北京阿蘇衛(wèi)垃圾填埋場HDPE土工膜中期覆蓋施工方案
北京阿蘇衛(wèi)垃圾填埋場HDPE土工膜中期覆蓋施工方案，為所有垃圾填埋場中期覆蓋提供土工膜的鋪設與焊接，解決中期覆蓋過程中雨水分流及沼氣導排。泰安市瑞恒土工材料有限公司友情提供。
首先介紹的是：什么是土工膜？高密度聚乙烯土工膜(HDPE土工膜)是一種新型特種防滲防腐材料,采用的高密度聚乙烯原生樹脂，主要成分為97.5％ 的高密度聚乙烯，約2.5％的碳黑、微量的抗氧劑和熱穩(wěn)定劑，抗老化材料、紫外線吸收劑，經(jīng)單層、雙層、三層共擠技術(shù)吹塑制成。產(chǎn)品質(zhì)量采用美國ASTM測試標準，完全達到美國GRI-GM13標準要求。
垃圾填埋場HDPE土工膜防滲施工方案
章、基面要求
1.鋪設HDPE土工膜前，應會同土建方、建立、設計、業(yè)主對鋪設基底進行檢查，符合設計要求、滿足施工條件，并作交接檢記錄后方可施工。
2.基面質(zhì)量應符合設計要求：基坑底面、坡面及其坡比、邊坡上錨固槽、坡面與義面交接處處理，倉壁混凝土結(jié)構(gòu)基面均應嚴格達到設計要求。
3.基面應干燥、壓實、平整、無裂痕、無明顯尖突、無泥濘、無凹陷，垂直深度25mm內(nèi)部應有樹根、瓦礫、石子、鋼筋頭、玻璃屑。其平整度應在允許的范圍內(nèi)平緩變化，坡度均勻，坡度一致。
4.基面上的陰陽角處影圓滑過渡，柱根部應做成圓弧狀。
5.基底表面干燥，含水率宜在15%以下。
6.基底應密實均勻，土質(zhì)基底的干密度不得小于1.4t/㎡。
7.在土建、監(jiān)理、設計單位、業(yè)主、總承包人驗收簽字認可后便可進行鋪土工膜施工。
第二章、施工的氣候要求
1.氣溫一般應在五攝氏度以上，低溫時土工膜應緊張些，高溫時土工膜應放松些。
2.風力在四級以下。
3.氣溫過低時，4級以上大風及雨雪天氣一般不應施工。
4.在風天氣，風力影響土工膜施工時，待焊的HDPE土工膜應用砂袋壓牢。
第三章、HDPE土工膜鋪的鋪設
1.鋪設HDPE土工膜前應由土建工程相應的合格驗收證明文件。
2.HDPE土工膜裁切之前，應該準確丈量其相關(guān)尺寸，然后按實際裁切，一般不宜按圖示尺寸裁切，應逐片編號，詳細記錄在表格上。
3.鋪設HDPE土工膜時應力求焊縫少，在保證質(zhì)量的前提下，盡量節(jié)約原材料。同時也容易保證質(zhì)量。
4.膜與膜之間接縫的搭接寬度一般不小于10cm，通常就使焊縫排列方向平行于坡度，即沿坡度方向排列。
5.通常在拐角及畸形地段，應是接縫長度盡量減短。除特殊要求外，在坡度大于1：6的斜坡上距頂坡或應力集中區(qū)域1.5米范圍內(nèi)，盡量不設焊縫。
6.HDPE土工膜在鋪設中，應避免產(chǎn)生人為褶皺，溫度較低時，應盡量拉緊，鋪平。
7.HDPE土工膜鋪設完成后，應盡量減少在膜面上行走、搬動工具等，凡能對HDPE防滲膜造成危害的物件，均不應放在膜上或攜帶在膜上行走，以免對膜造成意外損傷。
第四章、HDPE土工膜的焊接
1.熱鍥焊機焊接工序分為：調(diào)節(jié)壓力設定溫度設定速度焊縫搭接檢查裝膜入機啟動馬達加壓焊接。
2.接縫處不得有油污、灰塵，HDPE土工膜的搭接段面不應夾有泥沙等雜物，當有雜物時必須在焊接前清理干凈。
3.每天焊接開始時，必須在現(xiàn)場先試焊一條0.9mm×0.3mm的試樣,搭接寬度不小于10cm,并用拉力機現(xiàn)場進行剝離和剪切試驗,試樣合格后,便可用當時調(diào)整好的速度、壓力、溫度進行正是焊接。試樣上需標明日期、時刻、環(huán)境溫度。熱鍥焊機在焊接過程中，需隨時注意焊機的運行情況，要根據(jù)現(xiàn)場的實際情況對速度和溫度進行微調(diào)。
4.焊縫要求整齊、美觀、不得有滑焊、跳走現(xiàn)象。
5.在遇上土工膜長度不夠時，需要長向拼接，應先把橫向焊縫焊好，再焊縱縫，橫向焊縫相距大于50cm應成T字型，
6.相鄰土工膜焊縫應盡量錯縫搭接，膜塊間形成的結(jié)點，應為T字型，盡量減少十字型，縱模向焊縫交點處應用擠壓焊機加強。
7.焊膜時不許壓出死折，鋪設HDPE土工膜時，根據(jù)當?shù)貧鉁刈兓群虷DPE土工膜性能要求，預留出溫度變化引起的伸縮變形量。
8.當手提焊機的溫度控制所指示的焊機溫度低于200℃時，要用干凈的布或棉紗撣掉再焊，必要時應重新打磨，切忌用手擦試。
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.