The 12th International Symposium on Structural Engineering STRUCTURAL DESIGN OF THE MENCIUS GRAND THEATRE Wei Liu, Dayi Ding China Wuzhou Engineering Co., Ltd. , Beijing 100053, P.R. China Abstract: For The Mencius Grand Theatre, the issues of the theatre structural design were studied in this paper. Including selection of structural form and arrangement of structure, the control of calculation indicators, the achieving of the stalls structure and the cantilevered balcony structure, foundation design and so on. According to the design objects of the structure performance, the static and earthquake were analyzed with SATWE, MIDAS and PMSAP programs. The calculation assumptions and the theater model simplification were discussed. The seismic fortification measures were also investigated to intensify the concept design. Keywords: Theatre, floor discontinuous, performance-based design, seismic fortification measures 1 INTRODUCTION In recent years, some grand theatres have been constructed in some cities of China. And some grand theatres are being planned to be designed and constructed. There are some design difficulties which are relatively typical in the theater structure design. Such as irregular plan, floor discontinuous, many split-level, cantilevered balcony, large-span roof structure and so on. In this paper, well discuss these questions with The Mencius Grand Theatre for example, in order to be referenced by the next project. 2 PROJECT PROFILE The Mencius Grand Theatre is planned to be located in the city of Zoucheng of Shandong Province, which is the hometown of Mencius. It will be a modern standard theater with 1300 seats, which can meet the needs of domestic and foreign large-scale song and dance performances. Designed with other movie theaters, commercial center, underground garage and regional power centers, the building functions are very complex. There are 4 stories aboveground, and part of the area, 2 stories underground. The auditorium building height is 25.0m, and the stage building height is 32.4m, as shown in Figure 1, the total construction area is 35220m2. The main structural form is reinforced concrete frame - shear wall structure. The roof structural form of the auditorium(40.5m40.5m) and the stage(33.3m24.3m) are both steel truss with supporting structure. The whole structure bases on the natural foundation. Beam stiffened raft is adopted for the basement part, and the single column foundation and wall strip foundation are used for the rest part. The level of the building structures security is class 2. The designed service life is 50 years. Building seismic fortification classification is B. Figure 1. Structure section plan 561 3 FOUNDATION DESIGN According to the survey report, the basement bearing stratum of natural foundation is intensely weathered granite， whose bearing capacity values fak = 500kPa, and Es1-2 = 45MPa. As to the beam stiffened raft, the width of the floor beam is 0.6m, and the height is 1.5m. The thickness of the bottom plate is mainly 450mm, several is 600mm. Bottom elevation of the floor beams in the stage and auditorium part is -12.78m. And in the neighboring parking garage part is -8.08m. The basement wall at the border must bear the soil pressure caused by the higher elevation raft. No expansion joints lie in the basement, but post-poured strip width 800 - 1000mm will be set every 30 - 40 meters. Post-poured strip settings are shown in Figure 2a), other layers are the same. The single column foundation and wall strip foundation are used for the rest part. The differential settlement is controlled by 0.003L. Taking into account the beneficial effects on subsidence deformation, the single column foundation and wall strip foundation land at -4.000m, which is the same raft foundation bearing stratum. In the auditorium area, the stalls cause the arc column grid, and the basement of the regional power centers cause the partial column or the column pulling. All these lead to the poor regularity of the basement column gird. Foundation beams are set at the outer edge of the basement board, to unify the basement floor reinforcement. Based on previous experience, the crack width is not necessary to be checked for foundation beam and plate. Anti-floating design water level is 5.1m underground. Anti-float calculation should be done for stage area and auditorium area respectively, in order to meet the requirements of the local anti-floating. 4 MAIN STRUCTURE DESIGN FEATURES Acoording to GB 50011-2010 code 10.1.6, a certain number of reinforced concrete shear wall should be set between hall and auditorium, and auditorium and stage, in order to strengthen the lateral stiffness. Seismic walls are set up around the stage, and also axis Y direction wall of the side stage, in order to strengthen the stiffness where there is no floor. Combined with the vertical transportation, the shear walls are also set up in the stairway surroundings. In addition, shear walls also lie in