3 project construction plan

# Planning # The introduction plan should make specific and clear arrangements for the work content, target requirements, implementation methods and steps, leadership guarantee, supervision and inspection of a certain job. The following is the construction scheme of finishing project, welcome to read!

1. Project construction scheme

I. Project Overview This project can be divided into: water supply and drainage engineering, heating engineering and ventilation and air conditioning engineering.

Second, the construction technology

1, pipeline installation

Project content: pipeline pay-off, support and hanger installation, main pipeline, riser installation, branch pipe installation, valve installation, accessories installation, anti-corrosion and heat preservation.

Pipeline avoidance: water supply and heating pipelines should make way for drainage pipes, water supply pipelines should make way for heating pipelines, small-diameter pipelines should make way for large-diameter pipelines, and pressurized pipelines should make way for non-pressure pipelines. All processes must be reasonably configured, and the pipeline direction and support position of this project must be determined and adjusted.

(1) pipeline threaded connection

1) The water supply pipeline is connected with threads.

2) Draw a line on the pipeline according to the sketch of field surveying and mapping, and break the pipeline according to the line.

3) Electric threading machine shall be adopted, and the DN above DN25mm shall be carried out twice. When crossing a long pipe, the rear end of the pipe should be horizontal.

4) Pipeline threaded connection should be filled with appropriate fillers between internal and external threads, generally using white thick paint for oiling hemp, or using raw adhesive tape.

5) When installing threaded parts, they should be installed at one time according to the tightening direction, and cannot be installed backwards. After installation, expose 2~3 threads and remove the remaining filler.

(2) Pipeline welding

1) When welding pipes, remove rust, dirt and grease from pipe joints.

2) When cutting steel pipe, the cutting surface should be perpendicular to the center line of the pipe to ensure the concentricity of the welded pipe.

3) When the wall thickness is above 5mm, groove cutting shall be carried out to ensure complete penetration. The groove can be formed by gas welding cutting or beveling machine, but the slag and iron oxide should be removed and polished with a file until the metallic luster is exposed.

4) When welding pipes, center the axes of the two pipes and fix the ends of the two pipes by spot welding.

5) When the pipeline is welded to the flange, the pipeline should be inserted into the flange first, then aligned with a square after spot welding, and then welded after leveling. Flange should be welded on both sides, and the welding on the inner side should not protrude the sealing surface of flange.

6) Flanges shall be perpendicular to the center line of the pipeline and their surfaces shall be parallel to each other. Flange gaskets should not extend into the pipeline. The bolt specification of the connecting flange should match the flange, and the length of the screw protruding from the nut should not be greater than 1/2 of the screw diameter.

7) Flange gaskets shall be selected according to the requirements of drawings and specifications. Rubber pad is used for cold water system and asbestos rubber pad is used for hot water system.

(3) drainage PVC pipe

1) Select qualified pipes and fittings according to the measured sample drawing, and prefabricate the pipe section. After the fabrication of prefabricated pipe sections is completed, check the dimensions between nodes according to the sample drawings.

2) When the PVC pipe is connected with the cast iron pipe, the PVC pipe should be bonded with the cast iron pipe after grinding.

3) transport the materials and prefabricated pipe sections to the installation site, and install the pipes, pipe fittings and expansion joints in turn according to the reserved nozzle position and pipeline centerline, and connect the nozzles.

4) The setting of expansion joint on the horizontal main pipe shall be determined according to the calculated expansion amount. When the confluence fittings on the horizontal branch pipe reach the riser for more than 2m, expansion joints shall be set, and the distance between expansion joints shall not exceed 4m. When the pipe end extends into the expansion joint, the reserved clearance is 5- 10 mm in summer and 15-20 mm in winter.

5) After the socket is bonded, handle the extruded glue and wipe it clean with cotton yarn or cloth dipped in detergent.

(4)PPR tube

1) Confirm drawings: In order to carry out accurate construction, we must first know the name, specification, length, quantity and location of pipes and fittings through drawings.

2) Use a cutting machine to cut according to the service length, and the section is at right angles to the pipe axis. If it is cut by saw or other methods and then welded, there will be gaps in the welded part due to the uneven cutting surface.

3) Heat the pipes and accessories with a welding machine, and remove the dust and foreign objects on the pipes and accessories first. When the welding machine is heated to 260℃, put the pipes and accessories in for 5 seconds.

4) Welding pipes and accessories. After heating for 5 seconds, take it out, vertically align the tube and nozzle accessories, continuously press 10 for more than 2 seconds, and then cool it for more than 2 minutes.

5) Hydrostatic test before installation. Before installation, water pressure test shall be conducted at the construction site to confirm whether the welding state is good (minimum water pressure: 10kg/m2). After the water pressure test is qualified, the bad welding part should be removed.

6) Pipe handling and connection. Don't touch sharp parts during handling to avoid damaging the pipeline.

When connecting with other pipeline materials, wrap the accessories of PP-C pipe or the wire heads of steel pipes and copper pipes with adhesive tape for one to two turns, and then connect them with sealant tape for ten to fifteen turns.

2. Hydrostatic pressure test

1) Before the pipeline is concealed, the corresponding section shall be subjected to hydraulic test.

2) After the system is installed, the system water pressure test should be carried out, and the whole system can be tested in sections before the pressure test.

3) The pressure test shall comply with the design regulations, and the pressure test position shall be at the low point of the system. If placed in a high place, the test pressure should be reduced by the corresponding hydrostatic pressure.

4) Manual pressure test pump is used for hidden pressure test and equipment pressure test, and electric pressure test pump is used for system pressure test.

5) During the test, slowly increase the pressure to the test pressure, observe whether there is leakage or deformation, and then reduce the pressure to the working pressure, and keep it at 10 minute. If the pressure drop meets the requirements, it is qualified.

6) When the temperature is lower than 5℃, doors and windows should be closed, and measures such as heat preservation should be taken when necessary. If the pressure test is qualified, clean the water in the system.

3. System flushing

1) The flushing of pipeline system shall be carried out after the pipeline pressure test is qualified and before commissioning.

2) The water inlet and outlet of pipeline flushing shall be selected in appropriate positions, and the sundries in the pipeline system shall be washed clean. The cross-sectional area of the drainage pipe should not be less than 60% of the cross-sectional area of the washed pipe, and the drainage pipe should be connected to the drainage well or drain ditch.

3) Flush the pipeline with the designed flow of the system until the water color and transparency at the outlet are consistent with the visual inspection at the inlet.

4) Before flushing the system, drain the filtering device and related valves on the pipeline, and install them after flushing is qualified.

4. System debugging

System debugging is a comprehensive test after system installation, pressure test and flushing are qualified. Before system debugging, a detailed debugging plan must be made, and it should be carried out in sections and sub-items. Key components should be looked after by special personnel.

2. Project construction plan

1. Construction process of slope protection pile: drilling rig in place-drilling-pumping concrete-lifting drill-lowering casing-moving machine to the next pile position.

The main construction method: the construction technology of pumping concrete with long spiral holes is adopted, and the steel bars are inserted into the reinforcement cage by advanced vibrating method. This method is developed from CFG pile pressure grouting technology. After concrete pouring, the reinforcing cage is combined with the vibration hammer of the pipe pile driver, and the vibration force is transmitted to the bottom of the reinforcing cage through φ 127 steel pipe, and the reinforcing cage is vibrated into the hole by the vibration force, and then the vibration hammer and the steel pipe are pulled out. This construction method is efficient, pollution-free, and the concrete of the pile body is dense, which can fully ensure the quality of the pile. In order to ensure the pile quality, the construction method of every ten jumps is adopted.

Anchorage structure:

Process flow: pore-forming-binding main reinforcement-inserting main reinforcement-grouting-installing pad or waist beam-waiting for seven days for solidification-stretching-locking.

Main construction method: prestressed anchor construction should be carried out after earthwork excavation reaches the required elevation of the designed anchor hole. After the hole is formed, lower the prestressed anchor cable and grout it. When the curing age of the anchor rod reaches, the anchor rod is tensioned and locked, and the next earthwork excavation can be carried out.

2. Uplift pile engineering

Construction of rotary drilling rig. Because there are pebbles in the drilling range of this layer, rotary drilling rig is used for construction.

The uplift pile is constructed by rotary drilling rig. The rotation and gravity of drill pipe and drill bucket make soil chips enter the drill bucket. After the soil chips fill the drill bucket, the drill bucket is hoisted out, and holes are repeatedly formed through the rotation, soil cutting, lifting and excavation of the drill bucket. This method is suitable for filling soil layer, clay layer, silt layer, silt layer, sandy soil layer and stratum containing a small amount of pebbles and gravels.

After the pile location is determined, two mutually perpendicular straight lines intersect at the pile point, and cross control points are set for marking and protection. The position of the track shoe should be smooth, and the slope should not be greater than 3.

Steel lining shall be used. Before drilling, the liners should be accurately buried at the determined pile position. The length of the pile casing is about 2m, the diameter of the pile casing is greater than the designed pile diameter 10cm, the elevation of the top of the pile casing should be 20cm~30cm higher than the ground, and the wall of the pile casing should be perpendicular to the horizontal plane.

When positioning the casing, check the pile position first, and then determine the vertical cross control pile line and control the cross bolt point with the pile position as the center. The hole position of the casing should be dug and hoisted into the casing, and the pores around the casing should be filled with clay. At the same time, the center of the pile casing and the center of the pile position are corrected by the crosshair to make them coincide, and the deviation between the center of the pile casing and the center of the pile position should be less than 2cm.

Technical requirements for mud preparation:

(1) On the basis of measuring the performance of mud materials, try to match the mud mixture ratio in time.

(2) After hole formation, sample once below the mud surface and measure once after hole cleaning.

(3) The newly prepared mud should be tested before use, and it can only be used if it is qualified.

After the drilling rig is in place, aim the drill bit at the pile position, and adjust the verticality of the drilling rig after rechecking.

Before spudding, measure the elevation of the top of the hole casing with a level to control the drilling depth. When starting drilling, pay attention to the drilling speed and adjust the drilling speed in different formations.

When constructing the first slope protection pile, it is necessary to walk slowly and master the influence of the stratum on the drilling rig to determine the drilling parameters under this stratum condition.

During drilling, the mud level must be maintained, which shall not be lower than 50 cm at the top of casing. When lifting the drill, the hole should be grouted in time to ensure the water head.

Detailed drilling records must be made when drilling. Include that thickness of the main stratum and the time taken for hole formation.

When the drilling depth reaches the depth specified in the drawing, clean the hole, so that the drilling rig can idle without footage, and at the same time spray water to clean the hole. After hole cleaning, the sediment thickness is not more than 100mm, and the mud index meets the requirements.

When cleaning the hole, the water level in the hole should be kept about 50 cm below the casing to prevent the hole from collapsing.

The reinforcing cage can be hoisted manually or transported by flatbed truck and bracket on site, and the reinforcing cage cannot be permanently deformed; The reinforcing cage shall be hoisted by crane to align with the hole position, and then lowered slowly, and shall not be forced to enter. Due to the uneven stress on the reinforcing cage, attention must be paid to the direction of the reinforcing cage when hoisting, and the top of the cage on one side of the reinforcement in the groove is marked with red paint.

Catheter and funnel: choose a catheter with a diameter of 25cm. When assembling the conduit, the joint must be tight and watertight (sealing ring and butter seal are required); Before the first use, the water should be turned off and pressurized, the test pressure is 0.6 MPa ~ 1.0 MPa, and it is qualified if there is no water leakage.

The bottom of the conduit is about 50 cm higher than the elevation of the hole bottom. The funnel is installed at the top of the catheter.

Technical requirements for concrete: this project adopts commercial concrete with slump of 180 mm ~ 220 mm and initial setting time of concrete not less than 6 hours; Any admixture containing calcium chloride is not allowed to be used in concrete mixture ratio. The prepared concrete should be dense and have good fluidity, meet the underwater concrete pouring and ensure the design requirements.

This technology adopts free plug waterproof (that is, inflatable airbag), and the waterproof plug airbag should be suitable in size and straight in installation, generally above the water surface. Before pouring concrete, the orifice should be tightly covered to prevent the concrete from falling into the hole and polluting the mud. The first pouring amount of concrete should be poured to the lower opening of the conduit for more than 2m; When pouring concrete, the depth of the lower opening of the conduit into the concrete shall be not less than 1.5m and not more than 6m.

Assign a special person to measure in time, so as to master the lifting height of the catheter. Every time the conduit is dismantled, the buried depth of the conduit should be measured and calculated, and then the length of the conduit should be determined to keep the concrete in a flowing state, and the pouring construction records should be made. Concrete pouring must be carried out continuously without interruption.

When the concrete surface approaches the lower end of the reinforcing cage, in order to prevent the reinforcing cage from floating, when the concrete surface approaches and enters the reinforcing cage for the first time, the depth of the conduit should be kept large and the pouring speed should be slowed down. When the concrete surface enters the reinforcing cage, the conduit should be raised appropriately and the buried depth should be reduced (not less than 1.5m) to increase the buried depth of the reinforcing cage under the conduit mouth.

When the concrete is poured into the upper part of the pile hole within 5m, the conduit cannot be lifted again until it is poured to the design elevation and then pulled out again. After concrete pouring is completed, the liners should be pulled out in time and covered with backfill immediately to prevent hole collapse and protect the safety of personnel and equipment.

In the process of pouring underwater concrete, a sewage pump should be set to drain water in time to prevent mud from overflowing and ensure civilized construction.

Note: When lifting the conduit, no more than 5 connecting joints shall be lifted at one time. The catheter should be cleaned immediately after use.

Due to the construction in the pit, road slag should be properly laid according to the actual situation to ensure the normal construction of the pile driver.

In addition to pile foundation construction in strict accordance with the requirements of relevant codes, in order to ensure the quality of uplift piles, low-strain dynamic testing should be carried out, and the number of random inspections should be no less than 20. Static uplift test of single pile shall be carried out for pile foundation, and the number of inspection shall be 1% of the total number of piles, and not less than 3 piles.

3. Conclusion

The foundation pit can be excavated stably under the condition of uphill and downward support, and good results have been achieved, which plays a vital role in the smooth progress of the project.

3. Project construction plan

1. Construction preparation 1, level the site, and clean up 30cm humus soil, tree roots, turf and other sundries on the surface. Leveling the original ground in rugged areas. Independent pit as a working face alone, according to the requirements of supervision engineer, layered compaction to the original ground. Rolling loose soil layer on the surface. Build mechanical access roads and drains around the construction area to ensure smooth drainage in the construction area and prevent water accumulation.

2. Take undisturbed soil for standard compaction and water content test.

3. Measure and set out, determine the control axis, impact and crush the sideline, mark the layout of measuring points in the construction area, and prepare the instruments used for settlement observation.

4. Construction equipment: impact roller, loader (tractor), bulldozer, smooth roller and grader.

5. Before construction, specify the specifications and performance of impact equipment, impact compaction and vibration compaction, and determine the detection method.

Second, the impact compaction construction method

1, construction method

A triangular impact compactor of over 25KJ is used for impact compaction, and the walking speed of impact compaction is controlled at10 ~12km/h. ..

The affected width of K8+500 ~ K9+500 section is 39.5m, and the affected area is 39500m2. The influence width of section K 13+500 ~ K 13+900 is 44.9m, and the influence area is 17960m2, which is much larger than the turning radius of subgrade. During construction, the construction site is symmetrically divided into two halves with the center line of subgrade as the center, and it is impacted and rolled back and forth. When impact rolling, start from the left outside, drive clockwise, rotate around the center of the impact compaction surface, and then roll with longitudinally staggered wheels.

2, impact rolling construction technology

1) In the impact compaction section, according to the preparation items before construction, the site shall be leveled and rolled before impact compaction.

2) Take undisturbed soil for standard compaction and water content test.

3) Measure and release the walking track of the impact compactor. According to the width of subgrade surface, determine the track direction of circular impact rolling, spread it out with grey lines, and then impact rolling with impact compactor. Impact rolling will be rolled from one side of subgrade to the other side, and the rolling sequence should be in line with the order of "two sides first, then the middle", and the entire subgrade surface should be covered with overlapping but non-overlapping tracks. After the equipment is in place, the impact roller will be towed by the tractor to speed up in the buffer zone. When passing through the test area, the driving speed will be 10 ~ 12 km/h ... The pressure relief method will be adopted for rolling. When shifting laterally, the width of each wheel of the impact roller is 0.9m, and the inner edges of the two wheels are 1. 17m. The roller is driven twice to form a rolling belt with a width of 4m. Among them, the second single wheel of each pass passes through the center of the inner edges of the first two wheels, forming a theoretical grinding gap of 0. 13m on both sides. When the second pass moves inward for the first time, all the gaps of the first pass are crushed; The third time, return to the position of the first time. Each time, the longitudinal staggered wheel circumferential distance of 1/6 is used for rolling. After rolling for 6 times, return to the position of the first time and start the second round of rolling for 6 times. Push it from one side to the other side in turn to complete all rolling times.

4) In the process of impact rolling, if the wheel track is too deep and the speed of the roller is affected, the bulldozer can be used to flatten it and continue the impact rolling. Whether dust is raised on subgrade surface during impact rolling. You can continue to wash and grind after sprinkling water properly with a sprinkler; In the process of rolling, when the water content in the soil is not enough, sprinkle water to adjust. Make it reach 3% water content.

5) Continuous impact rolling shall be carried out in accordance with Articles (3) and (4). When the last five settlements are not greater than lcm, the design requirements shall be checked.

6) If the construction quality requirements specified in the design cannot be met, repeat items (3) and (5). Until the design requirements are met.

7) After impact rolling with a smooth roller, smooth the subgrade surface.

8) 40cm7% lime-soil cushion shall be laid, and the 40cm7% lime-soil cushion shall be constructed in two layers, each with a thickness of 20cm.

7% lime soil shall be constructed by field mixing. During construction, when loading soil or lime, the number of each vehicle should be controlled to be basically equal. The loose thickness of soil should be determined by experiments. When the grader paves, its loose paving coefficient is about 1.25- 1.35, which is subject to field control and adjustment.

Use grader to spread the soil evenly on the predetermined width, the surface should be as flat as possible, and the road arch should meet the design requirements. Check whether the thickness of loose paving material layer meets the expected requirements, and reduce or supplement materials if necessary.

In the construction of lime-soil road mixing method, the lime dosage is higher than that made in the laboratory 1% to ensure that the lime dosage meets the design requirements.

Before applying lime, use a light roller to roll it properly to make its surface smooth and have a certain compactness. Then, according to the calculated vertical and horizontal spacing of lime per truck, lime is used to mark the unloading of lime on the soil layer and draw the edge of lime at the same time.

Lime should be unloaded at fixed points and inspected after unloading. After passing the test, spread the lime evenly with scraper or manual grader, and measure the loose thickness of lime. According to the water content and loose density of lime, check whether the lime dosage meets the design requirements, and supplement it if it is not enough.

Mixing should be carried out on site with road mixer for more than two times to ensure that there is no plain soil interlayer. When mixing, assign special personnel to follow the mixer and check the mixing depth at any time. When mixing, control the cutter of the road mixer to drive into the lower surface about 1cm, so as to facilitate the bonding of the upper and lower layers.

In order to ensure the construction effect, lime powder and soil must be evenly mixed and leveled, and the materials must be drilled for about 3 hours. When quicklime is mixed with soil, it will generate hydration heat due to digestion at the same time. The heat of hydration will accelerate the reaction and improve the performance of the mixture. If the compaction is too early, the hydration heat will make the structural layer swell, which will seriously affect the construction quality.

After drilling, the pressure shall be released from both sides to the center in strict accordance with the specification requirements, and the wheel tracks shall overlap more than 50cm when using vibratory roller; When three-wheel static rolling is used, the rear wheel overlap should be greater than 1/3 to ensure uniform rolling. In the process of rolling, if it is found that the local spring soil is too wet or too loose, according to its area, this part of the soil will be excavated mechanically or manually (into a regular rectangle) to the lower surface, and filled with lime soil of the same quality with water content meeting the requirements.

Third, the construction control points

1. Before impact rolling, compact the original surface with a smooth roller.

2. Use low-speed impact rolling for the first five times to avoid the impact pit being too deep, the mechanical driving being difficult and the impact rolling being uneven, which will affect the rolling effect.

3, every five times, with bulldozers, smooth roller static pressure grinding, and according to the water content, eliminate the loose soil layer on the surface.

4. After rolling for five times, the rolling speed of each time is greater than12 km/h. ..

Fourth, quality control and testing.

1, quality inspection

(1) Construction quality requirements: the settlement of the last five impacts shall not be greater than 1cm. The compaction degree of the soil below the rolling surface 1m depth shall not be less than 90%.

(2) Inspection quantity: After the impact rolling meets the design requirements, six points on two sections are inspected at equal intervals of 100m in the test area, with each section being 1 point on the left, middle and right, and the left and right points being 1m away from the subgrade edge. If it fails to meet the specified construction quality requirements, it will be rolled continuously until it meets the design requirements.

2, quality assurance measures

(1) Check the water content 20cm below the original surface. If the water content does not meet the requirements, it needs to be aired or sprinkled.

(2) When the impact roller is used for impact rolling, the wheel tracks should overlap, but not on the whole surface. In the process of impact rolling, if the surface fluctuates greatly, it will directly affect the impact rolling speed and compaction effect, so it is necessary to level it with bulldozer at any time. In addition, if the surface is too dry, water should be sprinkled in time to prevent dust.

(3) Determine the underlying geological conditions of this section of subgrade before impact rolling. If there is a soft soil interlayer 2 ~ 3m below the ground, it is not suitable for impact rolling.

(4) In the rolling process, the tractor should keep walking at a constant speed and keep the correct walking direction.