Seismic Design of Building Structures
Chapter 1 Introduction
1.The types and caus of earthquakes （地震的类型和成因）
Man-made earthquakes, explode, mining operation, major project construction (such as rervoir) Natural earthquakes
Tectonic earthquake, tectonic activity of lithosphere
V olcanic Earthquakes, volcanic eruptions
2.Some terminologies about earthquakes, focus, epicenter, focal depth, epicenter distance and
isoismal line (地震的一些相关术语，如震源，震中，震源深度，震中距，等震线)
Focus, center or hypocenter, The point where the ismic motion originates
Epifocus or epicenter, The projection of the focus onto the surface of the earth
Focal depth, The depth of hypocenter below the epicenter
Epicenter distance, The distance from the epicenter to the point of the obrved ground motion Isoismal line一次地震中，在受影响的区域内，烈度相同的区域的外包线
3.The classification of ismic waves. (地震波的类型)
Body waves include Primary Wave (P wave) and Secondary Wave (S wave)
Surface waves include Rayleigh wave (R wave) and Love wave（Love wave）
最新网络红歌4.The esntial factors of ground motion. （地震动的三要素）
Magnitude/amplitude（幅值）Frequency/spectrum （频率）Duration （持时）
5.The concept of earthquake magnitude and intensity and the difference between them. (震级与烈度的
概念以及它们之间的区别)
The earthquake magnitude means the energy relead in an earthquake
Earthquake intensity is an indication of the verity of ground shaking at a specific site which is ba
d on the obrve defects of an earthquake and a qualitative asssment of the damage that caud
There is only one magnitude for an earthquake, but maybe many intensities for different locations.
Becau intensity scales are subjective and depend upon social and construction conditions of a country, they need revision from time to time. Regional effects must be accounted for.
6.Three-level ismic fortification objectives and Two-pha ismic design method. (三水准抗震设防
与两阶段设计)
The first level: No damage under minor earthquake (小震不坏)
The Second level: Repairable damage under moderate earthquake (中震可修)
The third level: No collap under large earthquake (大震不倒)
Pha1: By the elastic analysis, the carrying capacity of the structure is checked under the fundamental combination of effects of ismic action of minor earthquake and other loads, and the elastic ismic deformation is checked under the action of minor earthquakes.
Pha2: The elastoplastic deformation is checked under the action of rare earthquake.
The structural design through the first pha can satisfy the requirements of the first ismic fortification level1. The structural design through the cond pha can guarantee the ismic fortification level3.
The Seismic Fortification Objective2 is guaranteed by constructional measures(构造措施)and conceptual design(概念设计).
7.The meanings of Minor, Moderate and Large earthquake. (小震，中震，大震的含义)
Frequently occurred earthquakes with an intensity of less than the fortification intensity of the region Earthquakes equal to the fortification intensity of the region
Rare earthquakes with an intensity higher than the fortification intensity of the region.
8.Three aspects of ismic design of buildings. (建筑抗震三个层次的内容)
Seismic conceptual design, ismic computation, construction measures
9.In Chine Code for Seismic Design of Buildings, what factors are related to height limits of
风车制作
buildings? (根据中国抗震设计规范，哪些因素与建筑物高度限值有关？)
Site condition, fortification intensity of the region, structural type, using requirements, economy issues
10.Why the resisting members should be placed on the perimeter? （为何抗侧力构件应当布置在周
边？）
Increa the moment arm, thus increasing the lateral stiffness and carrying capacity for horizontal load 11.From the ismic view, what characters should be the desirable aspects of building configuration on
the overall form? (从抗震角度来看，建筑物理想的总体造型有什么特征？)
The desirable aspects of building configuration are simplicity, regularity, and symmetry in both plan and elevation.
The properties all contribute to a more even distribution of earthquake forces in the structural system.
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12.Illustrating the attributes of the optimum ismic configuration and giving the reasons. (说明建筑物
抗震设计的最优外形特征，并解释其原因)
1. Low aspect ratio (minimize tendency to overturn)
2. Equal floor heights (equalize column/wall stiffness)
3. Symmetrical plan shape (reduce torsion)
4. Identical resistance on both axes (balanced resistance in all directions)
环控系统>猪的守护神5. Uniform ction and elevations (eliminate stress concentrations)
6. Seismic resisting elements at perimeter (maximum torsional resistance)
7. Redundancy (toleration of failure of some members)
8. Direct load paths (less stress concentrations)
13.According to Chine Code for Seismic Design of Buildings, what are the requirements for ismic
structural system? (根据中国的抗震设计规范，对于结构体系抗震方面的要求有哪些？)
1. It shall have a clear analytical model and reasonable path for ismic action transfer.
2. It should have veral lines of defen against earthquakes. It should avoid loss of either earthquake resistance capacity or gravity load capacity of the whole system due to damage to part of the structure or members.
3. It shall posss the necessary strength, adequate deformability, and better energy dissipation ability.
4. It should posss a rational distribution of stiffness and strength, avoid weakening of some parts of the structure due to local weakening or abrupt changes; avoid appearance of extremely large concentration of stress and plastic deformation; when weak parts do appear, measures should be taken to enhance their earthquake resistance capacity.
5. It should have similar dynamic characteristics in the direction of individual primary axis.
Chapter 2 Site and Subsoil
1.The ismic effect of structures influenced from the construction site. (场地对结构地震效应的影响)
High-ri buildings founded on soft soils were more damaged than the similar buildings founded on rock.
The ismic waves propagated in the lithosphere have many contents of frequencies. The period which is related to the maximum value in the vibration amplitude is termed as Predominant Period(卓
越周期).
If the frequency of the structure is near to the one of ismic wave, the rious damages can happen in the structures. (resonance, 共振)
The ismic effect of soil depends mostly on the thickness of overlaying soil(覆盖土层厚度), shear-wave velocity (剪切波速)and impedance ratio (阻抗比) of soil.
The thickness of overplaying soil and shear-wave velocity mainly influence the frequency properties of ismic wave
2.The categories of sites and how to classify them. （场地的类型及划分原则）
Construction sites shall be classified into four categories according to the type of site soil and the overlaying thickness at the site, and should also comply with the table2.3.
3.How to check the bearing capacity of natural subsoil. (如何验算地基土的抗震承载力)
Except the building listed above, the bearing capacity of natural subsoil and foundation should be checked for earthquake resistance by the following equation: f aE=ξa f a (ξa≥1)
4.The cau of soil liquefaction. (砂土液化产生的原因)
p25 During strong earthquake shaking, a loo saturated sand deposit (饱和松散的砂土) will have a tendency to compact, which will result in a decrea in volume and increa in the pore water pressure.
If the pore water pressure increas to overburden pressure, the effective pressure will be zero. Since the shear strength of soil is directly proportional to the effective stress, the sand will not have any shear strength and is now in a “liquid” state, which is called soil liquefaction.
5.The procedure of discrimination for the liquefaction potential. (砂土液化的判别步骤)
Preliminary Discrimination
Generally, the discrimination of the potential of liquefaction of the saturated soil and adoption of methods to prevent liquefaction need not be considered when intensity is Ⅵ, but for Type B buildings which are nsitive to the ttlement caud by liquefaction, the subsoil can be treated as intensity Ⅶ.
When the intensity is Ⅶto Ⅸ, for type B buildings, discrimination of the potential of liquefaction and adoption of relevant methods may be considered using the specifications of the local fortification intensity.
If one of the following conditions is satisfied, saturated sand or silt may be preliminarily discriminated as non-liquefiable soil, or effects of liquefaction need not be considered…
(1)If the geological period of the soil is the Pleistocene of the Quaternary period (Q3) or earlier, the
soil may be considered as non-liquefiable when the intensity is Ⅶor Ⅷ.
(2)If the clay particle content (particle diameter less than 0.005mm) of slit (粉土) is not less than 10%,
风雨中抱紧自由13% and 16%, when the intensity is Ⅶ, Ⅷand Ⅸrespectively
(3)For buildings resting on natural subsoil, effects of liquefaction need not be considered when the
thickness of the non-liquefiable overlaying layer (上覆非液化土层厚度) and the depth of underground water level （地下水位深度）comply with one of the following conditions:
Standard penetration tests
6.The meanings of liquefaction index. (液化指数的含义)
For the subsoil with liquefaction-potential soil layers, its category of liquefaction shall be classified according to the liquefaction index
Chapter 3 Respon Analysis of Engineering Structures
1.The meanings of ismic respon spectrum. (地震反应谱的含义)
The relationship between maximum absolute acceleration Sa of SDOF system and its period T
2.The mode shapes of MDOF systems. (多自由度体系的振型)
The structural respon can be decompod to many independent coordinates. The independence of coordinate axis is the orthogonality.
3.The procedures of mode-superposition spectrum method. (振型分解反应谱法的基本步骤)
4.The application condition and procedure of ba shear method. (底部剪力法的适用条件及步骤)
(1)The structural height is less than 40m;
(2) The deformation of the structure should be shear type with evenly distribution of mass and
stiffness in the vertical direction.
(3) Approximately SDOF system.
5.What kind of structures should be analyzed including vertical ismic action. (哪些结构需要考虑竖
向地震作用)
Tall buildings (Intensity 9), large-span or long cantilever structures (Intensity 8 and 9)
6.The meanings of reprentative value of gravity load. (重力荷载代表值的含义)
p69 When earthquake happens, the variable loads acting on structure often does not reach their characteristic values. In ismic design, the reprentative value of gravity load is the addition of characteristic value of weight and combination values of relevant variable loads.
7.The contents of ismic checking of structures. (结构抗震验算的内容)
Strength checking and deformation checking
(1)The deformation checking of structures under frequently occurred earthquake is to avoid the
damage of non-structural members.
(2)The strength checking of structures under frequently occurred earthquake is to avoid the damage of
structural members.
(3)The deformation checking of structures under rare occurred earthquake is to avoid the collap of
structures.
The requirement of “Repairable damage under moderate earthquake”is guaranteed by ismic concept design and construction measurements.
Chapter 5 Seismic Design of Concrete Structures
1.The basis and meanings for ismic grading of RC structures. (混凝土结构抗震等级划分的依据及
意义)
grading of reinforced concrete structures is a practical scale governed by earthquake design philosophy.
respect to ismic intensity, types of structural systems, and the overall height of buildings, reinforced concrete building structures are classified as four ismic grades.
2.The distribution of ismic action among lateral force-resisting members. (地震作用如何在各抗侧力
构件之间进行分配)
Seismic action distributes among columns according to the stiffness of each column.
3.The difference between inflexion point method and D-Value method. (反弯点法与D值法的区别)
Assumption of inflexion point method：
(1)The linear stiffness of beam is infinity
(2) The zero moment point of bottom story is on the 2/3 height of the column from the ba.
4.The ductility design methods of RC frame structures. (钢筋混凝土框架结构的延性设计措施)
1. Strong Columns with Weak Beams: Plastic hinges should appear at beam ends as much as possible;
2. Strong Shear Capacity with Weak Flexure: Avoid the shear damages of beams and columns and
ensure the ductility of members and structures;
养鸡3. Strong Joints and Strong Anchoring: Avoid the damages of joints and anchoring failure of
reinforcements.
5.The classification of shear walls. （剪力墙的类型及其特点）
Integrated Wall,
Integrated Wall with small opening
Coupled Walls
Wall Frame
6.The layout of shear walls in frame-shear structures. (框剪结构中剪力墙力墙布置原则)
(1)Locations where the large vertical loads are applied；
There are large axial forces at the locations. The shear walls in the locations can avoid unfavorable eccentric tension.
(2) Ends of Buildings;
To provide more torsional stiffness.
(3)Stair and Elevator room ；
Decread stiffness due to the large openings in the floor.
(4) Reentrant corners
To reduce stress concentration.
手机突然充不上电Axial compression ratio
The influence of axial compression ratio on the shear bearing capacity:
Small axial compression, the shear bearing capacity of core concrete in the joints will increa with the increa of axial compression ratio；
Large axial compression (0.6~0.8), the shear bearing capacity of core concrete in the joints will decrea with the increa of axial compression ratio;
The influence of axial compression ratio on the ductility:
The increa of axial compression will result in the decrea of the ductility.
