What Is a Frame Clamp?

Frame structure is a structure composed of many beams and columns to bear the entire load of the house. For high-rise civil buildings and multi-story industrial plants, the bearing capacity of brick walls can no longer meet the requirements of larger loads, and frames are often used as bearing structures. House loads include the weight of people, furniture, items, machinery and equipment, as well as the weight of the floor, walls and itself. The wall built in the frame only serves as the enclosure and separation function. It does not bear other loads besides bearing its own weight. In order to reduce the frame load, lightweight walls should be used as much as possible, such as using foam concrete blocks (wall panels) or hollow bricks. Generally, most of the frames are cast on site. In order to speed up the progress of the project and save formwork and top braces, partial prefabrication (such as columns), partial cast-in-place (beam), or precast joints of column-beam precast joints can also be adopted. ^[1]

Frame structure refers to beams and columns connected by steel bars to form a load-bearing structure

The main advantages of frame building: flexible space separation, light weight, saving material; it has the advantage of being able to flexibly cooperate with the layout of the building, which is helpful for arranging

frame

Difference between frame structure and brick-concrete structure

The difference between frame structure and brick-concrete structure is mainly the load-bearing method. The load-bearing structures of frame-structure houses are beams, slabs, and columns, while the load-bearing structures of brick-concrete houses are floor slabs and walls. In terms of firmness, theoretically speaking, the frame structure can achieve a firmness greater than that of a brick-concrete structure. Therefore, when a brick-concrete structure is used for architectural design, the height cannot exceed 6 floors, and the frame structure can achieve dozens of floors.

However, in the actual construction process, the state has stipulated that the earthquake resistance level of the building must be reached, whether it is brick-concrete or frame, this level must be reached, and the developer will not use the frame structure to build the house. Increase investment, as long as it meets the seismic level.

In terms of sound insulation effect, the sound insulation effect of brick-concrete residences is medium. The sound insulation effect of frame structures depends on the selection of partition materials. Some advanced insulation materials have better sound insulation effects than brick concrete, while ordinary insulation materials such as cement. Hollow slabs and the like have very poor sound insulation.

If you want to transform the interior space, because most of the walls of the frame structure are not load-bearing, the transformation is relatively simple. It is sufficient to knock off the walls, and many walls in the brick-concrete structure are load-bearing structures that are not allowed to be removed. You Can only work on a few non-load-bearing walls. A simple way to distinguish between a load-bearing wall and a non-load-bearing wall is to look at the wall thickness. 240mm thick walls are load-bearing, and 120mm or thinner walls are non-load-bearing. ^[2]

Frame shear wall structure is commonly known as frame-shear structure . It is a combination of frame structure and shear wall structure. In addition to arranging the frame on the structural plane, part of the shear wall (also known as seismic wall) is absorbed. Their respective strengths can not only provide a large use space for the building layout, but also have good lateral force resistance. Shear walls in frame-shear structures can be set individually or can be used

The frame structure can be designed as a statically-determined three-hinged frame or an ultra-statically-determined double-hinged frame and a hingeless frame.

Beam section size

The following requirements should be met:

(1) The cross-section width should not be less than 200mm;

(2) Section

Finite element analysis of algor frame structure

It is mainly based on design basis, earthquake resistance level, civil air defense level, foundation condition and bearing capacity, moisture and impermeability practices, live load value, material level, precautions during construction, selection of detailed drawings, general details or nodes, and construction drawings. Information not shown but expressed through description. For example, the alkali content of concrete should not exceed 3kg / m3 and so on.

Including: (1) the layout of prefabricated panels (selection of panels, dimensions of joints and reinforcement). When labeling the number and type of prefabricated panels, do not use diagonal lines. Because this method is easy to cause the line to cross, the horizontal or vertical line method should be adopted. The same type of room is directly marked with the room type number. It should be uniformly numbered throughout the building, which can reduce the design workload and facilitate the construction staff to see the drawings. The board seam should be 40 as much as possible. When laying the board, use a wide board as far as possible from the inside of the room. The cast-in-situ strip should be left by the window. If the structure requires a complete cast layer, the plate gap should be greater than 60. The thickness of the whole pouring layer is 50, with bidirectional 6 @ 250, concrete C20. Pure frame structure generally does not need to add a whole cast. No prefabricated board shall be laid at the construction column. Underground garages are not available with prefabricated panels due to fire protection requirements. It is not suitable to use long plates for the frame structure, otherwise cracks may easily occur at the parallel connection between the long plates and the frame beams. It is recommended to use PMCAD's artificial layout function to lay out prefabricated panels. Automatic layout may not meet the user's construction drawing requirements, and only meet the requirements for defining load transfer routes. When the floor height is very sensitive, the span exceeds 6.9 meters or does not meet the modulus, SP board can be used, SP board 120 thickness can achieve 7.2 meters span.

(2) Reinforcement of cast-in-place plates (reinforcement of upper and lower plates, plate thickness dimensions). Board thickness is generally 120, 140, 160, 180 four sizes or 120, 150, 180 three sizes. Try to use secondary steel, including secondary steel with diameter 10 (less supply), and reinforced steel bars with diameter 12. Except for hooks, primary steel must not be used. Rebars should have large diameter and large spacing, but the spacing should not be greater than 200, and the spacing should be as large as 200. (Generally speaking, cracks in slabs with a span less than 6.6 meters can meet the requirements). The steel bar on the upper part of the span less than 2 meters does not have to be broken, and the steel bar does not need to be drawn. It only indicates that the steel bar is a two-way double-row 8 @ 200. The space between the upper and lower steel bars should be equal and the diameters can be different, but the type of steel bar diameter should not be too much. On the top layer and when the crack resistance is considered, the ribs can be continuous, or 50% connected. Reinforcing bars are added at the larger places, and the pull-through ribs should be overlapped by the tension. When the plate reinforcement is the same, only the plate number can be marked. Generally, the plate with the same lower rib and part with the same upper rib as a plate number can be used to draw different upper ribs on the drawing. When the shape of the plate is different but the reinforcement is the same, it can be programmed into a plate number. Should be uniformly numbered throughout the building. When considering wearing electrical conduits, the plate thickness is 120, and the practice of thin plates and cushioning is not used. For the plate of the electric tube well wire lead, the thickness of the plate may be increased to 180 due to too many wires (considering the superposition of four layers of 32 steel pipes). It is better to use long span boards as far as possible, not to add secondary beams in the room (especially residential). It shows that the distribution rib is 6 @ 250, and the place where the temperature influence is large can be 8 @ 200. When the elevation of the top of the board is different, the ribs of the board should pass through separately or at an angle. The caster plate's male corners are supplemented with radial ribs (including the male corners on the inner wall). It is advisable to add oblique ribs under the caster to cast the caster. The top floor should recommend Party A to use cast-in-situ floor slabs to facilitate waterproofing, and to strengthen the integrity of the structure and the stability of the decorative edge. The exposed edge, rain cover, and corridor should be provided with 10mm seams every 10 to 15 meters, and the steel bars should be continuous. Wherever possible, use cast-in-place plates instead of pre-made plates and complete pouring. Toilet practices can be 70 thick and 10 height difference (cancel cushion). Non-prestressed boards can be used for boards below 8 meters. The slabs near the corners of the L, T or cross-shaped building planes shall be cast-in-situ and thickened, with two-way double-row reinforcement, and four 16-strength reinforcements at 45 degrees. It is recommended that the reinforcement of cast-in-place plates be automatically generated using PMCAD software. One can speed up the speed, and the other can minimize clerical errors. It is recommended not to number the steel bars when automatically generating floor reinforcements, as hundreds of steel bars may be coded when the project is large, which is difficult to find. If you want to number, the number should not be out of the room. In the calculation of the reinforcement, the plastic internal force redistribution can be considered. The plate reinforcement is multiplied by a reduction factor of 0.8 to 0.9, and the plate reinforcement is multiplied by an amplification factor of 1.1 to 1.2. It is worth noting that the two-way plate reinforcement calculated by elasticity is the maximum value at some places of the plate. According to this, the reinforcement is conservative, and there is no need to manually enlarge it. The negative rib of the plate supported on the frame beam of the outer ring should not be too large, otherwise it will cause excessive additional torque to the beam. Generally: 10 @ 200 is used when the thickness is> 150; otherwise, 8 @ 200 is used.

The following points should be noticed in the plate reinforcement diagram generated by PMCAD: 1. Unidirectional plates are calculated according to plasticity, while bidirectional plates are calculated according to elasticity. It should be changed to a calculation method. 2. When the thick plate and the thin plate are connected, the thin plate support is considered appropriate according to the fixed end, but the thick plate is not suitable. It is appropriate to reduce the reinforcement of the thick plate support and increase the mid-span reinforcement. 3. The non-rectangular plate should reduce the reinforcement of the support and increase the reinforcement of the mid-span. 4. There are too many sides of the room or the concave plate should be checked for its reinforcement with the finite element program. Slabs can generally be calculated in terms of plasticity, especially the foundation floor and civil air defense structures. However, buildings with self-waterproof structure, no cracks and strict requirements for waterproofing, such as slopes, flat roofs, closets, power distribution rooms, etc., should adopt elastic calculation. Generally, the steel bars should not be thickened under the indoor light partition wall. One is that the light partition wall may be displaced, and the other is the overall stress of the board. The reinforcement of the board should be improved as a whole. Only the partition walls that cannot be displaced on the long side of the vertical unidirectional board, such as the partition walls of the toilet and other rooms, can be thickened. Sloped roof slabs are partial tension members and should be reinforced in both directions.

(3) About lintel arrangement and light partition wall. Frame-filled walls are generally light walls, and precast concrete girders are generally not used for lintels, but cast-in-place beams. The light wall practices and atlases used should be indicated, such as Beijing 94SJ19 in the Beijing area, and the reinforcing ribs of the lintel should be indicated. When the lintel is connected to the column or the structural column, the column should be slinged and the lintel is cast in place. It is not recommended to use aerated concrete as the retaining wall. It is difficult to make decoration and cannot be used in toilets.

(4) Details of the arrangement of the awning, balcony, and canopy and its section. Note: The vertical thickness of the canopy and the vertical plate of the balcony should be 80, otherwise it will be difficult to construct. The vertical bars should be placed in the middle of the board. When doing double row ribs, the height is less than 900 and the minimum thickness is 100; when the height is more than 900, the minimum thickness is 120. The vertical boards of the balcony should be casted as far as possible, and the intersection of the prefabricated baffles is easy to crack. When there is a slanted decorative board on the awning and balcony, the steel bars of the board are placed on the top of the slant board and anchored into the wall beam (that is, the double-layered bar of the board) through the lower part of the horizontal board. The sealing plates on both sides can be closed with Taber plates, and the steel wires of the steel bars and Taber plates are welded without using concrete structures. When the length of the picking plate is more than 2 meters, it is better to configure the ribs under the board, and the longer exposed picks (including the vertical board) should be equipped with temperature ribs. The length of the ribs on the inner span of the pallet should be greater than or equal to the length of the outboard of the pallet, especially when there is a concentrated load at the end of the pallet. A small vertical edge should be added to the end of the inner tray to prevent dust from falling during cleaning. When the rain riser on the top balcony is unorganized drainage, the rain riser length should be greater than the length of the lower balcony riser 100. Rain showers must be provided on the top balcony. There should be room for the reinforcement of the picking plate, and large diameter and large space reinforcing bars should be used to give workers a place to prevent their feet from bending. The span of the inner span of the pallet is small, and a negative bending distance may occur in the span. The negative rib of the pallet support should be extended across the full span. The ribs on the end of the pallet are usually rounded upwards, but it is difficult to construct when the diameter of the steel bar is greater than or equal to 12, and additional ribs should be added.

(5) Stair layout. X-shaped diagonal lines are used to indicate the stairwells, and it is noted that the stairwells are detailed separately. Use staircases as much as possible, which is convenient for design and construction and is more beautiful.

(6) Elevation at the top of the board. Can be described under the name of the majority of the plate thickness and the top of the plate, kitchen and toilet and other special places in their rooms are additionally marked.

(7) The beam layout and its number should be numbered according to the floor, such as L-1-XX, where 1 refers to 1 floor, and XX is the number of the beam. Column arrangement and numbering.

(8) The size of the opening of the hole on the board (kitchen, toilet, electrical and equipment) and its additional ribs. The additional ribs do not necessarily have to be anchored into the board support, and can be anchored into the La from the edge of the hole. For the additional ribs on the board, if the board has only a positive bending distance at the opening, it can be reinforced only under the board; otherwise, additional ribs should be added on the board. Reinforced slabs should be indicated by dashed lines with a dashed line, and it should be noted that the slabs should be poured with a level of expanded concrete. Effective support measures should be taken before pouring. The large hole in the residential staircase staircase has a large hole in the floor, and it is not suitable to add beams around it. The finite element program should be used to calculate the internal force and reinforcement of the plate. The board is appropriately thickened, and the beams are darkened at the edges.

(9) Location and detailed drawings of manholes and ventilation holes on the roof.

(10) The details that cannot be clearly expressed in the plan should be added to the section. Based on the section of the building wall, a detailed structural drawing can be correspondingly drawn.

Basic floor plans and details

(1) When the width of the expanded foundation under the column is wider (greater than 4 meters) or the foundation is uneven and the foundation is soft, the strip foundation under the column should be used. The unfavorable factors of bidirectional repeated use of the foundation bottom area at the nodes should be considered, and the foundation should be appropriately widened.

(2) When there is an air-raid shelter or a dry well under the foundation, a large thick plate can be made to cross it.

(3) A cushion layer should be used under the concrete foundation. When there is a waterproof layer, the thickness of the waterproof layer should be considered.

(4) The construction site is better. When the foundation burial depth is greater than 3 meters, Party A should be recommended to be a basement. When the bearing capacity of the basement floor of the basement meets the design requirements, it can no longer be extended to facilitate waterproofing. A post-casting belt is set every 30 to 40 meters, and it is indicated that it will be poured with slightly expanded concrete after two months. The basement can reduce the additional stress of the foundation, increase the bearing capacity of the foundation (especially useful when there are buildings around it), and reduce the impact of the earthquake on the superstructure. There should be no partial basement, and the basement should have the same burial depth. The polystyrene board can be hollowed out in the middle of the raft zone to adjust the uneven settlement of the upper and lower layers.

(5) When the underground outdoor wall is concrete, the corresponding floor beams and foundation beams can be cancelled.

(6) Seismic joints and expansion joints may be provided below the ground, and joints shall be strengthened. However, the wall foundations on both sides of the settlement joint must be separated.

(7) The foundation of the new building should not be deeper than the surrounding foundation. If it is deeper than the original foundation, the net distance between the foundations should be no less than 1.5 to 2 times the height difference between the foundations, otherwise anti-slip piles should be driven to prevent damage to the original building. When there is a large difference in the number of building layers, coke should be placed in the area of the center of the base grid with a lower number of layers to adjust the additional stress of the foundation.

(8) The eccentricity of the independent foundation cannot be too large, and if necessary, it can be made into a column base with a similar column. The eccentricity of the bottom plate of the strip foundation under the column cannot be too large, and if necessary, it can be made into a free plate on three sides supporting one side (similar to the middle opening of a raft foundation). The load center of gravity of the base of the two columns and the centroid of the foundation slab should coincide. The foundation slab can be made trapezoidal or stepped, or the length of the cantilever at both ends of the cantilever can be adjusted.

(9) When an independent column foundation is used, the bending reinforcement of the independent foundation need not meet the minimum reinforcement ratio requirement. Unless this foundation is very important, the reinforcement must not be too small. The independent foundation is a structure between reinforced concrete and plain concrete. Conical foundations should be used for small-sized independent foundations to facilitate construction.

(10) The tensioned beam of the independent foundation should be long reinforced, and the bottom of it should be coke. The elevation of the top of the beam should be higher, otherwise the bottom wall is too high.

(11) The bottom partition wall is generally not used as a foundation, and the concrete cushion on the ground can be partially thickened.

(12) Considering that the general building settlement is the shape of a pot bottom, the overall bending of the structure and the synergy between the upper structure and the foundation, the top and bottom steel bars should be pulled through (multi-layered negative bars can be cut off by 1/2 or 1/3), And the bottom reinforcement of the longitudinal foundation beam should also be pulled through.

(13) A north arrow should be added to the basic plan.

(14) The base floor concrete should not be larger than C30. One is useless, and the other is prone to cracks.

(15) JCCAD software can be used to automatically generate the basic layout and detailed drawings. The generated base plan is named JCPM.T.

(16) The bottom area of the foundation should not be excessively increased due to the additional force of the earthquake, otherwise it will be safe under an earthquake and the settlement will be different under normal circumstances, and the bottom will be inverted. ^[4]