建筑结构抗震设计（Seismic design of building structure）

1、建筑结构抗震设计（Seismic design of building structure）What are the 1 main factors, effects of soil liquefaction: geological time, viscous soil particle content, the thickness of the overlying non liquefied soil, groundwater depth, soil compactness, earthquake magnitude and intensity. The three elements of s

2、oil liquefaction is silty sand, saturated water, vibration intensity. Therefore, in the soil clay, fine degree is deeper, the underground water level is higher, the earthquake intensity is higher, the soil more susceptible to liquefaction.2, what is the seismic response spectrum? What is the design

3、response spectrum? What is the relationship between them: the maximum acceleration of earthquake response of single degree of freedom elastic system and its vibration cycle curve called seismic response spectrum (acceleration), Sa (T) said. Design response spectrum: considering different structural

4、damping and various influence factors on site earthquake response spectrum, and specialized research for structural seismic design response spectrum, often with a (T), the relationship between the two is a (T) = Sa (T) /g.3, what is the time history analysis? How to use the time history analysis of

5、earthquake wave? The seismic acceleration curve, direct input to the design of the structure, then the numerical integration of the motion equation of the structure, the seismic response of structures can be obtained in the whole range of. Should be consistent with structural calculation, field cons

6、istent with the seismic intensity of ground motion records or artificial wave curve, at least 2 actual earthquake records and one artificial acceleration time.What is 4, in the multi story masonry structure arranged in the beam? Set role: to strengthen the connection of vertical and horizontal wall

7、beam, increasing the whole floor, increase the stability of the wall, together with structural column effective crack constrained wall development, improve the seismic capacity of the walls, effectively resist due to earthquake or other reasons caused by the uneven settlement of foundation damage to

8、 housing.5, why should meet the seismic design of strong column and weak beam, strong shear weak bending and strong joint and weak member principle? How to meet these principles? Strong column and weak beam can effectively prevent the failure mechanism of column hinge, ensure the structure is not th

9、e overall collapse under strong earthquake; strong shear weak bending which can effectively prevent the occurrence of brittle failure, the structure has good energy dissipation capacity; strong node weak component, beam and column nodes constitute the basis for the whole the structure, in any case s

10、hould make the connection stiffness and strength is greater than the component stiffness and strength.1, natural earthquake are mainly tectonic earthquake and volcano earthquake. 2, with the fastest speed of seismic wave propagation in longitudinal wave, surface wave time, the slowest. Three element

11、s 3, ground motion peak, spectrum, duration. 4, the seismic effect of multi-layer soil mainly depends on three basic factors: soil covering thickness, shear wave velocity and the damping ratio of the three dynamic characteristics of structure is 5, since the rock vibration period, vibration mode and

12、 impedance ratio:. The three elements, the characteristics of 6 ground motion amplitude, frequency, duration. 7, according to the framework of the failure mechanism can be divided into: the beam hinge mechanism, column hinge mechanism. The definition formula of pressure ratio of 8, column: n=N/ (fcA

13、c). 2, the site is determined according to the comprehensive analogy soil equivalent shear wave velocity and the thickness of the site. 3, general engineering structures are under damped state. 4, seismic amplitude and seismic response spectrum value is bigger. 5, when the structural period is longe

14、r, the influence of higher modes of the structure of the earthquake cannot ignore the damage 7, masonry building,Rigid roof is the upper lower light damage, heavy damage. The axial force of column 8, the greater the ductility of the columns is worse. 10, bent structure according to the bottom shear

15、method, single particle system for all gravity load representative valueShort answer1. geological time; the clay content in the soil; relative density of soil; soil depth and the depth of underground water level; earthquake intensity and earthquake magnitude and duration.2. indirect: indirect effect

16、 tremendous acceleration of strong vibration cause the formation of the ground. The complexity of ground vibration is very complicated and not accurate calculation. The random: time, location, size of uncertainty, designed by a reflection spectrum curve, the average is only statistically. The coupli

17、ng of vibration period about earthquake and structure, if the change of vibration period, then the earthquake also changes.3. between them without restricting influence each other, improve the structure of the lateral stiffness is often to reduce the cost of the ductility index structure. Bar stiffn

18、ess to the reasonable arrangement, in order to improve the carrying capacity of the building and strive to make each component to resist lateral force in the system stiffness and ductility match. To play the role of the construction of coordination between, improve its bearing capacity.4. layout str

19、ucture should be simple, symmetrical and regular. From the angle of the seismic, the main is to make the center of mass and stiffness of the structure plane center coincides with or as close as possible. In order to reduce the torsional response of the structure; secondly, the layout to make the pla

20、ne as a cross section are as large as possible torsional stiffness to resist torsion, in fact it is difficult to completely avoid.noun1. building structure seismic design: according to the basic design principles and design thought of the formation of the earthquake disaster and engineering experien

21、ce of checking, the overall layout of buildings and structures and the process details of the structure.The 2. magnitude is reflected in the size and scale of an earthquake in the province level, is a quantitative index. The earthquake intensity is degree of various buildings in an area that suffere

22、d an earthquake effect, is a measure of the consequences after the earthquake caused a scale.The 3. predominant period of ground motion in seismic amplitude spectrum, period corresponding to the maximum amplitude of the frequency components, known as the predominant period of ground motion.4.: the s

23、oil liquefaction of loose sand in the underground water level and the saturated silty soil under earthquake action, a variable density trend among soil particles, but because the pore water could not be drained, the soil particles in suspension. As a liquid, this phenomenon is called soil liquefacti

24、on.5. seismic response spectrum for seeking for earthquake, earthquake acceleration seismic maximum absolute acceleration response of single degree of freedom system and the natural vibration period of the definition of the T response spectrum, referred to as the earthquake response spectrum.Four, q

25、uestion1, what is the magnitude? What is intensity? How to evaluate the magnitude and intensity?The magnitude of the earthquake itself said the size of the grade, with the release of seismic energy scale, according to seismic waves recorded by seismograph to determineThe earthquake intensity is degr

26、ee of the ground and all kinds of buildings in an area suffered an earthquake impact, it is classified according to the consequences caused by the earthquake.The magnitude of the general expression of the Richter scale earthquake intensity is based on the seismic intensity scale, namely when the ear

27、thquake, people feel the destruction of buildings and artifacts, surface division phenomenon.Scope 2, the bottom shear method, calculation of whiplash effect.Applicable scope: height of not more than 40 meters, with shear deformation and the mass and the stiffness of the structure along the height d

28、istribution, and the structure is similar to the single particle system, can be calculated using the bottom shear method. In order to consider the whiplash effect, the regulations: calculated using the bottom shear method, the seismic effect of the top roof roof, parapet, chimney, should be multipli

29、ed by the coefficient 3, the most should not pass down, but is connected with the means of the projecting portion should be included in the.The seismic fortification goal of China seismic code 3, and the two stage seismic design method?The first level: when below the region of seismic fortification

30、intensity earthquake effect, generally not damaged or does not need to repair can continue to useThe second level: when hit by earthquake in the region of seismic fortification intensity, may be damaged by general repair or without repair can continue to use; the third level: when a higher than loca

31、l seismic fortification intensity earthquake effect, serious damage to the two stage design method will not collapse or life-threatening the first stage: the design of engineering structure in the earthquake load and elastic deformation force calculation. The second stage: the design of engineering

32、structures (such as the structure of special importance or lateral ability) under rare earthquake elastic-plastic deformation checking.4, what is the dynamic coefficient, seismic coefficient and horizontal earthquake influence coefficient? What is the relationship between the three?The dynamic coeff

33、icient is the ratio of the seismic coefficient of single particle system the maximum absolute acceleration and maximum acceleration of earthquake ground motion is the ratio of horizontal earthquake influence coefficient of earthquake ground motion acceleration and acceleration of gravity is the hori

34、zontal earthquake influence coefficient of the ratio of the largest single particle system of absolute acceleration response and the acceleration of gravity is the product of seismic coefficient and dynamic coefficient.5, what is the essence of strong column and weak beam, strong shear weak bending?

35、 How to realize the cross section through the seismic checking?(1) to Liang Duan before the end column plastic hinge, in order to control the damage of components, the formation of reasonable damage mechanism (2) to prevent shear beam and column ends of brittle failure, to ensure that the plastic hinge has adequate deformation capacity. In the seismic calculatio