Combine the formwork with the steelformwork and the wood formwork, remove all the sundries, strictly match theratio, and leave the test block for inspection. Each pier must be poured onceand inserted every 300~500mm thick layer. The vibrating rod is vibrated at thetop. Then clean up the site and carry out maintenance.
Temporary brackets used in pipelineinstallation shall be removed when the strength of the buttress reaches 75% ofthe design number. In the case of groundwater, a 100mm thick gravel mixed sandcushion should be laid at the bottom of the buttress.
Masonry of valve wells
(1) Including valve wells, drain valvewells, masonry of silt wells and pouring of well covers
(2) Foundation pit excavation: the slope offoundation pit excavation can be adjusted according to the nature of the soil,generally not more than 45 degrees. After the foundation pit is excavated tothe elevation, the foundation soil can be dug deep when it is soft silt soil.Dig into the old soil or the general silt, and then backfill it with the mediumcoarse sand to the design elevation.
(3) When valve well masonry and wellchamber pouring, except for the bottom plate, the pipe shall be laid after thepipe is installed, and the interface and flange shall not be poured outside thewell, and the distance from the well wall and the wellhead shall not be lessthan 0.25. m. In the rainy days, the wells should be built in the pipeline, andthey should be built together to prevent the rainwater from entering the welland blocking the pipeline.
(4) The construction of the brick roundinspection well shall be carried out after the pipeline is installed, firstly,the concrete floor shall be poured according to the design requirements, andthe well body shall be built after the strength of the concrete is greater thanor equal to 5 MPa.
(5) After cleaning the foundation withwater, first lay a layer of mortar and then press the brick to build it. Itmust be fully covered. The gray joint between the brick and the brick should bekept 25px. The brick joint should be full of mortar and smooth.
(6) When pouring in the well chamber, thesteps must be installed synchronously, and the position should be accurate.After the step is installed, the pedaling should not be stepped on when thepouring pressure is not up to the specified compressive strength.
(7) Brick round wells are required to checkthe diameter of the gravel. When closing the mouth, if the four sides are closed,the intake should not exceed 75px. If the three sides are collected, the intakeshould not exceed 125px.
(8) When brick inspection wells, the innerwall of the wellbore shall be jointed with the original slurry, and the innerwall surface of the well shall be laminated, and the uppermost layer of bricksand bricks below the cover.
(9) The manhole cover needs to be qualifiedbefore being poured, and the cast-in-place concrete construction must strictlycomply with the requirements of conventional concrete pouring and curing, so asto ensure that there is no exposed ribs, honeycomb and pockmarks afterdemoulding, leaving the test block for strength test. After completion of thewell chamber, timely remove the accumulated sludge, mortar, garbage and othermaterials in the well.
(10) When the top surface of the cover ison the road surface, the elevation of the top surface of the cover and theelevation of the road surface should be the same, the error should not exceed25mm. When it is non-road, the wellhead is slightly higher than the ground, andthe slope is 0.02.