Basic knowledge of construction engineering, absolutely dry goods!

1. What is the plot ratio?

Answer: The floor area ratio is the ratio of the total construction area of ​​the project to the total land area. Generally expressed as a decimal. The higher the floor area ratio, the lower the residents' comfort, and vice versa.

 

2. What is building density?

Answer: The building density is the ratio of the base area of ​​the project to the total land area. Expressed as a percentage. The high building density means that the house is "full" in the land, otherwise it means that the house is sparsely built.

 

3. What is the green space rate (greening rate)?

Answer: The green space ratio is the ratio of the total area of ​​green space to the total land area of ​​the project. Generally expressed as a percentage.

 

4. What is the sunshine interval?

Answer: The sunshine distance is the distance between the two buildings before and after according to the sunshine time requirements. The calculation of the sunshine interval is generally based on the height above the window sill on the ground floor of the house at the south of the noon on the day of the winter solstice, which can be illuminated by the sun.

 

5. What is the difference between a building and a structure?

Answer: All houses or places where people produce, live or other activities are called buildings, such as apartments, factories, schools, etc., and buildings where people do not produce or live are called structures, such as chimneys, water towers, bridges Wait.

 

6. What are the "three major materials" of architecture?

Answer: The "three major materials" of construction refer to steel, cement and timber.

 

7. What are the three components of construction and installation engineering costs?

Answer: The construction and installation engineering cost consists of three parts: labor cost, material cost, and machinery cost.

 

8. What is the unified modular system? What are the basic modulus, expanded modulus, and divided modulus?

(1) The so-called unified modular system is a set of basic rules formulated to achieve standardization of design, to make the dimensions of different buildings and branches uniform and coordinated, to make them universal and interchangeable. Speed ​​up design speed, improve construction efficiency and reduce construction cost.

(2) The basic modulus is the basic unit of dimension used in the coordination of the modulus, and M is used to indicate 1M = 1000mm.

(3) Expanded modulus is a type of derived modulus, and its value is a multiple of the basic modulus. There are six types of expansion modules, which are 3M (3000mm), 6M (6000mm), 12M (12000mm), 15M (15000mm), 30M (30000mm), and 60M (60000mm). Larger dimensions in the building, such as bays, depths, spans, column spacing, etc., should be multiples of a certain expanded modulus.

(4) Partial modulus is another kind of derived modulus, and its value is a multiple of the basic modulus. There are three types of sub-modules: 1 / 10M (100mm), 1 / 5M (200mm), and 1 / 2M (500mm). Smaller dimensions in the building, such as gaps, wall thicknesses, structural nodes, etc., should be multiples of a certain sub-module.

 

9. What are the logo size, structure size, and actual size?

(1) The mark size is used to indicate the distance between the positioning axes (openings, depths) of the building, and the dimensions between the boundaries of the building products, building components, and related equipment locations. The size of the marks shall comply with the requirements of the modular system.

(2) Structural dimensions are the design dimensions of building products and building components. Construction size is smaller or larger than logo size. In general, the structural size plus the reserved gap size or minus the necessary support size is equal to the mark size.

(3) The actual size is the actual size of the building products and building components. The difference between the actual and structural dimensions shall be the allowable building tolerance value.

 

10. What is the positioning axis?

Answer: The positioning axis is a line used to determine the position of the main structure or component of the building and the size of the sign.

 

11. What is horizontal and vertical? What are horizontal and vertical axes?

(1) Horizontal refers to the width direction of the building.

(2) Longitudinal means the length of the building.

(3) The axis set along the width of the building is called the transverse axis. Its numbering method uses Arabic numerals to be written in the circle of the axis from left to right.

(4) The axis set along the length of the building is called the longitudinal axis. Its numbering method uses uppercase letters from top to bottom and is written in the axis circle (where the letters I, O, and Z are not used).

 

12. What is the opening and depth of the house?

Answer: The opening refers to the width of a house and the distance between two transverse axes; the depth refers to the depth of a house and the distance between two longitudinal axes.

 

13. What is the floor height? What is the clear height?

Answer: Floor height refers to the height between floors of the building, and the height from the floor or the floor to the next floor or floor; the headroom refers to the headroom of the room and the height from the floor to the ceiling skin.

 

14. What is the total building height?

Answer: The total building height refers to the total height from the outdoor floor to the top of the cornice.

 

15. What is elevation? What are absolute and relative elevations?

(1) The height difference between a certain part of the building and the determined water reference point is called the elevation of that part.

(2) Absolute elevation is also called altitude. In China, the average sea level of the Yellow Sea near Qingdao is set to the zero point of absolute elevation, and elevations throughout the country are based on this.

(3) The relative elevation is based on the ground of the main room on the first floor of the building as the zero point (+0.00), which indicates the height of the floor from the first floor.

 

16. What is the building area, area used, and utilization rate? What is traffic area and structure area?

(1) Building area refers to the product of the length and width of the outsourced dimensions and then multiplies the number of floors. It consists of area used, traffic area and structure area.

(2) The use area refers to the net area of ​​the main and auxiliary rooms (the net area is the product of the net size obtained by subtracting the wall thickness from the axis size).

(3) The utilization rate is also known as the house availability rate, which refers to the percentage of the occupied area in the building area.

(4) Traffic area refers to the net area of ​​traffic connection facilities such as walkways, stairwells, and elevator rooms.

(5) Structural area refers to the area occupied by walls and columns.

 

17. What is the red line?

Answer: The red line refers to the land area granted to the construction unit by the planning department. Generally, a red pen is used on the drawing to have legal effect.

 

18. How are buildings classified?

Answer: The grades of buildings are divided according to the durability grade (life time) and fire resistance grade (fire life).

(1) According to the endurance level, it is divided into four levels: first level, with a durability of more than 100 years; second level, with a durability of 50 ~ 100 years; third level, with a durability of 25-50 years; fourth level, with a durability of 15 years the following.

(2) According to the classification of fire resistance, it is divided into four levels: from level one to level four, the fire resistance of buildings gradually decreases.

 

19. What is a brick-concrete structure?

A: The vertical load-bearing components of the house are brick walls or brick columns, and the horizontal load-bearing components are reinforced concrete floor slabs and roof slabs. This type of structure is called brick-concrete structure.

 

20. What is the framework structure?

Answer: The frame structure refers to the skeleton consisting of columns, longitudinal beams, transverse beams, floor slabs, etc. as the load-bearing structure, and the wall is the envelope structure.

 

21. What is a shear wall?

A: Shear wall refers to the wall that is added in the frame structure to resist horizontal shear. Because the horizontal shear forces to be resisted by high-rise buildings are mainly caused by earthquakes, shear walls are also called seismic walls.

 

22. What is a shear wall structure?

Answer: Shear wall structure refers to the structure in which vertical load is shared by the frame and the shear wall; horizontal load is supported by the frame by 20% ~ 30%, and the shear wall is supported by 70% ~ 80%. The length of the shear wall is designed according to the standard of 50mm per square meter.

 

23. What is a full-shear wall structure?

A: The full-shear wall structure is a structure that uses the inner wall (or inner and outer wall) of the building as a load-bearing skeleton to bear the vertical and horizontal loads of the building.

 

24. What is the tube structure?

Answer: The cylindrical structure is a comprehensive evolution and development of frame-shear wall structure and full-shear wall structure. The cylinder structure is a space-enclosed cylinder formed by concentrating a shear wall or a dense column frame on the interior and periphery of a house. Its characteristic is that the shear wall is concentrated to obtain a large free dividing space, which is mostly used for office building.

 

25. What is a steel structure?

A: The steel structure is a structure in which the main load-bearing components of the building are made of steel. It has the characteristics of light weight, high strength, good ductility, fast construction and good seismic resistance. Steel structures are mostly used for super high-rise buildings, which are costly.

 

26. Compared with the brick-concrete structure, what are the advantages and disadvantages of the frame structure?

advantage:

(1) Light weight: the weight of brick-concrete structure is 1500 kg / m2; the weight of frame structure such as aerated concrete partition wall, light steel keel partition wall is 400 kg ~ 600 kg / m2, only It is 1/3 of the brick-concrete structure.

(2) Flexible room layout: The load-bearing structure of the frame structure is the frame itself, and the wall panels only serve as the envelope and partition, so the layout is more flexible.

(3) Increased effective area: The wall of the frame structure is thinner than the brick-concrete structure, which relatively increases the area of ​​the house.

Disadvantages:

(1) The amount of steel used is about 30% higher than that of the brick-concrete structure, and the cost is higher than that of the brick-concrete structure.

(2) The cross-sectional dimensions of some columns are too large, they will protrude from the wall and affect the appearance.

 

27. What is the difference between foundation and foundation?

(1) The foundation is the soil layer below the foundation, and its role is to bear all the loads from the foundation.

(2) The foundation is a load-bearing component of the building buried below the ground, which is an important part of the building. Its role is to bear all the loads transmitted from the building and transmit these loads, along with its own weight, to the soil layer below.

 

28. What is the foundation depth? What are deep foundations and shallow foundations?

(1) The buried depth of the foundation refers to the vertical distance from the outdoor design floor to the bottom of the foundation.

(2) Foundations with a burial depth greater than or equal to 5 meters are called deep foundations; foundations with a burial depth between 0.5 and 5 meters are called shallow foundations. The buried depth of the foundation must not be shallower than 0.5 meters.

 

29. In what three different ways can the foundation of a building be classified?

(1) According to the materials used: it can be divided into brick foundation, rough stone foundation, concrete foundation, reinforced concrete foundation and so on.

(2) According to structural form: it can be divided into independent foundation, strip foundation, well foundation, plate foundation, raft foundation, box foundation, pile foundation and so on.

(3) According to the stress characteristics of the materials used: it can be divided into rigid foundation and flexible foundation.

 

30. What is a moisture barrier?

Answer: In order to prevent underground moisture from rising along the wall and surface water from eroding the wall surface, waterproof materials are used to separate the lower wall from the upper wall. This blocking layer is the moisture-proof layer. The location of the moisture-proof layer is generally 60mm ~ 70mm under the indoor floor (+0.00) on the first floor, and the elevation is -0.06m ~ -0.07m.

 

31. What is strangling? What is kicking? What are their roles?

(1) The part of the lower part of the outer wall near the outdoor floor is called leg. The role of legging is to prevent the erosion of ground water and rainwater dripping from the eaves, thereby protecting the wall surface, ensuring indoor drying, and improving the durability of the building. The height of the leg is generally the height difference between the indoor floor and the outdoor floor.

(2) The kick is the structure where the inside of the exterior wall and the sides of the interior wall meet the interior floor. The role of the kick is to prevent the wall surface from being polluted when sweeping the floor. The height of the kick is generally 120mm ~ 150mm.

 

32. What is loose water? What is an open ditch? what is the function?

Answer: The scattered water is the drainage slope near the lower part of the foot; the open ditch is the drainage ditch set near the lower part of the foot.

Their role is to quickly remove rainwater dripping from the eaves and prevent the building from sinking due to the accumulated water seeping into the foundation.

 

33. What is chiseling?

Answer: It is to cut out the dents of the finished concrete structure surface.

Role: Make the construction surfaces of the two construction phases adhere firmly. Usually in the cast-in-situ structure, after the cast-in-place slab is poured, the hair must be chiseled to carry out the pouring of the next column wall. Let the concrete bond firmly.

 

34. What is pulling hair?

Answer: After brushing the cement mortar on the wall, use a tool like a brush to pull the cement mortar into a shape that looks like a sharp tip of ice cream.The purpose is not to make the wall too smooth and to produce an orderly reflection of sound and light. For public areas.

 

35. What is shaving?

Answer: Shaving, also known as spraying, uses a special spray gun to spray the cement mortar with small sand with adhesive on the structural level, so that the stucco layer and the structural layer are firmly bonded, and no emptying of the stucco layer will occur.

 

36. What is a stirrup?

Answer: It is used to meet the shear strength of the oblique section. The tensioned main steel bars and the concrete in the compression zone are connected in parallel to make them work together. In addition, it is used to fix the position of the main steel bars so that the various steel bars in the beam form the reinforcing steel skeleton.

The stirrups are divided into rebar, round steel, and cold-drawn low-carbon steel stirrups according to materials.

According to the shape, there are flat stirrups (four sides, eight sides, six sides, ring) and spiral stirrups.

According to the force, there are shear stirrups, restraint stirrups, and distributed stirrups.

According to the composition, there are single support hoop, double support hoop, and multiple support hoop.

 

37. What is the water stop?

Answer: The water stop is generally used for waterproofing of underground engineering. The water stop is divided into: water stop and water-swellable rubber.

First, the water stop belt uses the high elasticity and compression deformation of rubber to produce elastic deformation under various loads, thereby acting as a tight seal, effectively preventing leakage and water seepage of building components, and acting as a shock absorbing buffer. In many engineering buildings, there are certain expansion and contraction requirements between civil and water-soil structures, as well as problems such as waterproof and shockproof. Therefore, the use and installation of rubber waterstops is an effective solution to the above problems. It is mainly used in permanent deformation joints that must be provided when concrete is cast in place, such as canals, tunnel exits, dams, and aqueducts. E-type waterstop.

2. Water-swellable rubber is a new product recently developed. This product is a kind of hydrophilic swellable macromolecule substance added to rubber, which not only has the performance of general rubber products, but also has the unique performance of self-swelling when exposed to water. It is a new type of waterproof material that can stop water. The effect of water is more reliable than ordinary rubber. This product is synthesized from a variety of polymer chemical materials, and its strength is higher than that of ordinary putty, which is especially suitable for waterproofing engineering.

 

38. What is cold processing?

Answer: It usually refers to the metal cutting process, that is, cutting the excess metal layer from the metal material (blank) or the workpiece with a cutting tool, so that the workpiece can obtain a processing method with a certain shape, dimensional accuracy and surface roughness. Such as turning, drilling, milling, planing, grinding, broaching, etc.

In metal technology, corresponding to hot working, cold working refers to the processing technology that plastically deforms the metal below the recrystallization temperature, such as cold rolling, cold drawing, cold forging, stamping, cold extrusion, etc. Cold working deformation resistance is large, while forming metal, work hardening can be used to improve the hardness and strength of the workpiece. Cold working is suitable for processing metal parts with small cross-section dimensions, high processing dimensions and surface roughness requirements.

 

39. What is a daughter wall?

Answer: It refers to the low wall of the house that is higher than the roof.

 

40. What is bidding for construction projects?

Answer: Construction project bidding: refers to a type of construction unit (owner) that issues a notice on the proposed project, and uses contractual methods to attract contractors of construction projects to participate in the competition, and then selects the superior ones to complete the construction tasks through legal procedures. Legal act.

Construction project bidding: refers to the legal act of a construction project contracting unit that has obtained qualifications for bidding after specific review, and submits a bid to the bidding unit within the prescribed time in accordance with the requirements of the bidding documents.

 

41. What is a horizontal wall? What is a vertical wall?

(1) A transverse wall is a wall arranged along the width of a building.

(2) The vertical wall is being built