1. Engineering construction program
One, project overview
The project can be divided into: water supply and drainage works, heating works, ventilation and air conditioning works.
Second, the construction process
1, pipeline installation
Project content: pipeline placement, support bracket installation, dry pipe, riser installation, branch pipe installation, valve installation, accessory installation, anticorrosion insulation.
Pipeline avoidance: water supply, heating pipe to let the drainage pipe, heating pipe to let the heating pipe, pipe diameter small to let the pipe diameter of the pipe, pressure pipe to let the non-pressure pipeline, the process must be a reasonable configuration between the determination and adjustment of the project pipeline and bracket location.
(1) pipeline filament joint
1) filament joint for water supply pipe.
2) According to the site mapping sketches, drawing lines on the pipe, according to the line broken pipe.
3) The use of electric lasso machine, DN25mm or more to be divided into two, long tube lasso, the back end of the tube to be padded.
4) Pipeline threaded connections should be added between the inner and outer threads of the appropriate filler, generally using white thick paint oiled hemp wire, can also use raw tape.
5) Installation of threaded parts, should be installed according to the direction of tightening once, not backward. After installation, expose 2~3 teeth thread, and remove the remaining filler.
(2) pipe welding
1) welding pipe, pipe interface to remove floating rust, dirt and grease.
2) Steel pipe cutting, the cut surface should be perpendicular to the centerline of the pipe to ensure that the pipe is welded concentricity.
3) When the wall thickness of the pipe is more than 5mm, the bevel should be cut to ensure full weld penetration. Bevel forming can be cut by gas welding or beveling machine processing, but should remove slag and iron oxide, and polished with a file until the metal is exposed to light
4) pipe welding, the two pipe axis centering, the first two pipe ends spot welded fixed.
5) pipe and flange welding, the pipe should be inserted into the flange first, spot welding with an angle ruler to find the right, leveling and then welding. The flange should be welded on both sides, and its inner welding shall not protrude from the closed surface of the flange.
6) The flange should be perpendicular to the center line of the pipe, the surfaces should be parallel to each other, the flange liner shall not be convex into the pipe, the bolts connecting the flange specifications should be matched with the flange, the length of the screw protruding from the nut shall not be greater than 1/2 of the diameter of the screw.
7) Flange liner should be selected in accordance with the drawings and specifications, the cold water system uses a rubber gasket, the hot water system uses an asbestos rubber gasket.
(3) Drainage PVC pipe
1) According to the actual sample drawings of selected qualified pipe and fittings, prefabricated pipe sections. Prefabricated pipe section preparation is completed, according to the sample drawing to check the size of the node between.
2) PVC pipe and cast iron pipe connection, PVC pipe should be polished, grinding hair and then bonded with cast iron pipe.
3) The materials and prefabricated pipe sections are transported to the installation site, and the pipes, fittings and expansion joints are installed in order according to the position of the retained opening and the centerline of the pipe, and the pipe openings are connected.
4) the setup of expansion joints on the cross-trunk pipe, according to the calculation of the expansion amount to determine the cross-branch pipe on the merging fittings to the riser more than 2m should be set up expansion joints, and the distance between the expansion joints shall not exceed 4m, the pipe end into the expansion joints to leave a gap for the summer: 5-10mm, winter: 15-20mm.
5) socket bonding is completed, the processing of extruded adhesive, with cotton gauze or cloth dipped in detergent wipe clean.
(4) PPR pipe
1) Confirmation of drawings: for accurate construction, first of all, through the drawings to grasp the name of the pipeline, accessories, etc., specifications, length, quantity, location and so on.
2) use the cut-off machine, according to the use of the length of the cut-off, section with the pipe axis at right angles. If you use a saw or other methods to cut off the section after fusion, will be due to the cut-off surface is not flat so that the fusion part of the gap.
3) With the fusion welding machine to heat the tube and accessories, first remove the tube and accessories on the dust and foreign objects, when the fusion welding machine temperature to 260 ℃, the tube section and accessories into the heating for 5 seconds.
4) Fusion tube and accessories. Remove after heating for 5 seconds, align the tube and receiver attachment vertically for more than 10 seconds of continuous pressure, and then cool for more than 2 minutes.
5) Pre-installation water pressure test. Before installation, a water pressure test should be carried out at the construction site to confirm whether the fusion state is good (minimum water pressure: 10kg/m2) through the water pressure test to remove the bad part of the fusion.
6) Pipe handling and connection. Do not touch the sharp part of the handling, in order to prevent pipe breakage.
Connection with other piping materials, with tape wrapped PP-C pipe fittings or steel pipe, copper pipe fillet one to two laps, and then sealing tape ten to fifteen laps to connect.
2, water pressure test
1) Before the pipe is hidden, the corresponding pipe section should be hidden before the water pressure test.
2) After the installation of the system, to carry out the system hydraulic test, the whole system can be tested before the pressure test segment test.
3) The test pressure should be in accordance with the design regulations, the test location should be in the low point of the system, such as placed on the high side, the test pressure minus the corresponding hydrostatic pressure.
4) hidden test pressure, equipment test pressure using manual test pump, system test pressure using electric test pump.
5) test, the pressure slowly rise to the test pressure to observe no leakage, deformation, and then reduce the pressure to the working pressure, keep 10min, the pressure drop in line with the provisions of the qualified
6) If the temperature is lower than 5 ℃, doors and windows should be closed, and if necessary, to take thermal insulation and other measures. Test pressure qualified, the system to remove the water.
3, system flushing
1) The flushing of the piping system should be in the pipeline after passing the pressure test, before commissioning.
2) Pipeline flushing inlet and outlet should choose the appropriate location, and can ensure that the piping system within the debris flushing is appropriate. Drainage pipe cross-sectional area is not less than 60% of the cross-section of the pipeline being flushed, the drain should be connected to the drainage well or drainage ditch.
3) to the design flow rate of the system for pipeline flushing, until the exit of the water color and clarity and the entrance of the visual consistency is qualified.
4) The system should be flushed before the pipeline filtration device, the valve drain, to the flushing of qualified and then installed.
4, system debugging
System debugging is in the system is fully installed and pressure testing, flushing after passing the comprehensive test. System commissioning, must prepare a detailed debugging program, sub-section by sub-section. The key parts of the set of specialized care.
2. Construction Program
1. Berm Pile Construction
Process: Drilling rig in place - drilling - pumping concrete - lifting the drill - the next cage -Move the rig to the next pile
Main construction method: adopt long spiral hole pumping concrete construction technology, use advanced vibration method to insert the reinforcement cage after insertion. This method is developed on CFG pile pressure filling technology. After concrete filling, the steel cage is combined with vibrating hammer of immersed tube pile machine, and the vibrating force is transmitted to the bottom of the cage through φ127 steel pipe, and the cage is vibrated into the hole by the vibrating force, and the vibrating hammer and steel pipe are pulled out afterwards. This construction method is fast, non-polluting, and the concrete of pile body is dense, which can fully guarantee the quality of pile formation. In order to ensure the quality of the pile, the skipping method of construction is adopted.
Anchor construction:
Process: Hole formation - Tie the main bar - Insert the main bar - Grouting - Installation of mat or waist beam - Waiting for seven days to solidify - Tensioning -Locking
Main construction method: pre-stressing anchor construction is carried out after earth excavation to the required elevation of the designed anchor hole formation. After the hole is formed, the prestressing anchor cable is lowered and grouted, and after the age of anchor maintenance reaches, the anchor is tensioned and locked, and the next earth excavation can be carried out only after the end of the process.
2. Anti-drawing pile project
Rotary drilling rig construction. As there are pebbles distributed in the drilling range of this stratum, rotary drilling rig is used for construction.
This anti-drawing pile is constructed by rotary drilling rig, which utilizes the rotation of drilling rod and drilling bucket as well as gravity to make the soil chips enter into the drilling bucket, and then lifts up the drilling bucket to get out of the soil after the soil chips are filled up in the drilling bucket, so that the hole can be formed through the rotation of the drilling bucket, chipping the soil, lifting up and getting out of the soil for many times and repeatedly. This method is suitable for filling soil layer, clay layer, powder soil layer, silt layer, sand soil layer, as well as containing part of the pebbles, gravel strata.
After determining the location of the pile, two mutually perpendicular straight lines intersect at the pile point, and set out the cross control points, well marked and properly protected. The location of the tracked disk should be level and the slope should not be more than 3°.
The use of steel barrels, drilling should be measured before the pile position, accurately buried barrels, barrel length of about 2m, the diameter of the barrel is greater than the design of the pile diameter of 10cm, the top of the barrel elevation should be higher than the ground 20cm ~ 30cm, and to ensure that the cylinder wall and the vertical horizontal plane.
Positioning of the barrel should first review the pile position, and then take the pile position as the center, set out a mutually perpendicular cross control pile line, and make a cross peg control, digging the barrel hole, lifting the barrel into the barrel, the hole around the barrel filled with clay and tamped, and at the same time, the center of the barrel and the center of the pile with the crosshairs corrected, so that it is the same and to ensure that the center of the barrel and the center of the pile deviation of less than 2cm.
Preparation of slurry, the top elevation should be 20cm ~ 20cm above the ground, and ensure that the barrel wall is vertical to the horizontal plane. >
Preparation of mud technical requirements:
① In the determination of mud material properties, based on timely trial matching mud ratio.
② After the completion of the hole, take a sample below the mud surface, and measure it once after clearing the hole.
③ The newly prepared mud should be tested and qualified before use.
Rig in place, the drill bit aligned with the pile, check the correctness of the verticality of the rig after adjustment.
Before drilling, measure the elevation of the top of the hole shroud with a level meter in order to control the drilling depth. At the beginning of drilling, pay attention to the drilling speed and adjust the drilling speed for different strata.
When the first berm pile is being constructed, it should be run at a slow speed to grasp the influence of the stratum on the drilling rig in order to determine the drilling parameters under the conditions of the stratum.
During the drilling process, the mud surface must be maintained and must not be lower than the top of the shroud by 50cm. when lifting the drill, the hole must be replenished with slurry in time to ensure the head.
Drilling must make detailed drilling records. Including the thickness of the main stratum when the hole is made, the time used and so on.
The depth of the drilled hole reaches the depth specified in the drawings, clear the hole, let the drilling rig idle not to advance, and at the same time, shoot the water to clear the hole, the thickness of the slag after clearing the hole shall not be greater than 100mm, and the mud indexes meet the requirements.
When clearing the hole, the water level in the hole should be kept at about 50cm under the barrel to prevent the collapse of the hole.
Reinforcing steel cage can be manually lifted and transported or moved with a flat car with bracket, do not make permanent deformation of reinforcing steel cage; reinforcing steel cage with a crane should be lifted to the right hole, slowly down into the forbidden to force the pressure into. Because of the uneven reinforcement of the cage, the cage must pay attention to the direction of the cage when lifting and placing the cage, and the top of the cage is marked with red paint on the side of the reinforcement in the groove.
Conduit and funnel: choose the diameter of 25cm conduit, conduit assembly joints must be tightly closed without water leakage (required to add sealing ring, butter sealing); in the first time before use should be closed water pressure test, water pressure 0.6MPa ~ 1.0MPa, no leakage is qualified.
The bottom of the conduit down to the bottom of the hole elevation on about 50cm. The funnel is installed at the top of the conduit.
Technical requirements for concrete: the project uses commercial concrete, slump 180mm ~ 220mm, concrete initial setting time shall not be less than 6 hours; do not allow any additives containing calcium chloride used in the concrete ratio. The prepared concrete should be dense, with good fluidity, to meet the underwater concrete filling and to ensure that the design requirements.
The process uses a free plug water isolation (i.e., inflatable ball guts), water isolation plug ball guts should be the right size, installation should be positive, generally located above the water surface. The hole should be covered tightly before filling the concrete to prevent the concrete from falling into the hole and polluting the mud. The first amount of concrete should be filled to the conduit under the mouth of more than 2m; concrete pouring, the conduit under the mouth of the concrete buried in the depth of not less than 1.5m, not more than 6m,
set up a special person to determine the timely, in order to grasp the height of the conduit lifting. Each time you dismantle the conduit, you must measure and calculate the depth of the conduit, and then determine the length of the unloading pipe, so that the concrete is in the flow state, and make a good record of pouring construction. Concrete pouring must be continuous, no interruption.
When the concrete surface is almost to the lower end of the cage, in order to prevent the cage from floating, when the concrete surface is close to the cage and the first time into the cage, should maintain a greater depth of the conduit, slow down the filling speed, when the concrete surface into the cage, should be appropriate to enhance the conduit, reduce the depth of burying (shall not be less than 1.5m) in order to increase the cage of the conduit under the bottom of the burying depth.
Concrete filling to the pile hole within the upper 5m, can no longer lift the conduit, until the filling to the design elevation after a pull out. Concrete filling is completed in time to pull out the barrel, should be immediately backfilled to cover, to prevent the collapse of the hole and protect the safety of personnel and equipment.
In the process of filling underwater concrete, a sewage pump should be set up to prevent timely drainage of mud out to ensure civilized construction.
Note: When lifting the conduit, not more than 5 sections connected to a one-time lifting. The conduit should be cleaned immediately after use.
Because of the construction in the pit, the road dregs are properly laid according to the actual situation to ensure the normal construction of the pile driver.
In addition to the pile foundation construction in strict accordance with the relevant specification requirements, in order to ensure the quality of the anti-extraction pile, low-strain dynamic testing, sampling the number of not less than 20. single-pile anti-extraction static load test of the pile foundation, the number of inspections for the total number of piles of 1%, and not less than three.
3. Conclusion
Foundation pit in the upper sloping and lower support, the construction works can be stable excavation, get good results, for the smooth progress of the project plays a vital role.
3. Engineering construction program
I. Construction Preparation
1, site leveling, clean up the surface layer of 30cm humus, roots, turf and other debris. The original uneven ground leveling. For the independent pit as a separate work surface, and according to the requirements of the supervisory engineer layered tamping fill to the original ground. Grind the loose soil layer on the surface. Construction of machinery access road, construction area around a good drainage ditch to ensure smooth drainage of the construction area to prevent water accumulation.
2, take the original soil for standard compaction and moisture content test.
3, measurement and sampling, set out the control axis, impact crushing edge line, marked out the construction section of the measurement point layout, ready for settlement observation instruments.
4, construction equipment, impact roller, loader (tractor) a loader (tractor), bulldozer a light wheel roller and a grader.
5, before construction, clear impact equipment specifications and performance, impact compaction and vibratory compaction of the number of poo, to determine the detection method. 500～K13+900 section impact width is 44.9m, impact area is 17960m2, much larger than the turning radius of the pressure roadbed 4 times. Construction to the center line of the roadbed symmetrically divided into two halves of the construction site, back and forth impact milling, impact milling from the left side of the outside, clockwise driving, to impact the center of the compaction surface as the axis of the circle, and then according to the longitudinal staggered wheel milling.
2, impact compaction construction process
1) For impact compaction section, according to the pre-construction preparation project for impact compaction before site leveling, rolling.
2) Take the original soil for standard compaction and moisture content test.
3) Measure and put the walking track of impact compactor according to the width of the roadbed surface, determine the direction of the wheel track of cyclic impact crushing, and spread it out with a gray line, then use the impact compactor to carry out impact crushing, impact crushing from one side of the roadbed to the other side of the rushing, and the rushing order should be in accordance with the order of "two sides first, and then in the middle", with the wheel track lapping, but not overlapping the whole roadbed. But not overlap the entire surface of the roadbed for one punch grinding. Equipment in place grinding by the tractor trailer impact mill, in the buffer zone to accelerate driving, through the test area to ensure that the driving speed of 10 ~ 12km / h. Grinding using rows of pressure method. In the lateral shift, the impact roller double wheel width of 0.9m, two wheels inside the distance of 1.17m, traveling twice for one time, forming a 4m wide rolling belt. Each of the second single wheel by the first two wheels of the inner margin of the center through the formation of the theory of grinding gap bilateral each 0.13m, when the first of the second time to move inward 0.2m grinding, the first gap all crushed; the third time and then return to the first position of the position of the first time to grind. Each longitudinal staggered 1/6 of the wheel circumference spacing for crushing, after crushing 6 times to complete, back to the first position to start the second round of 6 times crushing. Sequentially from one side to the other side to complete the full number of crushing.
4) impact crushing process, if the wheel track is too deep to affect the speed of the compactor, the bulldozer can be used to level out and then continue to punch grinding. If the surface of the roadbed is dusty during the impact crushing process. Sprinkler can be used to sprinkle the appropriate amount of water to continue to punch milling; when the soil water content is not enough in the milling process, sprinkle water to adjust. Make it reach the water content ± 3%.
5) According to Article (3) and (4) continuous impact crushing, to the last 5 times the amount of settlement is not greater than lcm, the design requirements of the project testing.
6) If it fails to meet the design requirements for construction quality, then repeat (3) a (5) project. Until the design requirements are met.
7) With the light wheel roadbed press machine will be impact crushing after the roadbed surface grinding and leveling.
8) laying 40cm 7% gray soil bedding, 40cm 7% gray soil bedding construction when two layers of construction, the thickness of each layer of 20cm.
7% gray soil using field mixing method for construction, construction, soil or lime loading, should be controlled by the number of each car is basically equal. The loose paving thickness of the soil should be determined by test. When paved by grader, the loose paving coefficient is about 1.25-1.35, which is controlled and adjusted on site.
Use the grader to evenly spread the soil on the predetermined width, the surface is trying to be smooth, and the road arch meets the design requirements. Check that the thickness of the layer of loose paving material meets the expected requirements and, if necessary, reduce or make-up work.
Lime soil road mix method of construction, the dose of lime should be 1% higher than the mix ratio made by the laboratory, in order to ensure that the amount of ash to meet the design requirements.
Before applying lime, the surface should be properly compacted with a light roller to make the surface smooth and have a certain degree of compactness. Then, according to the calculated vertical and horizontal spacing of each car of lime, use lime to make the mark of unloading lime on the soil layer, and at the same time delineate the edge line of lime.
Lime unloading at regular intervals, after unloading the car for checking the square, qualified, with a scraper or grader with artificial lime spread evenly, measuring the thickness of the lime loose paving, according to the moisture content of the lime and loose density, check whether the lime dosage to meet the design requirements, not enough to be supplemented.
Mixing using road mixer for on-site mixing, mixing more than two times to ensure that there is no soil sandwich phenomenon. In the mixing process, a person is assigned to follow the mixing machine to check the mixing depth at any time. When mixing, control the road mixer knife tool into the lower surface of about 1cm, in order to facilitate the upper and lower layers of the `bonding.
In order to ensure the construction effect, lime powder and soil mixing and leveling, must be bored about 3h. Lime and soil mixed, in the occurrence of intense chemical at the same time will produce hydration heat due to dissipation, hydration heat to accelerate the reaction, can improve the performance of the mixture, if the milling molding is too early, the hydration heat will make the structural layer of swelling loose bulging, seriously affecting the quality of construction.
After smothering the end of the material, rolling strictly in accordance with the specification requirements from both sides to the center of the row pressure, the use of vibratory roller wheel track overlap more than 50cm; the use of three rounds of static milling, the rear wheel should be overlapped by more than 1/3, to ensure that the rolling uniformity. In the process of rolling, if you find local over-wet spring soil or over-dry loose, according to its area using mechanical or manual excavation of this part of the soil (dug into a regular rectangle), until the surface of the lower layer, with the moisture content to meet the requirements of the same quality of gray soil replacement fill pressure.
Third, construction control points
1, before impact crushing, the original surface compaction with a light wheel roller.
2, impact crushing before the first five times with a low-speed punch mill, in order to avoid the impact of the pit is too deep, mechanical driving difficulties, uneven punch mill, affecting the effect of crushing.
3, every five times of crushing, bulldozer leveling, light wheel roller static grinding, and according to the water content of water sprinkling, in order to eliminate the surface of the loose soil layer.
4, after five times of rolling, each rolling at a speed greater than 12km / h rolling.
Fourth, quality control and testing
1, quality testing
(1) construction quality requirements: impact milling the last five times the settlement shall not be greater than 1cm. 1m depth range under the milling surface of the soil compaction is not less than 90%.
(2) the number of tests: impact rolling to meet the design requirements, in the test area every 100m equally spaced check 2 sections of 6 points, each section of the left, center, right each 1 point, the left and right points from the edge of the roadbed lm place. If it fails to meet the specified construction quality requirements, then continue to crush until it reaches the design requirements.
2, quality assurance measures
(1) check the original surface of the following 20cm at the moisture content, if the moisture content does not meet the requirements, need to do drying or sprinkling treatment.
(2) When impact compactor is used for impact crushing, the wheel tracks are lapped but not overlapped to cover the surface once. In the process of impact crushing, if the surface appears large undulation, will directly affect the impact crushing speed and compaction effect, it is necessary to use bulldozers to level at any time. In addition, if the surface is too dry, you need to sprinkle water in time to prevent dust.
(3) impact milling before determining the section of the roadbed lying geological conditions, such as the ground below 2 ~ 3m there is a soft soil interlayer, it is not suitable for impact milling.
(4) The tractor should keep walking at a constant speed and in the right direction during the rolling process.