project conditions,combined with the measured data to research and analyze,mainly making some works in the following several aspects:（1）Research on optimizing of foundation pit internal support horizontal spacing: simulated inner support for horizontal spacing to equal and unequal two kinds of arrangement by software FLAC^3D,in foundation pit excavation and supporting process.In the foundation pit stability,studied on the changing rule that retaining structure horizontal displacement and vertical displacement and horizontal stress and vertical stress and of the support axial forces.In the surrounding environment stability,studied on the changing rules for ground subsidence to the back of the wal.（2）Research on the method for foundation pit internal support demolition opportunity with surrounding environment influence in harmony: simulated the demolition process of the foundation pit internal support by software FLAC^3D.Research on the changing rules that the support structure for horizontal displacement,vertical displacement and each of internal support in the demolition process,compared and analyzed the simulation value with measured value under different project conditions.At the same time,plastic area were analyzed in the demolition process.（3）Research on the changing rules of the composite wall for stress and strain under different conditions: first,a brief of introduction to composite wall and its construction condition.Then,simulated the changing rules of that composite wall under different conditions of horizontal stress and vertical stress,horizontal displacement and vertical displacement by software FLAC^3D.