Weak current College】 【municipal sewer construction project quality common failing preventing.

<br> <br> Drainage system is its service area to other engineering facilities normally use one of the essential facilities to ensure that its quality is essential. The author according to the years engaged in the construction of the technical work experience on municipal sewer construction .quality common failing of a comprehensive analysis. The most common quality problems are divided into four areas, analysis of its causes, and propose measures for colleagues. <br> <br> 1 pipe location offset or ponding <br> <br> 1.1 causes .: <br> <br> Construction of measurement errors, discrepancies and accident avoidance, the original structure on a flat surface where offset arise, facade on the water and even slope. <br> <br> 1.2 preventive measures: <br> < .br> (1) prevention of measurements and construction defect resulting from measures: ① pre-construction conscientiously follow construction norms and rules for measuring over piles of repetition and protection. ② construction survey in conjunction with hydrological conditions, in accordance with depth and design requirements .and the relevant provisions of the loft, and repetition test must be carried out in compliance with the requirements of its error after the delivery of construction. ③ the construction to be carried out in strict accordance with the specimen in piles, Groove Peace Foundation to do .the measuring axes and longitudinal slope. <br> <br> (2) if the accidents during construction shall be avoiding encountered structures, should, where appropriate, additional connection well connected in a straight line connecting corner should be greater than 135 °. < .br> <br> 2 pipeline leakage, closed water test failed <br> <br> 2.1 causes: <br> <br> Basis of uneven subsidence, pipes and construction of the poor quality of interfaces, closed water segment end sealing tightly, .well in poor quality construction and other reasons may produce leakage phenomenon. <br> <br> 2.2 prevention measures: <br> <br> (1) pipeline infrastructure side will result in the pipeline and the Foundation appears uneven subsidence caused local water, .General, severe fault occurs or interface crack pipe. Preventive measures are: ① seriously as designed construction, ensure that the pipeline based on the strength and stability. Local hydrological conditions adverse base of quality should be for the treatment of soil improvement to increase carrying capacity .at the bottom of the base channel. ② If tank bottom soil is disturbed or is affected by water immersion, you should dig in addition to the soft soil and sand over-excavation part or gravel and other stability good material backfill dense. ③ groundwater following .excavation Earth, should take effective measures against tank bottom drain precipitation and ensure that the dry excavation, if necessary, in the Groove bottom 20cm thick layer, reserved pending subsequent processes of construction with digging with closed. <br> <br> (2) .pipe quality difference, there are cracks or local concrete loose, poor impermeability capacity, the capacity to produce water. Therefore requires: ① the pipe to provide quality certificate and mechanical test reports, etc. ② pipe surface appearance quality requirements without loose explicit and voids ., hard objects tapping the tube wall melodic sound of it. ③ the pre-installation check-by-section again, to have found or have quality questions should be abandoned or effective treatment before use. <br> <br> (3) management .interface packing and poor quality construction, pipeline at external force under breakage or interface crack. Control measures: ① selection of good quality and test interface stuffing mix and reasonable construction construction technology organizations. ② interface joints internal to clean, to cement class padding interface also .advance moist, but prior to the oily, dry brush cold base oil, and then follow the construction construction practice seriously. <br> <br> (4) poor quality inspection Chamber construction, the wall and the combination of its connecting pipe leakage, .precautions: ① manhole masonry mortar to full, the filler full not omitted; wipe clean the surface before and moist, plastering, timely press light your pulp and conservation; in case of groundwater, plastering and filler should be completed in a timely manner with masonry ., not backfill later in the hand or crooked seams. ② and to check well connected pipe outer surface should be moist and evenly brush a layer of cement mortar, and block size in place and then do a hand inside to prevent leakage. <br> .<br> (5) closed water seal not dense, and because of its well but often neglected, if the brick wall block, you should note the following points: ① masonry wall before the spout 0.5m about range of tube wall clean, brushing .cement mortar, wetting the brick. ② masonry wall mortar labels should not be less than M7.5, and good consistency. ③ filler and plastering of mortar labels not lower than the M15. The larger the diameter should be smaller and external double-sided ., one side only or plaster filler. Wipe surface should be waterproof 5 layer construction method. «1 2600 ④ conditions allow to check well before a block of masonry, to guarantee quality. ⑤ preset drainage holes in the bottom inside the tube to drain and .test checks. <br> <br> (6) closed water test for pipeline construction and material quality for comprehensive testing, the inevitable three failed twice. In this case a leaks a notation, in well drain tube water after careful processing. On the .small gaps or voids and leakage may use cement coating or waterproof paint Daubs, more serious should rework process. Ointment for using torch interface surface treatment, usually pooled effect, otherwise uncover refill. Serious leakage in addition to the replacement of pipes and back fill interface ., you can see professional and technical personnel. After doing the test, so duplicate until closed water qualified. <br> <br> 3 check the shaft deformation, sink, poor quality parts <br> <br> 3.1 causes <br> < .br> Manhole deformation and sink, well cover quality and installation quality is poor, iron ladder install arbitrary is too large to affect the appearance and quality. <br> <br> 3.2 prevention measures <br> <br> (1) do the .inspection well's grass-roots and cushion, broken pipe do chute approach to prevent logging of sinking. <br> <br> (2) the inspection well laying quality should control the shaft, and the mouth of the central location and height to prevent well .body deformation. <br> <br> (3) manhole covers and housings should be coordinated; installation block size to the full; the severity of the model and surface bottom right, iron climbing installation to control the good, the location of the first .step, the error will not be too large, flat position accuracy. <br> <br> 4 the backfill soil subsidence <br> <br> 4.1 causes <br> <br> Compaction machines are not appropriate; packing quality is poor, .the moisture content of the control is not good, affect the compaction results, give workers resulting excessive sedimentation. <br> <br> 4.2 prevention and treatment measures <br> <br> 4.2.1 prevention measures <br> <br> ① .ducts must fill the site under backfilled and construction conditions appropriate packing and pressure (RAM) real machines. If the main drainage facilities under the pit-sand backfill is used. Pipe Groove from pleural parts reclamation-tube top irrigating vibrating 30cm, then to relative .density ≥ 0.7, practice has shown that the effect is pretty good. ② pipe Groove narrower when using miniature roller filling pressure or artificial and breaststroke ramming machine tamping. Different media, different filling thickness should use different tamping pressure apparatus, in order to obtain the .most economic effect of the compaction. ③ packing of sludge, the roots of plants, turf and corruption affects both compaction effect, and in soils shrinkage, rotten hole formation, these materials may not be packed so as not to cause subsidence. ④ control fillings .is greater than 2% of the optimum moisture content; in case of ground water or rain after construction must drain the water and then layered with filled with pressure-dense; eliminate with water the backfill or water consolidation construction. <br> <br> .4.2.2 treatment measures <br> <br> According to the settlement of destruction, adopt the appropriate measures: ① does not affect the other structures of a small settlement may not be processed or only surface treatment, such as asphalt pavement can be taken .to avoid partial fill. ② as causing other structure based on the detachment failure may use the pump pressure slurry fill. ③ If caused structural damage that should be digged bad packing, filling stability good material, compacted and then restore the damaged structures. <br .> <br> 5 conclusion <br> <br> Piping works, which are concealed work, it only checks for well completion for people to test. Therefore, the inspection of construction quality often dictates the overall assessment of the quality of the project. .Nevertheless, the author believes that the drainage pipe engineering excellence must be built on the main structure of engineering excellence. In the construction process should strive to overcome various problems, ensure that the overall project construction quality to achieve excellent and the inspection well construction quality even .better, thus achieving excellence objectives. <br> <br> <br> <br>.