Design Of Over-Long Reinforced Concrete Basement Without Permanent Joint Considering The Constraint Acts

With the increased demand of urban underground space, large basement is so common. The cracks lead by the ultra-long structure have always been an engineering problem, and until now, there is no fundamentally reliable solution to this. Setting expansion joints for every certain distance is a universal method in the earlier design, but the resulting joint leakage problem is also an extremely difficult problem. Especially in the Jiangsu and Zhejiang region, which is rich in groundwater resources with high the groundwater levels and head pressure, leaking problems are often temporarily solved by blocking the cracks. However these joints often will leak again as time go by. So, the fundamentally way to solve this problem is to use a no-permanent-joint-design method.This paper analyses the formation mechanism and the harms of the large-scale concrete temperature cracks, and reviews the literature at home and abroad about engineering practice and research of the relative field. Then, the paper integrates the aspects of concrete materials, structure measures, construction measures and proposes a no permanent joint design method of super-long reinforced concrete basement structures in consideration of the role of constraint Component.This thesis mainly studied the influence of the constraint body on the Thermal Strain distribution of the mass concrete floor and long wall; And it put forward the concept and the calculation method of the degree of constraint; then it summarizes the influencing factors of the degree of constraint, such as the diameter of the pile, pile spacing, the lateral stiffness of the pile and pile backplane connection. At last, the paper used the ABAQUS software to simulate the Thermal Strain distribution of the long concrete basement side wall due to cooling in the case of different pile spacing. It can be found from the analogous that the Thermal Strain distribution of sidewall under different conditions differs a lot. Therefore, the constraint component can make the large structures into smaller ones, so that the Thermal Strain of the concrete will be controlled, in this way, the cracks been controlled and there is no permanent joint in that long structure.Above all, this thesis has successfully provides reference for the design and construction of long reinforced concrete basement structure.