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Engineering of Landfill Barrier Systems
Published in T. H. Christensen, R. Cossu, R. Stegmann, Landfilling of Waste: Barriers, 2020
After installation and control, geomembranes have to be mechanically protected. To this purpose sandy soil is often adopted with 20-30 cm thickness. As an alternative, particularly when a gravel drainage layer is installed above the liner, geotextile or geocomposite can be interposed between the granular and synthetic material (seeChapter 5.3).
Guidelines on the use of liners in highway construction
Published in R. M. Koerner, E. Gartung, H. Zanzinger, Geosynthetic Clay Liners, 2020
The minimum thickness of the geomembranes is 1.0 mm. A greater thickness may be necessary to ensure that a tension-proof overlapping seam can be made. The most suitable material for the geomembrane is high density polyethylene (HDPE).
Construction Quality Assurance/Quality Control for Landfills E. Daniel and Robert M. Koerner
Published in Robert E. Landreth, Paul A. Rebers, Municipal Solid Wastes, 2020
David E. Daniel, Robert M. Koerner
Peel testing of specimens taken from field fabricated geomembrane seams represent a quality control type of index test. Such tests are not meant to simulate in situ performance but are very important indicators of the overall quality of the seam. The recommended peel tests for HDPE, PVC, CSPE-R, and EIA-R seams, along with the unseamed sheet material in tension are given in Table 13.8. The VLDPE data was included in a way so as to parallel the HDPE testing
Strength and structural variations in dredger fill subjected to vacuum dynamic consolidation
Published in Marine Georesources & Geotechnology, 2021
You Zhou, Hongtao Fu, Tian Jin, Mingfeng Li, Junfeng Ni
The test buckets used herein were made of polymethyl methacrylate and were designed with an inner diameter of 300 mm and a depth of 500 mm, as shown in Figure 3. The PVDs, vacuum pump, and vacuum pipe were the primary components of the VP apparatus. A PVD was inserted into each test bucket, and the system requirements in terms of the ratio of the PVD influence diameter to the PVD equivalent diameter were verified. The vacuum pressure of the PVDs was measured using vacuum gauges at one end of the vacuum pipe. A geomembrane was used as the air-sealing layer to isolate the samples from the atmosphere, and a single geotextile layer was placed above and below the geomembrane for protection. The vertical deformation of the samples was measured using a customized settlement plate. During tamping, the settlement plate was removed, and a sand cushion was laid instead. After tamping, the sand cushion was removed, and the vertical deformation was observed. The apparatus used for the laboratory vacuum dynamic consolidation tests is shown in Figure 3a, and the basic experimental setup is shown in Figure 3b. The apparatus consists of a test bucket, a positioning guide rod, a hammer, and the sand cushion. The positioning guide rod was used to determine the accuracy of the tamping points and ensure that no sideslip occurred during the falling process while tamping. A 100-mm thick sand cushion was placed on the surface of the geomembranes as a buffer layer.
Improvement of dredger fill by stepped vacuum preloading combined with stepped voltage electro-osmosis
Published in Marine Georesources & Geotechnology, 2021
Feiyu Liu, Zhe Li, Guohui Yuan, Xiuqing Hu, Dikang Zhang, Yunguo Du, Changfei Gou
The VP system consisted of a vacuum pump, a high vacuum trimming valve, a water-air separation bottle, two layers of sealing membrane, a layer of geotextile, and an integrated PVD. A vacuum pump with a power output of 3.88 kW and a vacuum pressure limit of 98 kPa was used. The high vacuum trimming valve was adjusted to produce different air leakage, thereby changing the vacuum pressure in the test system; simultaneously, the vacuum gauge was read to control the vacuum pressure as the target value. The water-air separation bottle was used to store the water discharged during the test. Two layers of geomembrane were used to cover and seal the soil, and a layer of geotextile was used to cover the soil and prevent rupturing of the geomembrane. An integrated PVD was used as a drainage channel through which water in the soil could be discharged, which increased the tensile strength and discharge capacity by 19 and 38%, respectively, compared to conventional PVDs (Liu and Chu 2009); the detailed properties of the integrated PVD are outlined in Table 2, and the length of the integrated PVD was 450 mm.
Necessity of water treatment to meet lake water quality goals in Chitgar Lake
Published in Lake and Reservoir Management, 2021
Javad Bayat, Seyed Hossein Hashemi, Mir Fazel Nikzad, Seyed Mohammad Reza Talakesh
Chitgar Lake is located in northwest Tehran at the heart of municipal district 22, and is surrounded by high-rise residential and commercial buildings, 2 highways, and a planted forest. It is a shallow lake (3.5 m average) with an area of 132 ha and maximum depth of 9.5 m in the southern overflow area with 3 islands (gray shapes in Figure 1). The lake bed is sealed by geomembrane and geotextile layers to prevent water loss. The volume of the lake is 6,900,000 m3 at an elevation of 1267.5 m above sea level, which diminishes to about 5,200,000 m3 at the end of the dry season (autumn). The Kan River provides freshwater for the lake during the winter through diversion. Therefore, the water depth fluctuates on a yearly basis, because of evaporation and filling mechanisms. All information regarding the lake filling system is presented in Emam et al. (2016).