顾及城市规划、建设、管理等政府部门需求,结合城市空间基础数据实际情况,基于三维GIS(geographic information system)开发了地上地下一体化三维系统。研究了多模态时空数据集成管理、地下三维管线自动建模、工程地质建模分析、城市空...顾及城市规划、建设、管理等政府部门需求,结合城市空间基础数据实际情况,基于三维GIS(geographic information system)开发了地上地下一体化三维系统。研究了多模态时空数据集成管理、地下三维管线自动建模、工程地质建模分析、城市空间产权管理关键技术和功能,为城市实景三维场景组织调度、地下空间可视化应用以及城市立体空间精细化管理提供决策支持。以成都市数据为例,验证了系统的可行性和有效性。展开更多
Adopting the quasi-three-dimensional （Quasi-3D） numerical method to optimize the anti-freeze design parameters of an underground pipeline usually involves heavy numerical calculations. Here, the fitting formulae bet...Adopting the quasi-three-dimensional （Quasi-3D） numerical method to optimize the anti-freeze design parameters of an underground pipeline usually involves heavy numerical calculations. Here, the fitting formulae between the safe con-veyance distance （SCD） of a water pipeline and six influencing factors are established based on the lowest water temper-ature （LWT） along the pipeline axis direction. With reference to the current widely used anti-freeze design approaches for underground pipelines in seasonally frozen areas, this paper first analyzes the feasibility of applying the maximum frozen penetration （MFP） instead of the mean annual ground surface temperature （MAGST） and soil water content （SWC） to calculate the SCD. The results show that the SCD depends on the buried depth if the MFP is fixed and the variation of the MAGST and SWC combination does not significantly change the SCD. A comprehensive formula for the SCD is estab-lished based on the relationships between the SCD and several primary influencing factors and the interaction among them. This formula involves five easy-to-access parameters： the MFP, buried depth, pipeline diameter, flow velocity, and inlet water temperature. A comparison between the analytical method and the numerical results based on the Quasi-3D method indicates that the two methods are in good agreement overall. The analytic method can be used to optimize the anti-freeze design parameters of underground water pipelines in seasonally frozen areas under the condition of a 1.5 safety coefficient.展开更多
文摘顾及城市规划、建设、管理等政府部门需求,结合城市空间基础数据实际情况,基于三维GIS(geographic information system)开发了地上地下一体化三维系统。研究了多模态时空数据集成管理、地下三维管线自动建模、工程地质建模分析、城市空间产权管理关键技术和功能,为城市实景三维场景组织调度、地下空间可视化应用以及城市立体空间精细化管理提供决策支持。以成都市数据为例,验证了系统的可行性和有效性。
基金financially supported by the National Basic Research Program of China (No. 2013CBA01803)the National Natural Science Foundation of China (No. 41101065)and the CAS "Equipment Development Project for Scientific Research" (No. YZ201523)
文摘Adopting the quasi-three-dimensional （Quasi-3D） numerical method to optimize the anti-freeze design parameters of an underground pipeline usually involves heavy numerical calculations. Here, the fitting formulae between the safe con-veyance distance （SCD） of a water pipeline and six influencing factors are established based on the lowest water temper-ature （LWT） along the pipeline axis direction. With reference to the current widely used anti-freeze design approaches for underground pipelines in seasonally frozen areas, this paper first analyzes the feasibility of applying the maximum frozen penetration （MFP） instead of the mean annual ground surface temperature （MAGST） and soil water content （SWC） to calculate the SCD. The results show that the SCD depends on the buried depth if the MFP is fixed and the variation of the MAGST and SWC combination does not significantly change the SCD. A comprehensive formula for the SCD is estab-lished based on the relationships between the SCD and several primary influencing factors and the interaction among them. This formula involves five easy-to-access parameters： the MFP, buried depth, pipeline diameter, flow velocity, and inlet water temperature. A comparison between the analytical method and the numerical results based on the Quasi-3D method indicates that the two methods are in good agreement overall. The analytic method can be used to optimize the anti-freeze design parameters of underground water pipelines in seasonally frozen areas under the condition of a 1.5 safety coefficient.
