Bending mechanics model and value of transverse joints in precast prestressed utility tunnel

Abstract

Joints lead to the uneven distribution of structural rigidity of a precast prestressed utility tunnel (PPUT) and changes in internal forces and deformation. From research perspective, bending stiffness is important as an important indicator to evaluate the performance of PPUT joints and an important factor to evaluate the overall mechanical properties of PPUT structures. After considering the actual structural form of a transverse joint section and the characteristics of force deformation, a mechanical model that can characterize the joint section from force to failure and the corresponding analytical expressions were established using the internal force balance and deformation coordination conditions. A sensitivity analysis of the factors affecting the bending stiffness of joints was carried out using numerical simulation methods. The theoretical calculation results were compared with the numerical simulation results. Finally, according to the obtained trend of bending stiffness change, a two-stage bending stiffness method is proposed for the transverse joints of PPUT. The results of the study provide a reference for the design and theoretical analysis of PPUT.

Keywords

• precast prestressed utility tunnel
• transverse joint
• high-strength bolts
• bending mechanical model