tailieunhanh - Evapotranspiration covers for landfills and waste sites - Chapter 11

Chương này trình bày phương pháp và các thành phần xây dựng là duy nhất để đó (ET) thoát hơi nước bao gồm xây dựng bãi rác. Công nghệ liên bang và Hội đồng điều tiết (ITRC 2003) Trình bày bìa-xây dựng bãi rác thay thế hướng dẫn bao gồm; Một số Trong số đó làm việc và IS có liên quan để xây dựng bao gồm bãi rác. | 11 Construction This chapter presents construction methods and components that are unique to evapotranspiration ET landfill cover construction. The Interstate Technology and Regulatory Council ITRC 2003 presented cover-construction guidance for alternative landfill covers some of that work is pertinent to ET landfill cover construction. SOIL It is relatively easy to modify soils during cover construction some modifications are unintended and some of them may degrade the quality of the soil. It is also easy to add major plant nutrients nitrogen phosphorus and potassium to the soil placed in the ET cover and to adjust low soil pH. Soil density may be controlled within an optimum range during construction. However modification of properties such as high pH excess sodium or very high total soil salt may be impractical. Soil modification to improve its quality costs relatively little when compared to the total construction cost but it has the potential to improve performance lengthen life of the cover and to reduce long-term maintenance costs. Chapter 5 contains a discussion of soil properties that are important to ET landfill covers. The engineer should identify and specify soil properties before construction begins and closely monitor soil quality during construction because some soil properties are difficult and expensive to modify after construction is complete. Table lists important soil properties and Table lists test methods for soil properties that are important to ET landfill cover soils. Soil pH An effective means of correcting acid soils is to mix lime into each lift during placement. Standard methods are available to determine the lime requirement Sims 1996 . If the proposed borrow area supports robust plant growth the pH of the soil is probably adequate however it should be tested for pH level. Where soil pH is too high for native plants it is necessary to seek an alternate soil source because reducing soil pH is normally impractical.