The construction project starts from the preparatory work for the fixed-point construction of engineering survey and setting out, and ends with the foundation, structure, decoration and completion.
Every construction stage is inseparable from the cooperation and installation of electrical concealed works. Before the project starts, it should be installed for construction.
Electrical equipment and wiring; In the construction of foundation works, electrical grounding devices should be installed, and lines leading out and leading into buildings should be provided.
Road embedded pipeline; In the structural construction stage, all electrical pipelines should be concealed, and in the installation construction stage, pipes should be penetrated.
Installation of wires, electrical equipment and appliances; Before the completion of the project, the device should be debugged. Obviously, electrical safety
Installation is the work that runs through the whole construction process, so every electrical process must be completed in the upper and lower civil processes or.
The construction stage of the process is completed, otherwise it will lead to rework, cost increase and even quality and safety hazards and power loss.
The function of gas itself cannot be completed and accepted.
According to the above, it is not difficult to see that the handover of electrical process and civil process in building construction is necessary and directly related.
Quality, safety, cost, etc. Construction project.
Steel bar installation is a special process or a key process because molten steel generally contains a certain amount of free nitrogen (N), also known as residual nitrogen. If the content is too high, the steel will become brittle at room temperature after plastic deformation.
Because steel bars are often used after bending, plastic deformation has already occurred. If the material becomes brittle, the structure cannot bear the external load (such as earthquake) that causes the plastic deformation of the steel bar again. Therefore, both at home and abroad, bending test is included as an important technical requirement in the steel bar standard.
Definition and difference between special process and key process in engineering: 1. Identification of special process
1. Foundation works include:
(1) Foundation treatment construction;
(2) Pile foundation construction;
(3) Foundation pit construction.
2. The main structure engineering includes
(1) welding of steel (reinforcement) structure and construction of fire-proof and anticorrosive coatings;
(2) mass concrete construction;
(3) Prestressed tensioning construction.
3. Waterproof works include:
(1) coiled material waterproof roof construction;
(2) Construction of coiled material waterproof roof;
(3) Rigid waterproof roof construction;
(4) floor waterproof construction;
(5) Underground waterproof construction. Key processes:
Key process: refers to the process that takes up the longest working time in the construction process.
Detailed process of building electrical installation When civil engineering starts the foundation project, the electrical system should do a good job of grounding wire ring network, and then embed the threading pipe and junction box with civil engineering, and reserve holes such as bridge and incoming wire. After the device is installed, the distribution box can be put in place. When the wall is painted, threading and wiring can be carried out. At the beginning of the decoration, the installation of lamps and lanterns should be coordinated with the decoration. When the power distribution rooms can be locked, they can be installed one by one. Then carry out overall acceptance and delivery.
Special processes and key processes of roads, bridges and tunnels are needed. Dude: I'll give you a complete set of railway construction, including subgrade, bridge and tunnel. I hope I can help you. 3. 1.4.2 Construction technology and method of subgrade filling The embankment is filled, which is the part below the bottom of the embankment bed to above the ground. In this part of the embankment, a and b groups of fillers or improved soil are selected according to the road regulations, and the compaction standard is implemented according to the requirements of meeting the design standards. Before subgrade filling construction, surface treatment and foundation reinforcement should be carried out. In the soil foundation area, the stress state of foundation is analyzed before subgrade filling. Subgrade filling shall be carried out in accordance with the method of "three stages, four sections and eight processes". Before filling, the filling compaction test should be carried out to determine the process parameters that meet the compaction requirements, and then it should be extended to large-scale construction. 3. 1.4.2. 1 see figure 3. 1.4-6 subgrade filling construction process. Unqualified, filling the next layer of preparation stage, construction stage, renovation and acceptance stage.
Fig. 3. 1.4-6 Roadbed Filling Construction Process Flow Chart 3. 1.4.2.2 Filling Roadbed Construction Method (1) Construction Preparation (1) Measuring and lofting, restoring the center line and releasing the sideline; Do a good job in geological investigation and soil testing; Do a good job in subgrade waterproof and drainage measures; Organize personnel and machinery to enter the site; Determine the construction sequence and earthwork allocation scheme. (2) Before clearing the table, the positions of various existing obstacles and facilities within the scope of subgrade shown in the drawings or provided by the supervision engineer must be checked and supplemented on site, and the results should be notified to the supervision engineer for verification. After rechecking the design and releasing the subgrade, the site shall be cleaned according to the actual ground conditions and soil conditions and the construction specifications and design requirements. According to the needs of filling construction, site cleaning should be carried out by stages. In principle, it is a comprehensive desktop cleaning and segmented abandonment. Site cleaning includes removing plant roots such as tree roots and turf within the scope of subgrade, and cleaning 30cm-thick planting soil and unsuitable soil within the scope of subgrade filling, until the foundation soil meets the requirements. The soil that does not meet the requirements of subgrade filling should be excavated and transported to the designated spoil ground. (3) Before embankment filling in the test section, select a section with representative geological conditions and section form (length not less than 200m) as the test section. According to the actual situation of this contract section, the filling test construction is carried out for the filling of fill soil. On-site compaction test shall be conducted until the filler can be effectively used to achieve the specified degree of compaction. Records should be made during the test, including the type of compaction equipment, combination mode, rolling times and speed, working procedure, loose laying thickness of each layer of materials, water content of materials, etc. Thus, the regular curves of model, layer thickness, compaction times and design indexes are found out, and the relationship between K30 value and compaction coefficient Kh, porosity n and EV Ⅱ is found out. Through the construction of the test section, the reasonable compaction process parameters and process flow are determined. After the test results are approved by the supervision engineer, they will be used as the basis for the construction of this kind of packing. During construction, the loose laying thickness of filler should not be greater than 90% of the test value. (2) Construction method (1) Embankment filling shall be carried out in layers, with full section and longitudinal section. In order to ensure the compactness of subgrade, the loose paving thickness must be controlled according to 90% of the thickness of subgrade fill in the test section. The loose paving thickness of each layer is not more than 30cm, and the thickness of each layer after compaction is about 25cm. During construction, a ruler shall be erected at the shoulder position to control the paving thickness. Each layer shall be filled once according to the loose laying thickness, and the unloading distance shall be calculated according to the vehicle volume and loose laying thickness, and the unloading shall be directed by a special person. If the ground has a slope, fill it in layers from the lower part. High-fill embankment should be started first and completed as soon as possible, leaving enough settlement time, but the filling speed must be strictly controlled. When retaining wall is used to support high fill embankment, the back of the wall should be backfilled until the strength of wall mortar or concrete reaches more than 75% of the design strength or meets the design requirements. (2) The subgrade filler must meet the design requirements. When different fillers are used in the same operation area, all kinds of fillers should be filled in layers, and the same filler should be used for the full width of each horizontal layer to avoid uneven settlement on the left and right sides of subgrade. If different fillers are used for filling, the number of layers of different fillers should be reduced as much as possible, and the thickness of each filler should not be less than 50cm. Each layer of filling must meet the design requirements of smoothness and road arch to ensure that there is no water on the subgrade filling surface in rainy days. The road arch is set when the first floor is filled in full section, and the thickness is even when the second floor is filled. (3) In order to ensure that the slope compaction is consistent with the whole section of the embankment, both sides of the slope should be overfilled by 0.4~0.5m, and the slope should be brushed manually with an excavator before the subgrade protection construction. After each layer of subgrade is filled and compacted, the sideline is measured and released, and the lime line is sprinkled to control the filling of the upper layer to ensure the slope rate of subgrade slope. (4) Paving and leveling: The filled road section is leveled with a grader while unloading soil, and the road arch is set on each floor as required. After the first section is leveled by bulldozer, it is leveled by grader. The driving route of the motor grader will travel longitudinally from both sides, and will be leveled to the center of subgrade gradually. At the same time, the pit is filled manually to ensure the compaction quality. ⑤ Sprinkling water or airing: When filling the embankment, the water content of the filler should be detected at any time. For fine-grained soil and clayey sand, before rolling, control the water content of the filler not to exceed 2% of the optimal water content obtained from the filling test in the test section. When the water content is low, add water to the soil field to ensure that the water content of the filler reaches the optimal water content. When the water content exceeds the specified value, the embankment filler shall be turned over by plows and rotary cultivators, and the loose thickness of the filler layer shall be appropriately reduced to reduce the water content of the filler, so that the water content of the filler is always controlled within the allowable water content of the construction to ensure the best compaction effect. Under necessary conditions, quicklime can be used to improve the soil to reduce the water content, thus accelerating the filling speed. ⑥ Rolling According to the layered construction drawing and different packing conditions, choose appropriate rolling machinery, and use heavy vibratory roller for filling and compaction, with exciting force of 30 ~ 60t. The rolling sequence is from two sides to the middle, and the curve segment is first inside and then outside. The transverse seams overlap more than 0.5m or about one third of the wheel width, and the adjacent two sections overlap more than1m.. According to the type of filler, the thickness and density standard of filler and the data obtained in the test section, the compaction times are controlled. Before applying vibration pressure, apply static pressure twice. Generally, the times of vibration compaction are: 6-8 times for subgrade surface, 5-6 times for subgrade bottom and 4-5 times for subgrade body. For the compaction near the slope, firstly, initially compact the shoulder with bulldozer until the shoulder does not slip, and then roll it with roller. The distance between the outer edge of the roller and the sideline of the over-filled subgrade is about 30cm to ensure the safety of the roller. When the roller is not suitable for rolling, a small rammer should be used for compaction. ⑦ Before sampling or test, the test visa tester shall ensure whether the filler meets the requirements, whether the rolling section is compacted evenly and whether the thickness of the filler layer exceeds the specified thickness. Compaction quality inspection of subgrade filler should be carried out by layers, filling by layers and rolling construction. On the basis that the filler quality, filling thickness, horizontal and vertical flatness of filling layer meet the specified standards, the compaction coefficient and foundation coefficient of fine-grained soil are measured by sand filling method and K30 load plate, and the foundation coefficient and porosity of coarse-grained soil and gravel soil are measured by K30 load plate and nuclear densimeter, and the next layer is filled after reaching the specifications and design standards. Today, after the embankment is renovated and filled according to the design elevation, it will be renovated and measured. Restore the center line, set a pile every 20m, measure the horizontal elevation, calculate the trimming height, pour the shoulder side pile, build the road arch, and roll it with a flat roller to make the subgrade surface smooth and free of floating soil, and the transverse drainage slope meets the requirements. For the fine-grained soil slope, according to the shoulder sideline pile, the over-filled part will be brushed off manually according to the design slope rate, and repaired and compacted. After transformation, the edge line at the turning point of the slope is obvious, the straight line is straight, the change point is smooth, the slope is flat without concave and convex, and the compaction density is qualified. The treatment includes the treatment of transverse slope, flatness and gradient of subgrade surface drainage. The subgrade treatment is carried out in strict accordance with the design structure size and meets the requirements of technical standards. After the slope is trimmed, the subgrade sideline piles are released. According to the requirements of design specifications, the widened part will be hung up manually, the overflow part will be brushed off, and the folding point will be trimmed. After trimming, the edge line at the turning point will be obvious, straight and round. 3. 1.4.2.3 Construction method of rock-filled embankment When the stone content in the embankment filler is equal to or greater than 70%, it should be constructed as a rock-filled embankment; When filling embankment with stone, the construction of filling test section should be carried out first, and its compactness should be determined through field test and reported to the supervision engineer for approval. Dumping method shall not be used for construction to prevent the separation of earth and stone, and the filling shall be carried out in layers. When filling in layers, the loose laying thickness should be 400 mm or determined through tests. Ensure that the earth and stone are fully mixed in the filler, and the filler grading is good. Do not meet the requirements, it should be turned manually or mechanically. The stone strength and size of rock-filled embankment meet the specification requirements. In order to ensure that the slope compaction is consistent with the full-face embankment, the construction should be carried out in strict accordance with the position and slope of the slope. After each layer of subgrade is filled and compacted, the sideline is measured and released to control the upper layer of rockfill and ensure the slope rate of the slope. Paving and leveling: after the stone filling section is discharged, it will be leveled with bulldozer. After a section is leveled by bulldozer, it shall be leveled and tightened manually, and the big face of the stone shall be placed smoothly downward, and leveled with small stones. Rolling: According to the layered construction and different packing conditions, select the appropriate rolling machinery, and use impact roller to roll the filling and compaction operation. The rolling sequence is from two sides to the middle, and the curve segment is first inside and then outside. The transverse seams overlap more than 0.5m or about one third of the wheel width, and the adjacent two sections overlap more than1m.. Renovation includes the renovation of drainage cross slope, flatness and slope of subgrade surface. Subgrade renovation is carried out in strict accordance with the design structure size and meets the requirements of technical standards. Roadbed renovation of rock-filled embankment mainly adopts roller combined with manual renovation. 3. 1.4.3 Construction technology and method of cutting excavation. After cutting excavation, it shall be allocated according to the earthwork allocation scheme. The short and shallow cutting in gentle section adopts full-face excavation method without layering; When the height of the cutting center is more than 5m, layered excavation along the slope or longitudinal step method should be adopted. Before cutting excavation, first check the geological data, and at the same time do a good job in waterproof and drainage facilities at the top of cutting. Temporary drainage facilities are combined with permanent drainage facilities and connected with the original drainage system. In the process of cutting excavation, in order to ensure that the rain does not wash the slope, 50cm is reserved on each side, and when the excavation reaches the design elevation or platform position, the slope is brushed once. Brush the slope to ensure the slope and smoothness, and do a good job of slope protection for special parts. Take timely measures to drain the surface water and groundwater that affect the slope stability, and set a drainage slope on the cutting surface to facilitate drainage. Before cutting excavation, check other unstable conditions such as dangerous stones and cracks on the top and slope, and take measures to deal with them properly according to the situation to ensure construction safety. Cutting excavation should be carried out from top to bottom to prevent undercut excavation. (1) After the cutting is excavated to the design elevation, the inner layer of subgrade bed thickness shall be inspected and tested by means of engineering geological mapping, in-situ testing, electrical geophysical prospecting and drilling sampling. According to the test results, for the sections that can't meet the requirements of dynamic stability of subgrade bed, according to the slope of the line, replacement or foundation reinforcement construction is adopted as designed. (2) The hard rock cutting is excavated by loose blasting. According to the lithology, occurrence and excavation height of rocks in the cutting excavation area, detailed blasting design is carried out, and the charge is strictly controlled. After blasting, the slope and top of the cutting mountain are stable, the bed surface and slope are smooth and complete, and the uneven part of the slope is filled with concrete or mortar rubble. DTH drilling rig is used for drilling and loose blasting in blasting construction. During blasting construction, the construction shall be carried out in longitudinal sections, vertical layers and layer by layer. After the crushed graded particle size meets the requirements of group A and B fillers, it will be excavated by loaders and excavators, and transported to the filling area by dump trucks for use. Smooth blasting excavation of slope. When digging to the design elevation of cutting bed surface, shallow hole blasting or cushion charge at the bottom of the hole is used to control the charge of smooth blasting. After the cutting bed is excavated to the bottom of the cutting, the rock shall be identified and inspected, and then the setting-out shall be measured according to the designed section, and the excavation shall be corrected. For the insoluble rock section, the bed surface and below are not changed, and only the uneven part is leveled with C 15 concrete; For soluble rock section, according to the design requirements, dig over 0.2m and replace it with C20 concrete. At the same time, pits, ditches and dissolved cracks are filled with C 15 flaky concrete. , and take measures to rectify the unreplaced karst part below the foundation bed. (3) The construction of expansive soil cutting should try to avoid the rainy season. During construction in rainy season, the slope with retaining structure shall be arranged in time, and the slope shall be built with excavation and closed in time. When it is impossible to build with the excavation, a protective layer with a thickness of not less than 0.5m should be reserved for the slope, and the slope should be brushed in place at one time when building in the future. The replacement and filling of subgrade bed of expansive soil cutting should be carried out immediately after excavation. When it is difficult to connect the front and back processes, temporarily leave a protective layer with a thickness of 0.5m and excavate at the same time. The excavation surface of expansive soil cutting construction should maintain a drainage slope of not less than 4% to prevent water accumulation. For cohesive soil with high viscosity and high water content, it should be properly dried before excavation. (4) Before the construction of deep cutting high slope (the height of excavated slope is more than 30m), the engineering geological data of deep cutting high slope and cutting slope determined in the design documents shall be rechecked in detail, and the earth-rock boundary, engineering grade, weathering thickness and fragmentation degree of rock stratum and engineering characteristics of rock stratum shall be collected. According to the detailed understanding of the engineering geological conditions, quantities and construction period, we will provide an appropriate number of mechanical equipment and labor. The high slope of deep cutting should be constructed in strict accordance with the design slope. If the actual geology of the slope is inconsistent with the geological data of the design exploration, especially if the geology is loose, the opinions on changing the design should be put forward in time and implemented after approval. For deep cutting high slopes with steep slopes in soft rocks such as sandstone, mudstone and shale, according to the ground transverse slope, the toe of the slope is reinforced by cutting retaining wall between piles, anchor piles, pile plate walls and anchor plates, and the first-class anchor (cable) frame beam is sprayed and planted on the top of the pile (wall) every 10m, and a platform with a width of 2 ~ 4m is left. The drainage facilities on the platform should be connected with the drainage system. For the fully weakly weathered hard rock slope, the graded smooth blasting is used for embedding treatment, and the upper weathered slope is protected by retaining the platform and setting a herringbone water-cut skeleton; Low retaining wall (soft rock section) and retaining wall (broken hard rock section) are used at the foot of deep cutting high slope with gentle terrain, and the slope above the wall top is excavated in stages, and the slope surface is protected by herringbone water-cut skeleton (or anchor beam) with sprayed plants, grass and shrubs. Multi-layer transverse full-width excavation method is adopted in the construction of deep cutting high slope on one side slope. The construction of deep cutting high slope on both sides adopts layered longitudinal excavation method and channel longitudinal excavation method. If the longitudinal length of the cutting is large and the thickness and height of the earth wall on one side of the slope are not large, the sectional longitudinal excavation method can be adopted. Construction machinery can use excavators with dump trucks or bulldozer loaders with dump trucks. Deep cutting and high slope excavation must be carried out in stages from top to bottom to prevent undercut excavation. 3. 1.4.4 Construction technology and method of subgrade bed The bottom layer of subgrade bed adopts group A and B fillers or improved soil for mechanized construction. Before construction, the compaction process test should be carried out according to the machinery used and the filler used. According to the method of "three stages, four sections and eight processes", the filling construction is carried out. The first layer should be filled by reverse method. The subgrade bed shall be filled and compacted horizontally in layers according to the full width of the cross section. Bed surface adopts graded macadam until the design elevation. Gravel is transported from gravel yard to graded gravel mixing station along the line. After field test, it is mixed into the best gradation, transported to the site, spread in layers with a paver, and rolled in layers with a heavy roller. The bed surface adopts "four sections and six processes" mechanized construction. Before filling construction, according to the original filler mixture ratio determined by indoor test, select representative road sections for filling and compaction construction technology test to determine compaction construction technology parameters.
How to verify or confirm key processes or special processes? I'm happy to answer your question.
Viewing the operation records of key processes or special processes is verification or confirmation. Must meet the requirements of key processes.
Satisfied adoption!
What are the key processes and special processes for HVAC system installation? For details of pressure test and strength test, please refer to Installation Code of HVAC System and Training Textbook for Advanced Refrigeration Equipment Maintenance Workers. Good luck!
What's the difference between civil building electrical installation and industrial electrical installation? According to the requirements of the buyer and the agreement between the supplier and the demander, other steel pipes other than those specified in the table can be manufactured.
2. At the time of delivery, each steel pipe is attached with a pipe joint. If the theoretical quality of steel pipe is calculated, the quality of pipe joint should be added.
3. Steel pipes are usually 3 ~ 9 meters long.
4. According to different coating types and thicknesses, the theoretical mass of galvanized or other coated steel pipes is heavier than that of uncoated steel pipes 1% ~ 6%.
5. The steel pipe adopts GB/T 8 164 Steel Strip for Welding Steel Pipe.
What does the building electrical installation do? Hehe, peers.
I used to do electrical installation, but a year later, I jumped ship.
Because I studied electricity before, I worked as a product electrician in Suzhou for one year (electrical installation on machines and non-standard machinery in factories), and now I have done a good job in equipment maintenance.
If you are interested in PLC or MCU, you might as well be a device company like me. The salary of PLC or single chip microcomputer is very high. If you understand, it will be more than 4500. Just not proficient in PLC, so I get 4000 salary.
Of course, if you have enough experience, you can design a research institute. I guess you don't want to stay at the construction site.
What are the definitions of special processes and key construction periods in construction projects? Where are the definitions or explanations of special processes and key processes in national specifications? Special process: it is impossible to directly and simply check the quality of the process after the process is completed-that is, it is difficult or uneconomical to verify whether the product is qualified. For example: welding operation, cast-in-place pile foundation, etc.
Key construction period: refers to the construction time required for key lines (lines with zero total time difference and zero free time difference) on the network diagram, which restricts the whole construction period. The operation nodes on critical lines are called "critical nodes"
-The above can be found in the textbook of the construction engineer or the textbook of the supervision engineer. . . . .