Beijing Asuwei landfill HDPE geomembrane middle cover construction scheme, for all landfill mediumcoverage provides geomembrane laying and welding, to solve the medium term covering the process ofrainwater diversion and gas drainage. Tai'an Ruiheng geotechnical material limited company provide friendship.

The first presentation was : what is the geomembrane? High density polyethylene geomembrane ( HDPE geotechnical membrane ) is a new type of waterproof anti-corrosion materials, the use of high-quality high density polyethylene virgin resin, main component is 97.5% high density polyethylene, about 2.5% of thecarbon black, trace amounts of antioxidant and stabilizer, anti-aging material, ultraviolet absorbent, by the single, double, three layer co-extrusion technology blow made. Quality of products using the United StatesASTM testing standards, fully meet the requirements of the United States GRI-GM13 standard.

Landfill HDPE geomembrane seepage prevention construction scheme

The first chapter, the base level requirements

1 HDPE before laying geomembrane, in conjunction with the civil engineering side, build, design, the owner of the laying base to conduct a comprehensive inspection, comply with the design requirements, to meet the construction conditions, and handover inspection record before construction.

2 surface quality should meet the design requirements: pit bottom surface, slope and slopes, slope, slopeanchoring groove with surface intersection is processing, the silo wall concrete structure surface shall bestrictly meet the design requirements.

3 surface should be dry, compaction, smooth, no cracks, no cusp, no mud, no depression, vertical depth within the 25mm root, gravel, rubble, should be reinforced, glass cutting head. Its formation degrees shall be within the allowable range changes smoothly, uniform slope, slope consensus.

4 the base at yin-yang angle image smooth transition, the root should be made of circular column.

The 5 substrate surface drying, moisture content should be below 15%.

The 6 substrate should be dense and homogeneous, soil basal stem density of not less than 1.4t/ ㎡.

7 in the construction, supervision, design units, the owners, the general contractor acceptance signature recognition can be carried out for paving geomembrane.

The second chapter, the climate requirement of construction

1 the temperature should be in commonly above five degrees C, low temperature geomembrane should benervous, high temperature geomembrane should relax.

In four the following 2 wind.

The 3 temperature is low, more than 4 winds and rain and snow weather in general should not construction.

4 in the wind weather, wind effects of geomembrane, to be welded HDPE geomembrane application ofsandbag pressure.

The third chapter, the HDPE geomembrane laying laying

1 HDPE geomembrane laying before the civil engineering a corresponding qualification and acceptance certificate.

2.HDPE tugongmo cut before, should measure the correlation dimension, then according to the actual cutting,the general should not be to press the cutting size, should one piece number, recorded in detail in specialform.

3 laying HDPE geomembrane should strive to weld the least, under the premise of guaranteeing quality, as far as possible to save raw material. It is also easy to ensure quality.

4 membrane and membrane joints between lap width not less than 10cm, usually make welds arrangement direction parallel to the maximum slope, along the slope direction.

Normally in the corner and deformity of 5 lots, should be the length of the joint to reduce short. Except special requirement, the slope is greater than 1:6 slope away from the top of slope and the stress concentration area within 1.5 meters, as far as possible without weld.

6.HDPE geomembrane laying, should avoid artificial fold, when the temperature is low, should be taut, paving.

7.HDPE geomembrane laying is completed, should be minimized in the membrane surface running, move tool, that can HDPE impervious membrane damage caused by objects, all should not be placed in the filmcarry on film or on foot, so as to avoid accidental injury of membrane.

The fourth chapter, geomembrane welding

1 hot wedge welder welding process is divided into: pressure regulating preset temperature set speed weldjoint inspection device for membrane into the engine starting motor pressure welding.

2 joints must be free from oil, dust, HDPE geomembrane overlapping section surface should not be clampedsediment and other debris, when there is debris must be cleaned before welding.

The 3 day began at the site welding, must try to welding a 0.9mm ×0.3mm sample, lap width not less than10cm, and the tensile machine scene peel and shear test, specimen after passing, can then adjust the speed,pressure, temperature is welding. The specimen on the need to indicate the date and time, the environment temperature. Thermal cut in welding, should pay attention on welding operation, according to the actual condition of velocity and temperature adjustment.

4 weld appearance, neat, no sliding welding, jump phenomenon.

5 in the event of geomembrane length is insufficient, need to splice, should first the transverse weld welding,welded longitudinal seam, transverse weld is greater than 50cm should be T fonts,

6 adjacent geomembrane seam should be staggered joint lap, membrane block nodes formed, should be Tfonts, minimize the cross, longitudinal mode to weld point application of extrusion welding strengthening.

The 7 film extrusion die welding to fold, laying HDPE geomembrane, according to local temperature variationamplitude and HDPE geotechnical membrane performance requirements, set aside the stretching deformationcaused by temperature changes.

8 when the portable welding machine temperature control the welding temperature is below 200 ℃, use a clean cloth or cotton dust and welding, when necessary, to polish, do not use hand rub.