A Comparative Study Of High-rise Building Structural Scheme

An actual 27-story building located in Beitaipingzhuang in Beijing is studied in the thesis. The reinforced concrete frame-core structure and steel frame-concrete core structure are adopted; these two structural systems are analyzed on static, dynamic and earthquake behavior.The analytical results show that these two structural systems are all suitable for the project. The natural vibratory period is 2.9s for concrete structure and 2.7s for composite structure; the total weight (W) is 621000kN for concrete structure and 497880kN for composite structure; the total base earthquake shear force is 20642kN(X direction, correspond with 3.32%W) and 20182kN(Y direction, correspond with 3.25%W) for concrete structure, 22377kN(X direction, correspond with 4.49%W) and 17890kN(Y direction, correspond with 3.59%W) for composite structure; the maximal displacement between stories under earthquake is 1/1050(X direction) and 1/882(Y direction) for concrete structure, 1/1253(X direction) and 1/718(Y direction) for composite structure; the structural area is 1708.56m2 for concrete, 1419.68m2 for composite structure; construction duration of superstructure is about 168 days for concrete structure and 112 days for composite structure; for composite structure, less structural area will give more income, less time will give less loan interest and more rent, the general economic benefit is almost the same after considering these factors, the direct cost of the composite structure is 13.4 million Yuan more than that of the concrete structure before considering these factors.A general economic benefit comparison between these two structure systems has been given in the thesis when the building total height is from 80m to 180m. The weight of the composite structure is 65%~80% of that of concrete structure; the structural area of the composite structure is 75%~90% of that of concrete structure; the construction time of the composite structure is 2/3 of that of constructing concrete structure; the general economic benefit is almost equal between these two options when the building height is about 100m, the composite structure is better than the concrete structure when the height is beyond 120m. The anti-seismic designs of high-rise buildings have been discussed in the thesis, and the relationships among the conceptual design, calculation design, and detail design are explained.The equivalent load values when partition walls act on two-way slabs has been discussed, an approximate formula to calculate deflection of reinforced concrete beam with ordinary two flexibility supports has been understand in the thesis; a utility program in MathCAD to calculate a steel-concrete composite beam at two simple supports has been given, which may be used very convenient for engineers.The study results of the thesis will be valuable as reference when dealing with similar projects and structural members.