Is the frame structure really earthquake resistant, and the beam in the frame structure is earthquak

"Zhuxun China"Finishing:

First of all, the seismic system of frame structure is generally only suitable for multi-storey buildings, and pure frames cannot be used above high-rise buildings, whether for civil or industrial purposes. If you question that frame structures are not earthquake-resistant, then designers are not going to make frame structures ubiquitous in multi-storey buildings.

In fact, any structural system can be seismic resistant (within the height range of which the structural system itself is applicable), depending on how high the seismic rating the designer gives it, and that's it. It's just that the lateral stiffness of the pure frame is relatively small, so it is estimated that the earthquake cannot be carried by the earthquake. Of course, whether the final product can withstand earthquakes depends on whether the conscience value of the construction unit meets the needs of the public's safe survival.

Secondly, the matter of falling off the wall skin is a common problem in concrete. Due to the ubiquity of concrete cracks, they cannot be avoided at present, so they can lead to a series of damage. This is not avoided because it is a frame structure or a frame-seismic wall structure or a seismic wall structure.

What's more, there are many factors that lead to concrete cracking, not to mention the shrinkage of the concrete itself, but also has a lot to do with the environment in which the concrete exists, relative humidity, temperature, etc., and is also related to the cement varieties used by the construction unit, aggregate varieties, admixtures, and maintenance. None of this really has anything to do with the fact that it's a frame structure.

The seismic performance of the frame structure is not very good.

What are the seismic structures of beams in frame structures?

1) Beam cross-sectional size: In order to prevent the beam from oblique crack failure and oblique brittle failure, the cross-sectional size of the frame beam must meet the following requirements: the ratio of the cross-sectional width to the height of the beam is b h, and b should not be less than 200mm, nor less than 1 2 column width; At the same time, the high span ratio ln h 4 should be satisfiedThe maximum average shear stress of the beam is v bh0 wherein b, h, h0 are the cross-sectional width, height and effective height of the residual wax beam, respectively. v is the design value of the combined shear force at the beam end; FC is the axial compressive strength of the concrete.

2) Reinforcement ratio of beam: In order to ensure the deformation capacity of the beam and make the frame structure have good seismic performance, the reinforcement ratio of the longitudinal tensile reinforcement at the beam end should be able to make the relative height of the compression zone of the beam end section meet the following requirements: first-level frame x; At the same time, the reinforcement ratio of the longitudinal tensile reinforcement should not be greater than.

3) Stirrups of the beam: In order to ensure that the beam has sufficient ductility, improve the ultimate compressive strain value of the concrete in the pressure zone of the plastic hinge area, and prevent the final oblique crack failure in the plastic hinge area, the encrypting closed stirrups in the yield range of the longitudinal reinforcement at the end of the beam is very effective in improving the deformation capacity of the beam. At the same time, in order to prevent premature compression of the crimping bars, the spacing of the stirrups should be strictly limited in accordance with the "Seismic Code".

4) Longitudinal reinforcement anchorage in the beam: under the action of repeated dead load, within the considerable length range of the longitudinal reinforcement embedded in the beam-column node, the adhesion between the concrete and the reinforcement will be seriously damaged, so it should be noted that the anchorage length of the longitudinal reinforcement in the frame beam under the action of the frame beam should generally be larger than the basic anchorage length of the tensile reinforcement specified in the "Structural Code".

1. Classification Standard for Seismic Fortification of Construction Projects (GB50223-2008);

2. Code for Seismic Design of Buildings (GB50011-2010). First, the classification of seismic fortification of buildings is determined according to the "Classification Standard for Seismic Fortification of Construction Projects", and then the seismic grade of the building is determined according to the "Code for Seismic Design of Buildings" (page 49).

Yes. Residential buildings are classified as Class C fortifications, and the six-storey frame structure will not exceed 24 meters high, which is classified as Class IV seismic resistance. See GB50011-2010 "Code for Seismic Design of Buildings" table.

It's not necessary, it's enough to meet the construction measures at 6 degrees.

The seismic rating is required on the drawings. The design description can be found on the description.