外蒙奥尤陶勒盖OT项目废物处理中心填埋场防渗层渗漏破损探测的应用

本文通过对目前填埋场防渗系统的调查了解,分析了填埋场防渗系统渗漏检测的必要性,以外蒙奥尤陶勒盖OT项目废物处理中心填埋场防渗层渗漏破损探测检测为实例,介绍了电法检测方法对HDPE土工膜的完整性进行了检测,通过检测得出结论,该填埋场的防渗系统施工达到了良好标准。并展望了防渗系统渗漏检测的应用前景和社会效益。     

HDPE土工膜温度应力的试验研究

为了评价垃圾填埋场防渗系统中HDPE土工膜的温度应力,对短纤维无纺布和HDPE土工膜组成的防渗系统进行了模拟试验.试验结果表明,HDPE土工膜的温度应力随环境温度的变化而变化,当环境温度下降时将导致HDPE土工膜收缩产生温度应力.同时利用温度与HDPE土工膜弹性模量的关系对温度应力进行分析,计算结果与实测结果比较接近.     

土工膜在溧阳抽水蓄能工程中的应用

溧阳抽水蓄能电站上水库地质条件复杂,库盆防渗体系由于库底填渣厚度变化大,不均匀沉降较大,设计选定防渗材料适应不均匀变形能力强的HDPE土工膜作为上水库库底防渗体系;在减少渗漏损失的同时,可以降低工程施工难度。主要介绍了土工膜防渗方案的设计及应用,包括防渗层材料的选择及设计、土工膜周边连接设计、土工膜施工工艺等。     

HDPE土工膜柔性垂直防渗墙在污染治理项目中的应用

介绍了HDPE土工膜柔性垂直防渗墙的防渗原理与特点,结合四川江油某垃圾填埋场封场和云南某矿渣堆场污染治理的工程案例,重点阐述了HDPE土工膜柔性垂直防渗墙的应用优势、施工工艺流程和施工要点,指出需严格管控HDPE土工膜柔性垂直防渗墙产品系统和施工技术质量,从而保证防渗效果。     

热带地区城市垃圾填埋场防渗施工技术

以斯里兰卡科伦坡城市固体废弃物处理工程为依托,对垃圾填埋场防渗技术进行研究,并对膨润土垫和HDPE土工膜施工技术、施工存在的问题及控制要点进行阐述。工程应用表明,膨润土垫+HDPE土工膜+压实防渗黏土的复合防渗衬垫系统防渗效果良好。     

HDPE土工膜端部张拉力的大规模实测数据分析

 垃圾填埋场边土工膜主要受到温度应力和垃圾压缩引起的张拉力的作用，为评价垃圾填埋场防渗系统中高密度聚乙烯(HDPE)土工膜的温度应力和垃圾填埋压缩引起的端部张拉力，以短纤维无纺布、HDPE土工膜组成防渗系统，进行大规模现场试验。试验结果表明：伴随环境温度的下降，HDPE土工膜中产生温度应力，当填埋高度较小时作用在HDPE土工膜端部的张拉力主要为温度应力；随着填埋高度的增加，压缩引起的HDPE土工膜端部张拉力增大。用有限元算法对压缩引起的端部张拉力进行分析，并采用温度与HDPE土工膜张拉力的关系对温度应力进行分析。计算结果与实测结果的对比情况表明，考虑填埋压缩引起的张拉力的应力松弛后计算结果更加接近实测结果。     

HDPE土工膜在填埋场中的应用技术与施工工艺

本文分析了HDPE,即高密度级乙烯土工膜的特征,通过对比分析,结合国家对于填埋场中防渗材料的相关规定,深入介绍了HDPE土工膜在填埋场中的应用技术相关的施工注意事项。其中,HDPE 土工膜的选材及施工技术质量控制,对于保证防渗层使用可靠性具有极大的意义。     

城市生活垃圾卫生填埋场的HDPE土工膜防渗技术

HDPE土工膜已成为城市生活垃圾卫生填埋场防渗系统的首选材料，介绍了HDPE土工膜的基本特性以及在垃圾填埋场应用中的设计和施工要点。     

HDPE膜在垃圾处理中心的施工技术

随着我国城市建筑垃圾产生的快速增长,HDPE土工膜防渗层在垃圾处理中心的应用取得了较大的突破。但由于各方面原因,HDPE土工膜防渗层在实施过程中出现了系列问题,使该施工技术很难广泛推广。以杭州地区某代表性垃圾处理中心工程为例,对HDPE土工膜的铺设、焊接、检测和修补等施工技术进行了深入研究,确定了HDPE土工膜施工方案,为类似工程提供借鉴作用。     

运用QC方法提高HDPE土工膜焊接合格率

HDPE土工膜以其防渗性能好、性价比高等优点,在填埋场建设中起到重要作用,其焊接质量直接影响到填埋场的防渗系统水平乃至工程整体的质量。为提高HDPE土工膜焊接的施工质量,运用QC方法对土工膜施工过程展开研究,以QC小组的研究形式找到一种有效的方法。该方法提高了焊接质量合格率,为类似填埋场建筑施工质量提供了参考。     

Assessment of HDPE geomembrane performance in a municipal waste landfill double liner system after eight years of service

In the late 1970s and early 1980s, environmental regulations were upgraded in a general national movement to effect secure management of our municipal and residual solid wastes. The new regulations required varying combinations of natural and/or synthetic barrier and drainage layers to prevent the unrestricted release of contaminants.

The acceptable barrier materials included synthetic flexible membrane liners (FMLs) of various types. One of those most commonly used has been high-density polyethylene (HDPE) geomembrane. HDPE has been selected because of its good chemical resistance characteristics, among others. Background compatibility testing has shown the HDPE geomembrane to be extremely resistant to the leachates that are generated by municipal and residual solid waste landfills. The background testing for design has generally been based on relatively short-term tests that are conducted under extreme conditions to ‘forecast’ service life.

Recently, a municipal solid waste landfill double liner system that was constructed in 1988 was exhumed. The HDPE geomembranes of this liner system had been exposed to varying degrees of leachate since 1989. Samples of the HDPE were extracted from the in-place liner system and were laboratory-tested for physical, mechanical and endurance properties. The selected suite of tests duplicated the test protocol conducted in 1988 as part of the liner system construction quality assurance (CQA) program.

The results of this testing show that the HDPE properties are still within the range of data generated by the original testing in 1988. No degradation in properties was indicated by this testing program. The HDPE had been exposed to the leachate, methane, and static and dynamic stresses for approximately 8 years. The results of this test program support the design selection of HDPE as the synthetic barrier component of this landfill liner system.     

垃圾填埋场土工合成材料界面摩擦特性的拉拔试验研究

土工合成材料与填料的界面特性是决定垃圾填埋场中衬垫系统与土工合成材料受力特性的重要因素。选择3种不同种类的土工合成材料,用砂土和黏土为填料,通过拉拔试验研究土工合成材料的界面特性。试验结果表明:界面的峰值剪切强度与峰值位移随着法向应力的增加而增加;土工合成材料与黏土之间的摩擦角较大;填料为砂土时,无纺布与填料间的摩擦角最大,EPDM次之,HDPE最小;当HDPE上下都铺无纺布时,界面的摩擦系数最小。     

Geomembrane-clay composite liners

A successful 1·22 m wide HDPE/Bentonite composite liner widely used in the waterproofing industry is now available as a 5·33 m wide geomembrane. Properties and potential applications are discussed.     

The performance of concrete protection liners in mine SX/EW mixers and settlers: The need for chemical resistance testing

In an attempt to save costs many mines have replaced stainless steel solvent extraction/electrowinning (SX/EW) mixer/settler tanks with concrete basins lined with anchored concrete protection liner (CPL) on floor and walls, or CPL on walls and loose liner on the floor. The latter system, made with high density polyethylene (HDPE), was specified for a copper mine with novel aqueous and organic process solutions at higher than normal temperatures, approximately 55 °C. The solutions included sulfuric acid and aromatic hydrocarbons. The HDPE geomembrane manufacturer urged the design engineer to perform a chemical resistance test, a ∼$15,000 quality assurance investment. The engineer declined because he claimed prior success with this system. The liner failed. The forensic investigation is described.     

Application of HDPE at a sewage treatment plant

A pair of aeration lagoons at a wastewater treatment facility were lined with 0.75-mm HDPE geomembrane in 1993. The ponds were placed in an area that previously contained an unlined sewage stabilization pond. This paper discusses activity at the east lagoon only. Prior to liner installation, a gas vent system was added in the design in the event that gases formed under the liner. That system employed approximately 30-cm-wide strips of geotextile/geonet geocomposite placed on 30-m centers in a grid pattern. Gas vents were cut in the liner around the top perimeter of the pond at 15-m centers. Thorough construction quality assurance practices were employed to insure that the geomembrane and seams were of a high quality. Seven months after installation, gas bubbles began to form under the liner, and large bubbles resulted. The bubbles were pierced to remove the gas. At that time, the lagoon was taken out of service and drained for inspection. Crescent moon-shaped cuts (about 300 mm in size) were then found at the location of some of the baffle curtain anchors. This damage was repaired in conjunction with the holes created by venting the gas bubbles. The lagoon was then partially filled, and more bubbles were formed under the liner. Analysis of the gas resulted in the opinion that it was the result of anaerobic digestion of organic matter under the liner. Also found were holes approximately 60 mm in size that were grouped in random locations throughout the lagoon. These holes were in pairs and spaced 3 to > 30 mm apart. The source of those holes remains unknown. In retrospect, a gas vent system capable of removing gases at a greater rate than it was generated from beneath the liner was required. It is suggested that when a previously existing pond is to be lined, extensive testing for organic matter be performed on subgrade material. Such testing is not currently well defined and should occur prior to design. Other investigations may include hydrological surveys that include several years' data on underlying water level activity. Also, a thicker geomembrane may have had enough resistance to mechanical damage to prevent the formation of the crescent moon and smaller holes.     

Oberflächenabdichtungen aus PE‐HD‐Dichtungsbahnen für Altdeponien

Surface lining with HDPE geomembranes of old municipal waste landfills. Until mid‐2005 approximately 250 old municipal waste landfills have to be closed, because they failed to meet the requirements according to the state of landfill engineering. After closure, a containment and remediation concept has to be put into action. At landfill sites with appropriate conditions (e.g. base liner and waste water collection system), one may try to stabilize the waste body by forcing up through water infiltration the anaerobic biochemical reaction within the waste body or by aerobic stabilization techniques. However, engineered capping systems are an indispensable tool in the containment strategy for waste disposal. Reliable, highly effective and long lasting liner systems can be installed even under the special conditions on the surface of old landfills. In particular, selected HDPE geomembranes are highly suited for these conditions. However, approval of geomembrane products for this application is essential, since geomembranes made of different HDPE resins as well as differently produced out of the same HDPE resin may extremely differ in their long‐term and installation properties.     

HDPE土工膜用于水泥混凝土灌溉渠道修复施工

结合具体工程实例,阐述了决定实施HDPE土工膜焊接修复技术方案的主要因素,详细介绍了HDPE土工膜用于水泥混凝土灌溉渠道修复施工的工艺,以推广防渗土工膜在工程中的应用。     

水化状态对含针刺GCL复合衬里抗剪强度的影响分析

针刺GCL和HDPE土工膜(GM)在防渗工程中应用广泛,含多层界面的复合衬里整体抗剪强度是边坡稳定性分析的关键。介绍了含针刺GCL复合衬里的大单剪试验方法,并且对比分析了针刺GCL初始状态分别为干燥和完全水化两种情况下的复合衬里抗剪强度。结果表明,复合衬里的剪切破坏不会发生在干燥针刺GCL内部界面,而GCL干燥状态下的复合衬里单剪强度未必高于GCL完全水化状态下的复合衬里单剪强度。结合含GCL复合衬里的剪切破坏机理,阐述了针刺GCL的水化状态对复合衬里抗剪强度的影响。含GCL复合衬里在不同水化状态下的界面滑移稳定性都应引起工程人员的重视。     

Development of geomembrane strains in waste containment facility liners with waste settlement

The development of tensile strains in geomembrane liners due to loading and waste settlement in waste containment facilities is examined using a numerical model. Two different constitutive models are used to simulate the waste: (a) a modified Cam-Clay model and (b) a Mohr-Coulomb model. The numerical analyses indicate the role of the slope inclination on the maximum geomembrane liner strains for both short-term loading (immediately post closure) and long-term waste settlement. A geosynthetic reinforcement layer over the geomembrane liner is shown to reduce the maximum geomembrane liner strains, but the strain level of the geosynthetic reinforcement itself may become an engineering concern on steeper slopes (i.e., greater than 3H:1V) for cases and conditions examined in this paper. The paper considers some factors (e.g., slope inclination, use of a high stiffness geosynthetic over the geomembrane liner) and notes others (e.g., the designer selection of interface characteristics below and above the geomembrane, use of a slip layer above the geomembrane) that warrant consideration and further investigation to ensure good long-term performance of geomembrane liners in waste containment facilities.