Criterion of differential settlement in subgrade is useful for keeping road in a good serving condition. The theory of traditional materials strength and their technologic economy are applied to analyze the additional...Criterion of differential settlement in subgrade is useful for keeping road in a good serving condition. The theory of traditional materials strength and their technologic economy are applied to analyze the additional bend stress of the pavement structure, the equivalent beam of elastic foundation and influence on the pavement structure of an uneven settlement. The allowable settling ratio of pavement index （ △i ） is got and is used to appraise the uneven settlement standard value in subgrade. The allowable settling ratio of pavement index is applied in an certain widening expressway project and △i ≤0.36 % is attained by the analyzing, calculating and adding a certain safe coefficient. This value was put into practice and is effective during the past two years.展开更多
This paper presents the logic relationship between rural settlement reconstruction and soil conservation in the Upper Yangtze River. Firstly, by introducing the concepts of ＂flow＂ and ＂intercepted flow＂, we probe ...This paper presents the logic relationship between rural settlement reconstruction and soil conservation in the Upper Yangtze River. Firstly, by introducing the concepts of ＂flow＂ and ＂intercepted flow＂, we probe into the dynamic mechanism on interaction between ecological and environmental system, and then point out that the ＂intercepting sites＂ are physical conditions for establishment of human settlements in mountains. Secondly, by using ecological theories, ＂flow＂, ＂source＂, and ＂sink＂, material cycle and energy flow in mountains have been discussed. Thirdly, according to dissipative structure theory and thermodynamic laws, a hypothesis has been proposed that ＂entropy flow＂ is a dynamic force for settlement evolution. Finally, it is argued that a project for soil conservation is set to control and utilize flows so rural settlements can be supported and farmers＇ life improved.展开更多
基金Sponsored by Project of Ning Xia Hui Autonormous Region Communications Department2005
文摘Criterion of differential settlement in subgrade is useful for keeping road in a good serving condition. The theory of traditional materials strength and their technologic economy are applied to analyze the additional bend stress of the pavement structure, the equivalent beam of elastic foundation and influence on the pavement structure of an uneven settlement. The allowable settling ratio of pavement index （ △i ） is got and is used to appraise the uneven settlement standard value in subgrade. The allowable settling ratio of pavement index is applied in an certain widening expressway project and △i ≤0.36 % is attained by the analyzing, calculating and adding a certain safe coefficient. This value was put into practice and is effective during the past two years.
基金the Key Social Research Project of Education Ministry (04JZD0010)
文摘This paper presents the logic relationship between rural settlement reconstruction and soil conservation in the Upper Yangtze River. Firstly, by introducing the concepts of ＂flow＂ and ＂intercepted flow＂, we probe into the dynamic mechanism on interaction between ecological and environmental system, and then point out that the ＂intercepting sites＂ are physical conditions for establishment of human settlements in mountains. Secondly, by using ecological theories, ＂flow＂, ＂source＂, and ＂sink＂, material cycle and energy flow in mountains have been discussed. Thirdly, according to dissipative structure theory and thermodynamic laws, a hypothesis has been proposed that ＂entropy flow＂ is a dynamic force for settlement evolution. Finally, it is argued that a project for soil conservation is set to control and utilize flows so rural settlements can be supported and farmers＇ life improved.
