Familiarize with the design drawings, information, and clarify the pipeline layout of the main and branch pipe, direction and process flow and construction and installation requirements.
Familiarize with the site situation, understand the design pipeline along the existing plane and elevation control points distribution.
According to the pipeline plane and the existing control points, and combined with the actual terrain, do a good job of organizing the measured data, drawing the measured sketch.
After entering the site, the level and guide line points handed over by the construction unit will be re-tested, and after the closing difference meets the design requirements, the encryption of guide line points and level points will be carried out, and there will be one level point within every 60 meters, and the encrypted points must be closed and leveled, and the closing difference of level points will be 20 √L, to make sure that the encrypted points will be accurate, so as to satisfy the precision of the elevation of drainpipe and the line type control.
Since the pipeline centerline piles will be dug out during construction, the construction control piles will be measured and set in the place which is not interfered by construction, convenient to measure and easy to protect, the centerline direction control piles will be measured and set by extension line or wire method, and the location control piles of accessory structures will be measured and set by rendezvous method or parallel line method.
Measurement during the construction process is mainly to determine the bottom elevation, mechanical excavation, the use of follow-up measurement, with the digging measurement, to eliminate the phenomenon of over-excavation, to ensure that the bottom elevation of the trench in line with the design requirements, after the installation of pipelines, retesting, and found that the problem of timely treatment, so that the bottom elevation control in the permissible range of deviation. Every day before the start of the measurement work, should be adjacent to the level review measurement.
The center of the pipeline is determined by the centerline control pile, and the pipeline laying position is determined by hitting the side line on the pipeline foundation through the control pile.
The elevation of the well chamber is controlled according to the design requirements, and after the pipeline is laid, the completion review measurement of the top of the pipeline and the structures is carried out.
Trench excavation and foundation treatment:
Familiarize with the drawings, according to the design of the given level and coordinate control points for measurement, positioning, placement, lead to the temporary level and control piles, by the supervisory engineer review and certification approval before the trench excavation.
The project adopts excavator to excavate, the trench excavation should strictly control the digging depth and pipeline centerline, the mechanical excavation leave 20cm of margin, by manual clearing to the bottom of the trench to design the position of elevation, and the mileage piles will be led to the bottom of the trench.
Strictly control the trench excavation slope coefficient, according to the design of the slope coefficient to dig enough width, excavation should pay attention to the trench soil condition, if necessary, should ask the resident supervisor and the party and design representatives to determine the slope coefficient, in order to prevent the trench side of the collapse.
Trench excavation of earth directly loaded trucks for transportation, transportation site designated by the owner.
When the trench excavation meets with groundwater, set up drainage ditch and water collecting pit, do the groundwater drainage and precipitation work in the trench in time, and take the foundation reinforcement measures by first laying pebbles or gravel layer (thickness of not less than 100mm); when there is no groundwater, the soil under the foundation is compacted with compaction coefficient of more than 0.95; when there is silt, miscellaneous fill and other weak foundations, use the grade-graded gobi soil to replace the soil in accordance with the requirements of pipeline treatment. Graded Gobi soil replacement treatment; replacement thickness of 30cm.
After the trench is excavated for about 100 meters, the soil is transported out and cleaned artificially, and passed by the supervising engineer's inspection, the construction of the next process can be carried out in the trench.
Drainage of double-wall corrugated pipe introduction
Drainage of HDPE double-wall corrugated pipe is the main raw material of polyethylene resin, add the appropriate amount of additives, through the extrusion molding, suitable for outdoor drainage of buildings and municipal sewage with a new type of pipe. It has the advantages of light weight, low drainage resistance, high compressive strength, corrosion resistance, convenient construction, etc. It is an ideal material to replace cast iron pipe and cement concrete pipe.
HDPE structural wall pipe than cement socket pipe shows more economic and social benefits:
One, greatly shorten the construction period and reduce the construction difficulty:
Since the quality of the HDPE double-wall corrugated pipe is much lighter than the cement pipe, it is very easy to socket, so it greatly reduces the difficulty of the construction; and the HDPE double-wall corrugated pipe is as short as 6 meters a pipe, while the cement pipe is 2.5 meters a pipe, greatly reducing the construction difficulty; and HDPE double-wall corrugated pipe for the shortest one, while the cement pipe is 2.5 meters a pipe, greatly reducing the construction difficulty. 2.5 meters one, greatly shorten the construction period.
Two, HDPE double-wall corrugated pipe on the bottom of the trench is not high
Because of the cement pipe is a steel pipe, in order to ensure the effect of the socket, the bottom of the trench must be dealt with flat, it is best to play the foundation layer, and requires the construction personnel to have an absolute sense of responsibility.
The HDPE double-wall corrugated pipe is a flexible pipe, the bottom of the trench is not high requirements.
Three, HDPE pipe on the ground sinking or crustal changes do not break;
HDPE pipe elongation for steel pipe more than 20 times, is six and a half times of PVC, its elongation at break, but very high, strong elongation. This means that when the ground is sinking or hairy earthquakes when there are changes in the earth's crust, HDPE pipe can produce resistant deformation without breaking. This is far superior to steel pipes and also to PVC pipes, which are significantly more brittle. This performance has been proved at home and abroad (Japan's Great Hanshin Earthquake did not cause the pipe fracture; HDPE pipe in the Zhinan Baoshan earthquake did not destroy are proof).
Four, HDPE pipe permeability is much lower than cement pipe, less than 2%, the groundwater will not cause secondary pollution;
Cement pipe is not flexible, although equipped with a rubber ring, but the sealing effect is poor, especially the construction workers due to the weight of the cement pipe, not good construction, so no matter what the effect of the insertion of the socket, resulting in the loss of the role of the rubber ring, so as to make the pipe permeability increase.
Fifth, HDPE pipe service life is long, more than 50 years.
PE pipe safety to make the period of more than 50 years, which has not only for the international standard and the new international proof, and has been proved by the advanced countries. Cement pipe theoretical service life of 20 years, but its silicate class, long-term corrosion by acid and alkali, life greatly reduced. All over the country there are cement pipe due to sewage leakage caused by ground subsidence, interface fracture, within a few years will have to replace the example.
Sixth, HDPE pipe smooth internal surface, without positive and negative electric core, not scaling.
Cement pipe is easy to scale, scaling, so that the pipe diameter is reduced, affecting the throughput.
Seven, HDPE light weight, easy to transport and installation, no loss;
Cement pipe quality is heavy, not easy to transport and installation, and easy to lose in the transportation and installation.
Eight, when the pipeline through the flow, slope and burial depth of the same, HDPE can be smaller than the cement pipe one or two models;
HDPE inner surface roughness coefficient of 0.009, the cement pipe inner surface roughness coefficient of 0.014, in accordance with the world-recognized Xie Cai law, the same flow calculation, HDPE pipe can be smaller than the cement pipe two models, and the practical applications In the actual application, it is recommended that a small model can be. Such as the design of 600 caliber cement pipe can be replaced with 500 caliber HDPE.