I. Structural Design Basis
1. Basic Structural Design Parameters
The safety level of the building structure is Grade II, and the design service life is 50 years. For the seismic category, seismic intensity, basic acceleration, basic wind pressure and snow pressure, ground roughness category, building site category and other parameters should meet the basic requirements of the code or the competent authorities recognized special consulting report, it is not appropriate to raise the standard.
2, constant load
Roof, floor, ground and building partitions of the standard value of the constant load according to the architectural design of the materials required to use the task book, wall thickness and decoration standards. Wall load calculation should pay attention to distinguish between the fire partition wall and ordinary lightweight partition wall capacity.
General parts of the floor practice reference load 2.5kN/m2; ice rink ice area floor practice load 4kN/m2 ~ 5kN/m2; large and medium-sized food and beverage kitchen area 4.0kN/m2, if there is no specific location of the kitchen, you can appropriately expand the reserved kitchen area.
In the design of construction drawings, the corresponding load should be reserved for the facade (curtain wall, light box, LED screen), with special attention to the glass curtain wall and stone curtain wall load should be taken according to the drawings.
3, live load
(1) commercial retail: 4.0kN/m2; the first floor 5.0 kN/m2
(2) cinema 3.5kN/m2; KTV, video games, ice rinks: 4.0kN/m2 (3) fitness centers: 4.0kN/m2 (swimming pools can be considered in accordance with the constant load of the body of water) (4) food and beverage: 4.0kN/m2 for the kitchen, 4.0kN/m2 for the dining room. kN/m2, dining area 4.0kN/m2 (6) bathroom 2.5kN/m2 (7) fire stairs: 3.5kN/m2
(8) supermarket live load reference value: fresh area, grocery area, grain and oil area 10.0kN/m2, warehouse 15.0kN/m2, leased area 4kN/m2, receiving area 15kN/m2, the general area of the store 7.0 kN/m2, loading and unloading area 20K N/m2
(9) live load on the roof: 3.0kN/m2, excluding green mulch and roof large equipment load
4, equipment load
Equipment room load value is appropriate to be provided by the equipment professional calculations in accordance with the actual situation. Otherwise, it can be taken in accordance with the "national civil building structure technical measures". For HVAC equipment placed centrally on the roof, the structural design needs to be provided by the equipment specialty to provide the appropriate information.
5, fire truck load
Should take into account the most unfavorable arrangement of the load and the stress diffusion of the bedding under the wheels, converted to an equivalent uniform load. For the foundation, crack control only consider the usual use of loads, beams, columns, floor strength design to consider the combination of fire truck loads. When the structural plate exists on the soil or other filler, the wheel pressure of the fire engine needs to consider the stress diffusion to be discounted after acting on the structural beams and plates, the fire engine load in accordance with the specification requirements for the most unfavorable arrangement of the beams and plates of the calculation of the cross-section and reinforcement. Columns, foundation design and crack width control does not take into account the fire truck load, but should meet the requirements of the normal use of load.
6, other loads
The main atrium area can appropriately increase the live load for water features, large sculptures and other possibilities reserved. Main atrium top light roof, should be reserved for hanging load. The value of suspended load is based on the recommendation of the extension department. The effect of loads from large diameter water pipes hanging from the basement roof should be considered. Other unlisted loads shall be valued according to the code.
Second, the main materials
Reinforcement bars
Strength control by the force reinforcement (including longitudinal reinforcement and hoop bars), give priority to the use of HRB400-grade reinforcing bars, to be given to the specification of a higher level of reinforcing bars after the higher-strength level of reinforcing bars can be used. Reinforcement controlled by the structure can be compared with the price of steel, the use of lower grade varieties to reduce costs.
Concrete
The underground part, except for vertical components, is recommended not to exceed C35, and the highest concrete grade is recommended not to exceed C60. backwater zone is recommended to be used than the corresponding component parts of the concrete strength grade of concrete of micro-expansion concrete, and the rest of the calculation shall prevail.
Block and partition wall
Partition wall with fire protection function should use lightweight block that meets the specification requirements, and the general partition wall should use lightweight materials that are commonly used in the local area.
Steel, steel plate, steel pipe
Q345B, Q235B
Three, structural program design points
1, program stage preliminary calculations
Program stage should be selected structural form of preliminary calculations. Should have a deep understanding of the detailed structure of the building program and the highlights of the modeling, for the program that may seriously affect the size and arrangement of the structural components, to put forward reasonable suggestions. At the same time, the program design should also be considered to shorten the construction period, reduce construction difficulties.
2, structural form selection
Considering the building height, seismic grade, site conditions and other factors, compare the structural form of frame structure, wall less frame, frame shear wall, etc., and choose the best.
3, the structure of the permanent seam division principles
Basement should not be set up permanent seams, the ground set up structural seams should try to divide in accordance with the division of the industry, the length of the structural unit should not be more than 150 meters after the division of the seams and the structural seams shall not be passed through the cinema hall. In consideration of the structural design of the economy, can take appropriate structural measures to appropriately reduce the setup of structural joints.
4, the choice of column spacing
Column spacing should be selected to ensure that the number of parking spaces in the basement to maximize the general situation of a span of columns should be able to set up exactly three or four parking spaces; for the underground garage occupying the parking space should be careful consideration of the arrangement of columns, it is desirable to take appropriate measures to cancel the columns.
5, frame beam cross-section selection
Frame beam cross-section size should be taken into account the height of the storey and economy and other factors, choose the most reasonable size, such as 6, 7 degrees of 9.0m standard columns in the area of the frame beam cross-section of the network can be considered 300 × 700, in order to reduce the hoop tendons. Secondary beam cross-section is suitable to choose 250×550, which can avoid the setting of constructional waist reinforcement.
6, indoor active line, atrium, connecting bridge structure program
The region overhanging length less than 6 meters of overhanging beams, preferably concrete structure, according to the span-to-height ratio of not less than 5 control. For overhanging beams greater than or equal to 6 meters, it is recommended to use steel concrete members or steel structural members. The span-to-height ratio of continuous concrete beams in this area is controlled at not less than 18, and when ordinary beams cannot meet the design requirements, one-way bonded prestressed concrete beams or profiled steel and concrete beams are preferred.
7, standard floor structure
Slabs with square grid are recommended to use cross beams or parallel primary and secondary beams, and slabs with rectangular grid are preferred to use parallel primary and secondary beams.
8, the basement roof structure
The thickness of the basement roof is generally not less than 180mm, and it is required to make a comprehensive economic comparison between the slab structure and the beam and plate structure, and choose the best one.
9, basement floor structural form
The determination of basement floor structural form should take into account the basement reaction force, foundation depth, pit support, basement backfill and other factors, and select the most reasonable floor structural form. In general, it is recommended to prioritize the use of beam raft and flat plate structure form.
10, sightseeing elevator design
Sightseeing elevator design is recommended to use steel frame structure, beams, columns components can be selected from the rolled rectangular steel pipe or round steel pipe, connecting nodes should be directly butt welding. Sightseeing elevator floor stay position of the main visual surface should not be steel beams blocking the line of sight. Members of the section size should not exceed 200. sightseeing elevator at the overhang is too large, can be set up sightseeing ladder corner columns, in order to control the height of the structure.
Four, structural construction drawing design
1, construction drawing design must be considered to reduce the complexity of construction, shorten the construction cycle.
2, the choice of pile type should be based on the use of the building requirements, the type of superstructure, load size and distribution, engineering geology, construction conditions and the surrounding environment and other factors to consider, choose the best. For the project which has the condition to utilize the post-compression grouting technology, the post-compression grouting method of reinforcing the foundation at the pile end of the drilled piles should be considered as a priority.
3, raft plate and bearing platform in principle should not be set up in the dark beam
Because of the raft plate, pile bearing platform own stiffness is very large, completely by the concrete to provide shear bearing capacity, the dark beam tendons are not involved in the calculation, and the construction of the difficulty, so do not recommend setting up. Double pile bearing platform except.
4, basement wall reinforcement
Commercial complex basement wall is generally longer, considering factors such as crack resistance, it is appropriate to use through-length reinforcement, and reinforcement arrangement should be used in a fine way.
5, retaining wall earth pressure value is recommended to consider the favorable role of pit support
When there are rigid piles or ground wall as pit support structure, considering its favorable role, it is recommended that the design of external wall according to the active earth pressure.
6, the top slab of basement should be given priority as the embedded end of the structure for calculation and analysis.
7, anti-floating calculation should consider the pile weight, it is recommended to fully consider all favorable loads.
8, basement watering zone should be set to consider the possibility of early closure, the construction drawings can be properly considered when design.
9, the structure of super-long treatment recommendations:
1) non-slab structure floor can be considered along the longer direction of the slab reinforcement pull-through;
2) slab structure should be considered as part of the slab reinforcement pull-through to resist the shrinkage and deformation of the concrete;
3) it is not recommended to add fibers to the concrete, expansion agents and apply prestressing and other measures. 10, beam upper span, lower support at the reinforcement should not be all through-length configuration. Suspended beams should be designed with variable cross-section and should not be constructed with horizontal plus axillary . 11, adjust the beam-column eccentricity to avoid adding axillary beam level
Beam-column eccentricity is greater than 1/4 of the width of the column, according to the specification requirements need to be added to the axillary processing, but due to the beam horizontal addition to the axillary construction is more complex, the design should be adjusted to the eccentricity of the distance between the beams, as far as possible to avoid. 12, multiple beams intersecting beam-column nodes should be designed to ensure the construction quality, especially more than four intersecting beam-column nodes, the column head reinforcement is too dense to concrete difficult to vibrate and compact, easy to cause construction difficulties and safety issues. It is recommended to take the following measures:
1) beam as far as possible continuous arrangement or pick out the end of the column double the anchorage length, to avoid the beam reinforcement anchored into the column head;
2) this part of the beam to adjust the amplitude coefficient, can be considered in the range of 0.75 ~ 0.85;
3) beam lower longitudinal steel node processing can be used not all the way into the practice of the support, to reduce the reinforcement within the column Lap;
13, the control section of the frame beam is generally taken at both ends of the column edge and the maximum bending moment in the span, and the control force corresponding to the reinforcement of the beam section at the edge of the column should be taken as the actual combination of the internal force of the section at the edge of the column.
14, in the beam-column node at the embedded parts due to the more dense steel, embedded parts should be considered in the design of construction convenience and reliability.
15, prestressing anchor head sealing anchor should not protrude from the structure of the outer edge line structural beams, columns should be reserved grooves for anchor head sealing anchor, or the anchor head will be extended to the floor sealing anchor, to avoid the impact on the building.
16, to give full play to the bearing capacity of the plate, minimize the secondary beam arrangement
The design should be considered to minimize the secondary beam arrangement, such as the local drop plate can be considered to use the folded plate,
Walls are generally not set under the beam, small hole boundary does not set edge beams, etc..
17, for conventional components, should consider the requirements of the component economic reinforcement rate: plate 0.3% to 0.8%, beam 0.6% to 1.5%.
18, structural vertical members should be based on the axial pressure ratio and lateral stiffness and other factors to change the cross-section and the strength of the concrete, and conditions can increase the number of segments.
19, the structure of the light roof should be prioritized to meet the needs of architectural function and modeling, and it is recommended to adopt the form of steel structure which is easy to construct and has a lighter self-weight.
20, the movie theater bleachers should be used in the form of folding plate . The folding position should be designed according to the beam, and the horizontal floor slab thickness of the seating position is recommended to be 80mm. the frame columns under the grandstand should rise to the floor slab of the grandstand, and the frame beams perpendicular to the secondary beams of the grandstand should be arranged.
21, focus on the generator room, large equipment, elevators, window cleaners, etc. on the structure of the requirements of the embedded parts and reserved holes, especially pay attention to the outside wall and equipment installation holes reserved.
22, such as encountering the need to increase the later part of the mezzanine, such as cable mezzanine, garage mezzanine, substation, etc., should be marked in the drawings of the pre-embedded.
23, the fire blocking area of commercial equipment pipe wells is generally larger, it is recommended to consider specific practices in the construction drawings.
Fifth, the building use function control points
1, the structure of the program must meet the main entrance to the shopping center, the atrium and the theater, ice rink, children's experience city and other forms of large space needs, at the same time, according to the needs of the owners, the interior decoration and changes in the form of business reserved for the corresponding possibilities.
2. The column network should be relatively regular to avoid extremely irregular column network. The main atrium of the shopping center, over the ice rink, the theater screening hall shall not be arranged columns; the main entrance of the shopping center, the lobby of the theater, KTV, children's experience city should not be arranged columns.
3, atrium, lighting area of the glass roof directly below the concrete beams and plates shall not appear; atrium pick-up area shall not be exposed beams.
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