Research On The Design Method Of Energy Dissipating Substructure With Pier-type Connection

The pier-type connection is a common connection form of the energy dissipation structure.For the "Technical specification for seismic energy dissipation of building",the relevant provisions on substructure design are only the principle provisions.The substructure design methods in Xinjiang and Yunnan are not uniform,unreliable,and not reasonable.In this paper,the elastic design method is proposed for energy dissipating substructure with pier-type connection.According to the requirements of ultimate bearing capacity of "Technical specification for seismic energy dissipation of building",control formula of energy dissipating substructure with pier-type connection are established,the methods of taking value of each parameter in these formulas are given as well,and the additional internal force generated by the damper to energy dissipating substructure with pier-type connection can be deduced.Finally,the elastic design method and the design methods in Xinjiang and Yunnan are discussed and analyzed.The main work and conclusions are as follows:Aiming at the problem that the elastoplastic analysis results are unreliable and inaccurate,the elastic design method of energy dissipating substructure with pier-type connection is proposed.Considering the ultimate bearing capacity requirement of the substructure and the additional damping force of the damper to the substructure inarticle 6.4.2 of the "Technical specification for seismic energy dissipation of building",control formula of energy dissipating substructure with pier-type connection are established according to the balance of forces.According to the elastic design idea,control formula of energy dissipating substructure with pier-type connection was transformed reasonably and the internal force value method of substructure members under the rare earthquake was introduced.The current design method is to increase the bearing capacity of the component,which causes the seismic force of the structure to be amplified.Aiming at these problems,the method of considering the structural ductility and adjusting the bearing capacity of the members is proposed.The seismic grade is introduced,and the effects of the ductility and bearing capacity of the members are considered comprehensively to realize the design goal of the substructure as an important component.The influence of seismic grade on substructure design and construction was study and the influence of structural measures on the bearing capacity of substructures was summarized.And based on the elastic design method,there are 20 combinations combined by 4 seismic grades and 5 design criteria of substructure design and calculation value method of ultimate bearing capacity.The additional internal force of the damper on energy dissipating substructure with pier-type connection under five different arrangements are deduced.And considering the simplicity and practicability of the actual engineering application,the additional internal force of the damper on the substructure members under different arrangements are simplified and rationally merged,and the simplified additional internal force calculation formula is obtained.The results show that the simplified calculation formulas are safe and reasonable,and can be applied to practical engineering.This paper summarizes the beam,column and joint control formulas of energy dissipating substructure with pier-type connection,and gives the design and check flow and section adjustment principle of energy dissipating substructure with pier-type connection.Then the elastic design method is used to design and verifyrespectively substructure of high intensity and low intensity regions.And the elastoplastic analysis with one of the structures satisfying the control equation was carried out to verify.Finally,the design methods of the mid-seismic and large earthquakes in Xinjiang and Yunnan were analyzed and discussed.The rationality and feasibility of the elastic design method of energy dissipating substructure with pier-type connection.The results show that: 1)The elastic design method can only complete the design and verification of the substructure with only the internal force of the member under the elastic analysis.Which comprehensively considers improving bearing capacity and ductility.This method is safe and reasonable.2)The internal force value of energy dissipating substructure with pier-type connection under the rare earthquake is obtained the seismic action and the structural action caused by the gravity load under some design criterion.The mechanism of the member is clear,and the design result is reliable.3)Under each design criterion,the substructures that meet the requirements can be obtained.And the substructures under the small earthquake elastic design are the optimal.From the perspective of engineering design efficiency,it is recommended that to select the small earthquake elastic design criteria for design.4)The medium-seismic design method that only improves the design criteria does not consider the additional internal force of the damper on the substructure under the ultimate damping force and the ultimate bearing capacity requirement under the rare earthquake.This method is unreliable and unreasonable.5)The substructure is designed with the internal force of the member under the rare earthquake,which is not necessarily reliable.And the method may be after many elastic-plastic analysis,which is workload.