tailieunhanh - Evapotranspiration covers for landfills and waste sites - Chapter 13

Thiết kế và quy định quy tắc Nội quy, quy chế quy định phần lớn các thiết kế bao gồm thông thường-rào cản. Quy tắc như vậy hạn chế và ứng dụng của họ cho phép tự do giới hạn cho các kỹ sư thiết kế để tạo ra bao gồm bãi rác mới và tốt hơn. May mắn thay, Quy chế cho phép các thiết kế aussi thay thế, tuy nhiên, tính năng quan trọng của Quy định nằm ngủ và không sử dụng cho nhiều năm. Hiện nay, MỘT SỐ điều tiết và kỹ sư Tích cực thúc đẩy. | 13 Miscellany and Summary This chapter contains topics that did not fit in other chapters sources for technical data and a closing summary statement. DESIGN AND PRESCRIPTIVE RULES Rules and regulations prescribe important parts of conventional-barrier cover design. Such restrictive rules and their application allow limited freedom for the design engineer to create new and better landfill covers. Fortunately the regulations also allow alternate designs however this important feature of regulations lay dormant and unused for many years. At present some regulators and engineers actively promote and examine alternative designs. Thus the situation is improving. ALLOWABLE LEAKAGE When the evapotranspiration ET landfill cover was first introduced to regulatory bodies they rejected the concept because it does not follow the prescriptive rules and regulations and also because of the widely held perception that conventional covers are impermeable. The myth of impermeability was part of the accepted notion that conventional-barrier covers are adequate and provide a suitable presumptive remedy for landfill remediation. The performance measurements for conventional-barrier landfill covers cited in Chapter 3 were the result of relatively short field tests. None of the published measurements exceeded two decades in duration most measurement periods were less than 5 years in length. In some instances the percolation rate through the cover was increasing at the end of the short test. The duration of these tests is short when compared to an expected need for a cover that extends to multiple decades or centuries. In addition future events are likely to increase the leakage through barrier covers for example waste settlement creates major stresses on the cover. Conventional-barrier landfill covers oppose natural forces this is a major reason to expect them to leak more not less in the future. In spite of the strong evidence that they leak correctly built barrier covers have