考虑水稳定性影响的膨胀土路基填料承载比特性

根据试验规范进行室内承载比（CBR）试验,研究压实度和膨胀率对其承载比（CBR）值的影响规律,分析膨胀土以及石灰改良膨胀土的CBR值随压实度和膨胀势变化的基本规律,研究认为,CBR值随压实度的减小而减小,随膨胀势的减小而增大。石灰改良膨胀土用于路堤填筑时,压实度略低的标准控制,有利于路堤的长期稳定。     

高液限土最佳掺砂比的确定

为确定最佳掺砂比,按细颗粒含量、液限、素土的CBR值(加州承载比)分别对高液限土进行分类,按掺砂改良后CBR值为6分别确定不同分类高液限土最佳掺砂比的范围,再综合考虑这3种要素确定最佳掺砂量.试验结果表明:细颗粒含量对CBR值的影响大于液限和黏粉比;黏粉比越小,CBR值越大;广东云罗高速沿线高液限土的最佳掺砂比约为20%;不同性质高液限土应采取弃方、掺砂改良和直接填筑3种不同的处理方法.     

Coastal Ecosystems and Agricultural Land Use: New Challenges on California's Central Coast

This article uses the Central Coast region of California as a case study to examine the challenges of protecting coastal ecosystems near areas of intensive agricultural production. Coastal water quality and biodiversity are greatly impacted by regional land use. Agricultural land use can have significant impacts on water quality through erosion and the runoff of agricultural chemicals. While the Central Coast region of California is a center for intensive agricultural production, it is also home to the largest marine sanctuary in the United States. This combination has resulted in intensive efforts from government agencies and conservation organizations to reduce pollution associated with agriculture. Efforts have focused on education and incentives, but are recently facing increasing challenges stemming from new standards created by the produce industry in response to food safety concerns. Personal interviews with crop growers were used to explore these challenges and to better understand the range of possible environmental impacts resulting from new food safety standards. Results indicate that substantial management changes are taking place that are likely to impact regional water quality and wildlife. This case study also explores the role of policy networks in shaping management decisions and illustrates how certain approaches to addressing agricultural pollution may be vulnerable to external policy changes.     

Inclusionary housing in the California coastal zone

Abstract

This article evaluates the performance of the California Coastal Commission's inclusionary housing program by examining: (1) the scope of the housing regulations, (2) initial permit decisions on residential projects, (3) the disposition of these permits overtime, and (4) the composition of completed projects and a best‐case projection of possible project completions. Using a case study of Southern California, factors affecting program success are discussed, including the effects of the various regulations, the availability of project subsidies, local government permit policies, and housing market fluctuations. The authors conclude that such state regulatory programs cannot be expected to succeed in urbanized coastal areas without incentives for developers and augmented state agency authority, superseding local land use controls.