建筑结构抗震设计原理 课后思考题.docx

思考题建筑结构抗震思考题1. 地震震级和地震烈度有何区别与联系？2. 怎样理解小震、中震和大震？3. 为什么抗震设计时要考虑场地影响？怎样考虑？4. 影响土层液化的主要因素是什么？ 土层液化会造成那些后果？5. 根据表中数值计算场地等效剪切波速，并判断场地类别。土层厚度2.25.88.24.54.3vs(m/s)1802002604205306. 结构抗震计算有几种方法？分别在什么情况下适用？7. 解释地震反应谱与设计反应谱之间的关系。8. 什么是地震系数和地震影响系数？它们有何关系？为什么软场地的特征周期大于硬场地的特征周期？为什么远震的特征周期大于近震的特征周9.期？9. 设计反应谱由几段组成？试叙述各区段的特点。10. 计算地震作用时结构的重力荷载怎样取值？11. 怎样进行结构的振型分解？12. 如何根据各振型的反应求结构的总反应？其依据是什么？13. 如何考虑不同类型建筑的抗震设防？14. 如何确定结构的薄弱层？15. 哪些结构需考虑竖向地震作用？16. 抗震设计为什么要满足“强柱弱梁”、“强剪弱弯”、“强节点弱杆件”的原则？如何满足这些原 则？17. 对水平地震作用的弯矩可以调幅吗？18. 多高层钢筋混凝土结构抗震等级划分的依据是什么？有何意义？19. 框架结构在什么部位应加密箍筋？20. 怎样理解多层砖房震害的一般规律？21. 在多层砌体中设置圈梁和构造柱的作用是什么？画出构造柱与墙体连接构造。22. 怎样理解底部框架结构的设计原则？23. 多高层钢结构梁柱刚性连接断裂破坏的主要原因是什么？24. 进行钢框架地震反应分析与进行钢筋混凝土框架地震反应分析相比有何特殊因素要考虑？25. 抗震设计时为什么支撑斜杆的承载力要折减？26. 中心支撑与偏心支撑钢框架抗震设计应注意哪些问题？PARTI QUESTIONSPART II CALCULATION AND SEISMIC DESIGNChapter 11. How many sorts of earthquakes depending on the focal depth and the courses of earthquake respectively?2. What are the main features of an earthquake acceleration record, and what roles are they in seismic design?3. What differences between earthquake magnitude and intensity, and which index is used in seismic design of building?4. What earthquake design philosophy is accepted in China? How to realize these ideas in seismic design?Chapter 25. How many categories are classified in seismic design according code for seismic design of building (GB 50011-2001) And what factors are dependent on?6. Description briefly the steps of calculation of natural fundamental seismic capacity.7. Briefly introduce the phenomena of soil liquefaction How to determine the liquefaction Index?8. What damages may be occurred on ground surface and buildings?9. How to mitigate of soil liquefaction hazard?Chapter 310. Description briefly the steps of Mode Analysis Method in calculation of earthquake action of seismic design of building.11. Why the additional horizontal seismic action applied top of building should be considered in Base Shear Method?12. How many methods are normally accepted in calculation of earthquake response?13. Introduce briefly about the numerical integration for calculation of earthquake response.14. What is the generalized-coordinate approach?15. What are generally included in response analysis of a MDOF system?16. What similarities and differences in the calculation between static analysis and dynamic analysis respectively?17. What is the Base Shear method? And what assumption should be considered?18. What is the seismic effect coefficient curve?Chapter 419. In building configuration, what main factors should be consideration?20. Why design characteristic of redundancy and detailing connection should be considered carefully in seismic design of building?21. What is a desirable aspect of building configuration?22. In summary, what are main factors of the optimum seismic configuration?23. Why torsion irregularity in plan should be restricted strictly?24. In Chinese Code for Seismic Design of Buildings, what additional requirements are specified if irregularities defined is large than limit?25. What requirements should be take into consider in general seismic structural system?26. What effects of nonstructural components on structural system?Chapter 527. Introduce briefly about the principle of “strong column-weak beam”，and How to realize it in column design?28. Introduce briefly about the principle of “strong shear and weak flexural”.29. Introduce briefly about the principle of “strong joints and weak member”. And how to design beamcolumn joint?30. Indicate what main failure modes for cantilever structure.31. What basic assumption and analytical models for dual system?32. What is the limitation on cross-section dimensions of framed beams?33. What is the limitation of axial compression ratio of column in frame structure with seismic grade 1?34. What is the limitation of story drift for reinforce concrete frame structure system and shear wall system respectively in site of intensity grade VII?35. Why the boundary elements should be set in a structure wall?Chapter 636. How many main structural types of masonry buildings? And what are they?37. What are the design criteria for multi-story masonry?38. What configuration of structural system of multi-story masonry building with framed first one/two stories is it?39. What is the principle for the distribution of horizontal seismic action?40. Indicates the calculation steps in calculation of multi-story building.41. What are building height limitation, numbers of stories and minimum thickness for the multi-story with ordinary brick in site intensity VII respectively?42. Why the location dimension limitation should be considered in seismic design for multi -story masonry building?43. Why reinforce concrete constructional column and ring beam should be set in multi-story brick building?44. What is the value of horizontal seismic effect coefficient in site of intensity grade VII, grade VIII and GradeIX?Chapter 745. What are mechanical properties of structural steel in seismic design?46. What are normal failure modes for steel structure and steel members?47. Indicate briefly about requirements for arrangement of steel structure system.48. What is the height limitation and height-width ratio for steel structure with braced frame system in site of earthquake intensity grade VII?49. What is the idea failure mode for braced frame system?50. Why several lines against earthquake attack should be set in seismic design?51. In beam-column joint, which one is suggested in seismic design, column through type or beam through type?52. What is basically assumption for single story large span workshop in calculation of earthquake action?53. What is the guidance for distribution of earthquake load in longitudinal direction of steel workshop?Chapter 854. What is the concept of active control and passive control in building seismic design respectively?55. How many types for isolation system? And what are their differences with each other?56. How many kinds of damper are used in increasing damping ratio of building structure?57. What effect of increasing damping ratio of building structure?What differences are in force-displacement relationship for hysteretic damper and velocity-dependant58.damper?58. Briefly introduce the applications of one type of damper.59. Briefly introduce the applications of one type of isolator.PARTI QUESTIONSPART II CALCULATION AND SEISMIC DESIGNExercise 1The soil profile at a site is shown in table 1. Determine the appropriate soil type.Table 1 Data of soil exploration at siteBottom depth of soil layer (m)Thickness of soil layer (m)Soil profile nameShear-wave (m/s)8.58.5Soft Clay13532.824.3Very soft silty clay20035.110.8Sand24043.38.2Fine sand33068.825.5Gravelly sand550Exercise 2A three-story reinforce concrete frame section is shown in Figure 1. Two columns have same cross with b=0.30m and h=0.45m and the height for every floor is same as 3.3 meters. The mass of every floor is concentrated at floor lever, and with same value as 12000kg for 1st floor and 2nd floor, and 6000kg for 3rd floor. The modulus of concrete is E=2.5*1010Pa. Please determine the Mode Shapes, Periods and Participation Factors of this three-story Frame.Figure 1 model for calculationExercise 3A 5-story reinforce concrete building is located at site of category III which design seismic in group 1. The seismic zone of intensity for design is VII. After dynamic analysis for this building, five modes and corresponding periods, participating factor are given and shown in Figure 2. The damp ratio of this frame is 0.05.1. Calculate the standard horizontal seismic actions at each story under frequent-occurring earthquake by base shear method2. Calculate the standard horizontal seismic actions at each story under frequent-occurring earthquake bymode analysis method.3. Compare two results and briefly introduce the effect of additional horizontal seismic action applied at the top of the building in base shear method.Figure 2.Five modes and corresponding periods, participating factorExercise 4Seismic design of a 5-story reinforce concrete frameA 5-story office building, structured in reinforce concrete frame, located in Shanghai. Seismic zone of intensity for design is VII, site of category IV and design seismic in group 1. The strength of concrete for beams and columns is grade C30; main longitudinal reinforcing bars are steel grade HRB335, transverse or stirrup reinforcing bars are HPB235. The plane and section of the structure are shown in Figure 3. Check seismic resistance of the axis frame in transversal direction.1. Calculate lateral seismic actions under frequent-occurring earthquake (the fundamental period of frameis 0.6sec).2. Drawing figures of seismic force, story shear forces and moment.3. Calculate elastic story drift and make the drift diagram.Figure 3 Plane and section of the building, and the model for analysisExercise 5seismic design of a six-story masonry buildingThe six-story masonry, height of first story is 3.85 m (from foundation), and other story is 2.8m high. Structural plan is seen as fig 4. The floors and roof are pre-cast cored slabs. The material of the upper stories is the multi-hole brick and the grade is MU10; and the mortar grade is M10 in first story, M7.5 in second and third story, M5 in others. Dimensions of the doors and windows are seen as Fig 4. Seismic intensity is 训，and design earthquake is in group II, at site of categoryII.The representative values of gravity loads of stories are:G6 = 3345.2kN, G5 = 3785.9kN, G4 = 3785.9kN, G3 = 3785.9kN, G2 = 3785.9kN, G1 =4245.2kN1. Calculation of horizontal seismic action.2. Check seismic capacity of walls in axis and between axis A and B axis .Figure 4 Structural plan of the masonry buildingExercise 6seismic design of a single-story steel workshopA single-story steel workshop with one bay is located at site of category II with design earthquake in group I.And the Seismic intensity is 训.The calculation model is shown in Fig.5. The two steel columns are same asE 公 1* H450*50*12*20 and the moment of inertia5.315*108mm4. The steel property is Q235 with,Please calculate the standard value of horizontal seismic action of this workshop and check the capacity of this column under frequently occurred earthquake.Figure 5 Calculation model for a single story workshop with one bay