Study On The Improve Calculation And The Optimization Design Research Of Pre-stress Ancho Lattice Beam

The development of deep foundation pit support technology has been promoted bythe process of urbanization, with a variety of methods having emerged at the same time.The technology of lattice beam shotcrete and rock bolt support has been being widelyused, because of its advantages, such as convenience of construction, taking small spaceand economy and security. At present, there are a lot of researches about this timberform at home and abroad, in which many the studies rely in the anchor or anchor ofpre-stressed, both in the theoretical aspects and the test ones, while the research aboutlattice beam is little. Theoretical system, not only in qualitative or quantitative, has notformed. Lattice beam is a very important part of the beam shotcrete and rock boltsupport system. It has direct relationship with the quality of the whole support system‘sworking conditions. The mechanical character of lattice beam is complicated,influenced by the factors of Ground conditions, anchor action and so on. Designersusually design lattice beam according to structural design requirements and experience，calculating with the structure of the simple beam and continuous beam. However, thesemethods are not entirely suitable for lattice beams, with obviously unreasonable aspects.Therefore, the research on lattice beam is very necessary and urgent.The improve improved method of Winkler theory model of the lattice beam: Thispaper introduces modified Winkler foundation model method with horizontal forcebeing taken into account, both of which are based on the Winkler common method thatconsiders the interactions of beam and foundation. Programming with mathematicalsoftware Matlab, this paper calculates and analysis the changeable discipline offoundation and beam stiffness, and analysis the applicability of several improved latticebeam calculation methods. Through comparing the measured values with the originalWinkler methods and improved Winkler, which the foundation model with horizontalforce has been taken into account, verified the advanced nature of improved method.Lattice beam is being monitored in the deep foundation pit of Engineering example.After longitudinal beam having been chosen as the study object, the internal force hasbeen counted, through measuring the strain of the beam. The strained condition oflattice beams in the project has been simulated by the structural analysis software ofANSYS. The interaction between beam and soil has been truly simulated and the space function of beam has been also visually reflected. In this paper, the model received areasonable simplification and boundary treatment, having simulated excavation in thecourse of seven different beam conditions. The feasibility of this method is verified, asthe results through calculating and measuring having minimum differences.Optimized lattice beam design: This paper introduces the lattice beams and theevolutionary forces simplified algorithm strategies applied to lattice beamoptimization algorithm designed to explain the lattice beam design methodsimplifies the calculation of internal force process, the establishment of a deepevolutionary strategy based on pit supporting structure design optimization of themathematical model. Evolution strategy with lattice girder force method is applied tosimplify the design of foundation pit structure design, to ensure safe and reliablesupporting structure under the premise can choose a reasonable lattice beam size, areasonable reinforcement, optimizing the project cost, to be ideal optimization results.By means of the study on lattice beam shotcrete and rock bolt support, this paperhas proposed the design and calculative methods for Qingdao region, and has givensome suggestions for other types of ground conditions. The design and calculation onthe lattice beam shotcrete is moderately valuable, especially the software of ANSYShaving been applied. Raised by this study lattice beam evolutionstrategy optimization method, whilesimplifying theuseof force lattice beam lattice beam algorithmto optimize the design also has some practical reference value.