Analysis of key points in urban sewage pipe network construction management?

What is the specific content of the analysis of the key points of urban sewage pipe network construction management? Zhongda Consulting will answer it for you below.

In the construction of urban infrastructure, sewage pipe network projects are an effective means to strengthen the modernization process of the city, improve the pace of urban development, and reduce environmental pollution. Scientific and effective management of sewage pipe network projects is a prerequisite for ensuring project quality and improving project efficiency. Therefore, construction units must pay attention to the construction management of sewage pipe network projects, and take effective measures to strengthen management and improve management levels.

1 Characteristics of sewage pipe network projects

(1) It is located on both sides of urban roads, close to various buildings, and has many people passing by.

(2) There are many obstacles on the ground, various underground pipelines are intertwined, and the coordination workload is large.

(3) Sewage is basically gravity drainage, and the elevation requirements for the sewage pipe network are relatively high.

(4) The trenches of the sewage pipe network are deep and there are many safety hazards.

(5) Sewage contains various harmful substances. In order to avoid contamination of groundwater, the strictness of the pipe network is required.

(6) Sewage pipe network projects often require the original sidewalk to be demolished or located under a new sidewalk. In order to avoid future ground depressions, high requirements for backfill soil are required during construction.

2 Basic requirements for construction management of sewage pipe network projects

(1) Identify various obstacles on the surface and underground that may affect construction to avoid damage to other structures. causing the project to stall.

(2) According to the control points of the planning department, complete the intersection of elevation points and central piles, and conduct retesting of the control points to ensure that the reference points are correct.

(3) Safety management must be carried out unremittingly and throughout.

(4) Each branch and sub-project should be checked at all levels. Only after passing the acceptance inspection can the next process of construction be carried out.

(5) Organize the three major acceptance inspections of trench, water closure and completion.

(6) The construction data are synchronized with the construction progress and are true, valid and complete.

3 Key points of construction management of sewage pipe network projects

The municipal sewage pipe network starts from the on-site pile delivery, and successively undergoes on-site survey, trench laying, trench excavation, and trenching. There are 11 links including acceptance, cushion construction, pipeline installation, pipeline protection (pipe protection sand or concrete pipe shoulder) construction, inspection well construction, closed water test, trench backfilling, and completion acceptance. The construction content of each link is as follows.

3.1 On-site pile delivery

On-site pile delivery is the work of the construction unit delivering the location and data of the elevation point and center point to the construction unit. On-site piling is one of the important preparations before the construction of the sewage pipe network project. Its elevation point and center point are the basic elements to guide the construction of the project. During the construction, we must strive to: First, the on-site piling point must be determined by the planning department. Secondly, the on-site intersection point must be re-tested, and its closing error must be within the specified error range; thirdly, the on-site intersection point must be protected, and if necessary, it can be led to a safe place for protection.

3.2 On-site reconnaissance

On-site reconnaissance is to conduct on-site inspection of the terrain along the sewage pipe network, explore surface objects and underground pipelines, and accumulate sufficient data for the formulation of construction plans. The on-site survey should mainly do the following tasks: first, re-measure the relevant terrain and draw it into maps to accumulate data for completion settlement; second, measure or measure the obstacles such as walls, buildings, trees, etc. that affect the construction of the pipeline network. The quantity shall be counted and reported to the construction unit and relevant departments for approval in a timely manner. After the increased project quantity is registered and confirmed, various coordination and demolition work shall be carried out promptly.

3.3 Trench setting out

Trench setting out means that the construction unit will set the center line of the pipe network, the width of the trench bottom and the width of the top of the trench according to the drawings and on-site intersection points. Sprinkle with white ash.

The key points of quality control are: first, release the center line strictly according to the intersection point; second, release the wide gray line at the bottom of the trench according to the requirements of the drawings, atlases and "Code for Construction and Acceptance of Water Supply and Drainage Pipeline Projects"; third, release the wide gray line at the bottom of the trench according to the soil quality. situation, in accordance with the requirements of the "Construction and Acceptance Specifications for Water Supply and Drainage Pipeline Engineering", after calculating the grading width, release the trench excavation edge lines; fourth, report the placed center line, trench bottom width line, and trench excavation edge lines. The supervision unit and the construction unit shall conduct inspection and acceptance, and trench excavation can only be carried out after the inspection is correct.

3.4 Trench excavation

Trench excavation is one of the most important links in the construction of sewage pipe network. The quality of trench excavation directly affects subsequent trench acceptance. At the same time, deeper trenches bring more safety hazards. The following points should be kept in mind during construction: first, excavate strictly according to the laid out edges; second, a 200-300mm thick soil layer must be reserved during mechanical excavation, which must be cleaned manually to prevent disturbance to the original soil; third, use Levels and theodolite are used to measure the elevation and centerline to ensure that the elevation and centerline positions are accurate; fourth, grading is performed in accordance with specifications. If it is determined that grading cannot be done due to terrain restrictions or the grading is not in place, the approved support plan must be followed Support the trench wall; fifth, the pile of soil beside the trench should not be too high, and the minimum distance between the edge of the pile and the trench wall should not be less than 0.8m, and the excess soil must be transported away first; sixth, after the trench is excavated and Safety enclosures must be implemented along the construction line to prevent nearby people from accidentally entering and causing safety accidents.

3.5 Trench acceptance

Trench acceptance is carried out by the supervision unit, construction unit, design unit, construction unit, It is carried out with the presence of the geological exploration unit and other participating and supervisory personnel. It is one of the three major acceptance inspections of the sewage pipe network project. The basic conditions for trench acceptance are: complete construction data; safety protection measures in place; trench bottom width, elevation, flatness, grading, etc. meet the requirements; and the main person in charge of each participating unit is present. The basic process of trench acceptance: re-test the trench width, elevation, etc. during on-site acceptance; check the flatness of the trench bottom; check the safety measures at the construction site; after meeting the requirements, all participating units sign for confirmation.

3.6 Cushion construction

Quality control requirements for sand cushion construction: the particle size must meet the medium-coarse sand standard; first hang the line and then spread the sand to ensure uniform thickness and the slope meets the requirements. Quality control requirements for concrete cushion construction: width and thickness comply with drawings or atlas requirements; strict measurement to ensure accurate concrete mix ratio.

3.7 Pipe installation

Construction quality requirements for double-wall corrugated pipes: Install them sequentially from downstream to upstream, with the socket consistent with the direction of water flow; place rubber rings according to the requirements of the drawing, and the socket should be in line with the flow direction. Apply lubricant to the spigot, and use a pipe tightener or guide chain to connect two adjacent pipe sections together with even force; during installation, adjust the pipe sections in time according to the center line, and always keep the pipe straight and the center line of the pipe coincident with the center line. Quality requirements for cement pipe construction: hoist the pipe to the trench, leaving a 10mm expansion joint between the pipes; adjust the position of the pipe according to the center line to keep the center of the pipe coincident with the center line. 3.8 Pipe protection sand and concrete pipe shoulder construction quality control

After the installation of the double-wall corrugated pipe, pipe protection sand should be applied on the pipe side and top. The pipe base must be within the range of 900 or 1200 or 1800. Coarse sand should be filled firmly. During the backfilling process, materials should be removed from both sides of the pipe at the same time to ensure that the installed pipe does not shift; medium coarse sand, fine sand or fine soil that meets the requirements can be used for backfilling within 500mm above the top of the pipe. After the concrete pipe is installed, the concrete pipe shoulder, embedded steel wire mesh, inner wiper opening and outer wiper pipe belt should be cast using formwork. The basic requirements are: the width of the pipe shoulder, the width and thickness of the wiper tape should meet the requirements of the drawing; the embedded depth and width of the steel mesh should meet the requirements of the drawing; it is recommended that the inner wiper mouth be filled with a semi-dry cement and sand mixture; the external wiper should be filled with a semi-dry cement and sand mixture. The width and thickness of the mouth should meet the requirements of the drawing and the surface should be smooth and calendered.

3.9 Inspection well construction

The inspection well is an important structure in the sewage pipe network project. The quality of its masonry and plastering directly affects the results of the closed water test.

The following points should be controlled during the construction: first, the masonry mortar should be full; second, the ladder should not be stepped on when going up and down the well during the masonry process to avoid loosening the ladder; third, the construction should be carried out according to the drawings to ensure the closing position of the inspection well. and the direction is correct; fourth, the inner and outer plastering should be done twice, and an appropriate amount of waterproofing agent should be added as required; fifth, special attention should be paid to the treatment of the roots of the inspection wells. Before masonry, the base should be cleaned and painted with plain slurry; when plastering, the chute in the well should be consistent with the cross-sections of the upstream and downstream pipes.

3.10 Closed water test

The closed water test is the second major acceptance check in the construction of sewage pipe network. The closed water test can only be carried out after the construction data are complete and the test pipe section has been filled with water for 24 hours. The basic conditions for the closed water test are: the certificates and inspection reports of all incoming raw materials are complete; the incoming raw materials that need to be retested pass the test; there is a mix ratio of concrete and mortar; the acceptance of each sub-project is qualified; the self-inspection of the closed water test is qualified; The test pipe section was filled with water for more than 24 hours and the upstream water head reached 2 meters; the water injection container met the requirements. Closed water test procedure: draw a red baseline on the water surface inside the first upstream inspection well, and start timing at the same time. The water level will drop and replenish within 30 minutes, and the total water replenishment amount will be accumulated by 30 minutes; observe each inspection well and pipe section Whether there is water seepage in joints and pipe sections, the standard is qualified if there is no obvious leakage; calculate the actual measured water seepage amount and compare it with the specification requirements. If the amount of water seepage is less than or equal to the allowable water seepage amount in the specification, it is qualified.

3.11 Trench backfill

Trench backfill should be compacted in layers. The following points should be controlled during backfilling: the thickness of layered virtual paving should not exceed 250mm; the backfill soil should be sampled and tested as required; special attention should be paid to the backfilling around the well; phenomena such as ultra-thick paving and direct mechanical pushing of soil into the trench should be strictly avoided .

3.12 Completion acceptance

Completion acceptance is the third major acceptance of sewage pipe network construction. The sewage pipe network can only be put into use after passing the completion inspection and acceptance. The following information should be provided for completion acceptance: as-built drawings and design change documents; certificates and test records of main materials and products; pipeline location and elevation measurement records; closed water test records; intermediate acceptance records; inspection records of backfill soil compaction . The main contents of the completion acceptance are: checking the completion acceptance data; pipeline location and elevation; cross-sectional dimensions of the pipeline and ancillary structures; appearance inspection. All the above contents meet the requirements, and the completion acceptance will be regarded as qualified.

4 Safety management in sewage pipe network construction

The sewage pipe network project has deep trenches and long lines, and there are many safety hazards. A little carelessness can easily cause casualties to workers and other personnel. Whether safety management work is in place directly affects the progress, quality and investment of construction. Therefore, safety management is the top priority in sewage pipe network construction. The key points of safety management work are as follows.

(1) Provide protection along the construction line and hang safety warning signs.

(2) Slope shall be constructed according to the requirements of the specification. If the slope cannot be graded, it must be supported.

(3) The pile of soil beside the trench should not be too high, and there should be sidewalks of no less than 0.8m along both sides of the trench.

(4) There should be safety ladders of sufficient length and strength in the upper and lower trenches.

(5) Strengthen slope monitoring. If cracks and other abnormal conditions are found, the site should be evacuated in time. Construction can only continue after the hidden dangers are eliminated.

(6) Strengthen safety education and safety technology briefings, and ensure personal protection.

(7) Strengthen construction safety management during winter and rainy periods to prevent accidents such as frozen soil collapse or rain erosion and collapse.

5 Conclusion

As an important part of urban public works, the municipal sewage pipe network project is a basic component of urban functions. Sewage is collected through the sewage pipe network and discharged after treatment. , to avoid the random discharge of sewage and protect the ecological environment. Therefore, controlling the construction quality of sewage pipe network projects is directly related to the image and environment of a city, and directly affects the lives of urban residents. Therefore, only by doing a good job in pre-construction preparations, checking the quality of each sub-project at all levels, and completing the three major acceptance checks can we control the construction quality and do a good job in construction management.

For more information about engineering/service/purchasing tender document writing and production to improve the bid winning rate, you can click on the official website customer service at the bottom for free consultation: /#/?source=bdzd