| The cross-node design of the utility tunnel is one of the key technologies in the design of utility tunnel.This study firstly analyzes the development status of utility tunnel at home and abroad and China’s policy support for the implementation of utility tunnel construction,and analyzes the main problems faced by China in the hierarchical classification and design of utility tunnel intersections: First,the influencing factors in the current selection and design of the cross-nodes of the utility tunnel are not comprehensive,and the actual analysis process and theoretical support are lacking;Second,the cross-node structure design is multi-biased or determined by experience.The conventional octagonal prism structure not only increases the thickness of the siding and the amount of reinforcement used,but also does not meet the criteria for sustainable development of the decision-making department.According to the design status of the cross-node of the utility tunnel,the factors affecting the outlet and structural design of the cross-node of the utility tunnel were investigated and analyzed.Based on the relevant theoretical research on the cross-nodes of utility tunnel at home and abroad,the scheme of using the DHGF method to solve the problem of cross-connecting line selection and using finite element method to solve the cross-node structure design optimization problem is established.Integrate the experience of different professional design experts,the relevant specifications of utility tunnel and the actual situation of the proposed utility tunnel project through the establishment of an utility tunnel cross-connect line selection evaluation system,so that the design of the utility tunnel intersection node is more universally applicable.Sex.The evaluation system is applicable to the planning of the utility tunnel project.Before the design,the core is the comprehensive evaluation system for the intersection of the intersections of utility tunnel.The four-element integration method is used to evaluate various factors involved in the design of the cross-connect line.By substituting the actual situation of utility tunnel into the evaluation system,the advantages and disadvantages of the line plan are judged according to the actual situation of the utility tunnel project,and the appropriate optimization plan is selected to achieve the optimal design of the cross-node outlet selection.The Midas Civil finite element software was used to simulate the conventional structural design method of the integrated pipe corridor intersection.The results show that the maximum stress value appears at the corners where the bottom plate and the sidewall intersect,and the displacement of the top plate with the largest degree of deformation is only 7mm,which is much smaller than the 25 mm structural deflection specified in the specification.It shows that the conventional structural design has the problem of unbalanced internal force;and the force of the load,shearing force,etc.,which is resisted by the cross joints,increases the thickness of each wall panel,and the design lacks economy.The optimization scheme not only strengthens the load carrying capacity of the cross joints for vertical loads,but also reduces the thickness of the side walls and the bottom plate by setting up and down the sill beam and the column.The optimization scheme makes the internal force of the utility tunnel more balanced and the number of reinforcements is correspondingly reduced.Relatively reduce the investment pressure of the utility tunnel’s intersection.Through the quaternary integration method modeling and finite element method simulation,the problem of outlet selection and structure optimization encountered in the design stage of the integrated pipe corridor intersection is solved,which provides theoretical support for the design of the intersection of the utility tunnel.By combining examples,the feasibility of the method is verified,and the comprehensive design of the utility tunnel is provided for reference. |
