梁的种类及其区别（Types and differences of beams）

梁的种类及其区别（Types and differences of beams） 梁的种类及其区别(Types and differences of beams) First, what is the difference between the coupling beam and the frame beam? Refers to the beam and shear wall are connected with both ends of the beam span ratio is less than 5 (see section 7.1.8 of the specific provisions of the "high regulation"); frame beam and frame column refers to both ends connected with both ends of the beam, or shear wall connected but not less than 5 higher than the cross beam. Both have in common is: on the one hand from the perspective of the conceptual design, in the earthquake when they want to appear first in frame beam or beam plastic hinges instead of frame column or shear wall, the so-called "strong column and weak beam" and "strong wall and weak beam"; on the other hand, from the angle of structure, both must meet the seismic structural requirements, specifically to the longitudinal steel frame beams and beams (including steel beam bottom and top beam) must meet the requirements of seismic anchorage length in the anchor into the mount, corresponding to the same level of seismic frame beams and beam stirrup spacing and diameter of encryption area requirements are the same. The two are not the same, lies in the seismic design, allowing the beam stiffness is greatly reduced, in some cases it can even be allowed to quit the job, but the beam stiffness only allowed to reduce, and not allow it to withdraw from work, so the specification of secondary beam is not resting on the coupling beam however, secondary beams could take on the frame of the. General beam cross height is small (less than 5), with shear transfer, so the specification provides some of the beams and frame beam different in structure, is a requirement of coupling beams is encrypted and frame beam stirrup length can be divided into encryption area and non encrypted area, two is the reinforcement on the beam waist the made clear that "wall horizontal distribution reinforcement should be the waist beams through continuous beam configuration in the range when the beam section height pull; more than 700mm, the two sides of the longitudinal structure of reinforced beam is arranged along the high range (waist band) diameter should not be less than 10mm, the distance should not be greater than 200mm; cross ratio not more than 2.5 of the beam, the longitudinal structure of reinforced beams (on both sides of the waist band) area of the reinforcement ratio should not be less than 0.3%" and will be incorporated into the provisions of a strong, and waist reinforcement in beams as long as the "when the beam web height h W = 450mm, in the two side beams along the height of the longitudinal structure configuration should be reinforced, each side of the vertical reinforcement (not including the upper and lower beam reinforcement and erect steel) 0.1% of the cross-sectional area should not be less than the web section area of bhw, and the distance should be less than 200mm." And not a strong clause. In the process of the construction plan review found in design mistakes: one is the ends and shear wall connected and span ratio is less than 5 of the beam into the frame beam, and the stirrups encryption area and non encrypted area, or the span height ratio is not less than 5 of the beam into two beams in coupling beams; the reinforcement table does not distinguish between the beam height and span and general in the description of a "beam waist band. With the shear wall reinforced", if the beam in beam height is more than 700mm or higher than the cross is not greater than 2.5 and with shear wall reinforcement ratio is less than 0.3% or the horizontal distribution reinforcement the diameter is less than 8mm, easy to violate "high regulation" provisions of article 7.2.26, but this still strong, which should arouse people's attention to design. Two. What is the difference between the frame beam and the secondary beam? Normally， The secondary beam is the beam at both ends of the frame beam. There is no seismic requirement for this kind of beam, so it is different from the frame beam in structure. It is illustrated by the example of national standard atlas "03G101-1": (1) the anchorage length of the reinforcing bar on the support of the secondary beam beam is the tensile anchor length La, while the anchor length of the beam reinforcement of the frame beam is the seismic anchorage length laE. (2) the anchor length of the secondary steel beam under the support is generally 12D, while the anchor length of the beam at the bottom of the frame beam is the seismic anchorage length laE. (3) the stirrups of the secondary beam have no minimum diameter requirements, no encryption area and no encryption area requirements, and only need to meet the calculation requirements. But the frame beam has different requirements for the diameter and spacing of stirrups according to the different seismic grade, not only to meet the calculation requirements, but also to meet the structural requirements. (4) in plane representation, the number of frame beam is KL, and the number of secondary beam is L. In the actual construction drawing, there are two main kinds of mistakes that designers easily make. First, in the flat method of the secondary beam, the stirrups are expressed by the encrypted area and the non encrypted area, such as phi 8#100/200 and so on. The two is when the secondary beam is simply supported beam, the number of negative reinforcement support often do not meet the "provisions of article 10.2.6 of the concrete standard" (article 10.2.6 when the actual beam end by some constraints but by simply supported, should be set in the longitudinal structure of steel, bearing the upper region of the cross section area should not be less than the cross beam in the lower part of the longitudinal reinforcement calculation of the required cross-sectional area should not be less than 1/4, and two). Three, what are the differences between the foundation beam and the secondary beam? The fundamental beam refers to both ends and caps or single column connected beams and secondary beams, the same lies in the fundamental beam is no seismic requirements, the fundamental beam beam roof reinforcement in the anchorage length of the bearings for the tensile anchorage length of La, the fundamental beam stirrup is not encrypted and non encrypted area request. And the difference lies in the fundamental beam beam beam bottom reinforcement tensile anchorage length must also meet La requirements, the fundamental beam width should not be less than 250mm, in addition to the calculation of the fundamental beam in the beam under the external requirement of longitudinal reinforcement diameter should not be less than 12mm and not less than 2 (article 8.5.20 see the "ground rules"), not less than 6 @ 200 with stirrups (see section 3.12.1-9 of the "national technical measures for design of civil construction structure") In the actual construction drawings, design personnel mistakes is the fundamental beam simply apply the framework of Liang Deping said, numbered JKL, the stirrup and non encrypted encryption according to district said, such as 8#100/200. The existing national standard flat fattouh concentration and specific structure of basic beam, if designers want to use PIEM atlas, the fundamental beam number JL is more appropriate, and should indicate the reinforcement structure of JL should be "03G101-1" in the description of secondary beam (non frame beam) with details, and beam bottom reinforcement anchored into the bearing length must satisfy the requirements of tensile anchorage length la. Four. What is the difference between a structural column and an ordinary column? Structural columns are not involved in structural calculations. The general approach is to first wall after concrete columns. The longitudinal reinforcement and stirrup only need to be configured, The minimum reinforcement ratio is not required. The longitudinal reinforcement and stirrup of ordinary column should be configured according to calculation, and not less than the minimum reinforcement ratio.