Liu Senlin, in the opinion of sustainable development, thinks that the current forming of historical materialism must get rid of those concepts disagreeable to the sustainable development at present. Liu Huaiyu sets f...Liu Senlin, in the opinion of sustainable development, thinks that the current forming of historical materialism must get rid of those concepts disagreeable to the sustainable development at present. Liu Huaiyu sets forth the " space theory" that plays a role in the analysis of the relationship between the capitalist development and space planning. Yu Jianxing points out that the Marxist theory of State has a tendency of renascence. Wu Xiangdong stresses the system and value. Yang Haifeng thinks historical materialism must face the problems that consumption society has caused.展开更多
国土空间规划是落实主体功能区战略、绘制未来“美丽国土一张蓝图”的重要抓手,资源环境承载能力和国土空间开发适宜性评价是国土空间规划编制的前提和基础.以贵州省黔西南布依族苗族自治州义龙新区为研究对象,围绕生态保护、农业生产...国土空间规划是落实主体功能区战略、绘制未来“美丽国土一张蓝图”的重要抓手,资源环境承载能力和国土空间开发适宜性评价是国土空间规划编制的前提和基础.以贵州省黔西南布依族苗族自治州义龙新区为研究对象,围绕生态保护、农业生产、城镇建设功能特征,以定量方法为主、定性方法为辅,依次开展了资源环境要素单项评价、资源环境承载能力集成评价、国土空间开发适宜性评价,并与现状土地利用进行对比,识别其国土空间开发问题和潜力.结果表明:①义龙新区生态保护极重要区面积占比为36.93%,农业生产适宜区面积占比为24.84%,城镇建设适宜区面积占比为25.08%,三者可分别作为重点生态功能区、农产品主产区、城市化发展区.②生态保护极重要区中基本农田面积为23.60 km 2、一般农用地面积为15.21 km 2,农业生产不适宜区中基本农田面积为72.17 km 2、一般农用地面积为27.63 km 2,地块功能指向重叠性较大,建议结合城市发展意向,明确不同区域功能指向的侧重.③后备耕地面积为131.87 km 2,后备建设用地面积为114.85 km 2,与实地核查结果相符.研究显示,构建的喀斯特地区“双评价”方法体系可以很好地应用于区域国土空间规划,实现了格网单元地域功能优化分区.展开更多
The addition of basement beneath existing building changes the underpinning pile from fully embedded to partially embedded,and thus influences the mechanical properties of pile.In the past,scholars paid attention to t...The addition of basement beneath existing building changes the underpinning pile from fully embedded to partially embedded,and thus influences the mechanical properties of pile.In the past,scholars paid attention to the change in the bearing capacity of pile but neglected the difference of dynamic characteristics before and after construction,and potential changes in stress history of remaining soil are also ignored.In this work,a calculation model is built to investigate the influence of excavation on dynamic impedance of underpinning pile considering the effect of stress history.The soil is simulated by the dynamic Winkler foundation,which is characterized by springs and dashpots.Properties of remaining soil after excavation are updated to consider the effect of stress history through modifying the initial shear modulus and related parameters.The dynamic impedance of pile after excavation is obtained based on the transfer matrix method.The parameter study is carried out to evaluate the dynamic impedance with various excavation depths,considering or ignoring stress history effect,and various element lengths.The results show that shallow soil plays an important role to dynamic impedance,and overestimated dynamic impedance is obtained if not considering the stress history effect.展开更多
文摘Liu Senlin, in the opinion of sustainable development, thinks that the current forming of historical materialism must get rid of those concepts disagreeable to the sustainable development at present. Liu Huaiyu sets forth the " space theory" that plays a role in the analysis of the relationship between the capitalist development and space planning. Yu Jianxing points out that the Marxist theory of State has a tendency of renascence. Wu Xiangdong stresses the system and value. Yang Haifeng thinks historical materialism must face the problems that consumption society has caused.
文摘国土空间规划是落实主体功能区战略、绘制未来“美丽国土一张蓝图”的重要抓手,资源环境承载能力和国土空间开发适宜性评价是国土空间规划编制的前提和基础.以贵州省黔西南布依族苗族自治州义龙新区为研究对象,围绕生态保护、农业生产、城镇建设功能特征,以定量方法为主、定性方法为辅,依次开展了资源环境要素单项评价、资源环境承载能力集成评价、国土空间开发适宜性评价,并与现状土地利用进行对比,识别其国土空间开发问题和潜力.结果表明:①义龙新区生态保护极重要区面积占比为36.93%,农业生产适宜区面积占比为24.84%,城镇建设适宜区面积占比为25.08%,三者可分别作为重点生态功能区、农产品主产区、城市化发展区.②生态保护极重要区中基本农田面积为23.60 km 2、一般农用地面积为15.21 km 2,农业生产不适宜区中基本农田面积为72.17 km 2、一般农用地面积为27.63 km 2,地块功能指向重叠性较大,建议结合城市发展意向,明确不同区域功能指向的侧重.③后备耕地面积为131.87 km 2,后备建设用地面积为114.85 km 2,与实地核查结果相符.研究显示,构建的喀斯特地区“双评价”方法体系可以很好地应用于区域国土空间规划,实现了格网单元地域功能优化分区.
基金Projects(51878487,41672266)supported by the National Natural Science Foundation of China。
文摘The addition of basement beneath existing building changes the underpinning pile from fully embedded to partially embedded,and thus influences the mechanical properties of pile.In the past,scholars paid attention to the change in the bearing capacity of pile but neglected the difference of dynamic characteristics before and after construction,and potential changes in stress history of remaining soil are also ignored.In this work,a calculation model is built to investigate the influence of excavation on dynamic impedance of underpinning pile considering the effect of stress history.The soil is simulated by the dynamic Winkler foundation,which is characterized by springs and dashpots.Properties of remaining soil after excavation are updated to consider the effect of stress history through modifying the initial shear modulus and related parameters.The dynamic impedance of pile after excavation is obtained based on the transfer matrix method.The parameter study is carried out to evaluate the dynamic impedance with various excavation depths,considering or ignoring stress history effect,and various element lengths.The results show that shallow soil plays an important role to dynamic impedance,and overestimated dynamic impedance is obtained if not considering the stress history effect.
