简介:ThecholeraoutbreakinEastAfricaandPerumadeKenya,Tanzania,UgandaandPerusufferheavilynotonlyfromlostlives,butalsofromlostexportsandadropintourism.However,lessonsfromPeruandEastAfricaandtheyearsofstrugglebytheUnitedNationsanditspartners,havefinallystirredtheinternationalcommunitytoaction.WaterandsanitationemergedasakeydevelopmentissueattheWorldSummitonSustainableDevelopmentinJohannesburg,SouthAfricalastyear.WorldHabitatDaythisyearfocusedonWaterandSanitationforCities.Thiscouldbeadefiningmomentfornationalplanner,policy-makersandcityauthoritiestoreflectonthechallengeaheadandtodedicatethemselvesanewtoataskthatastatementbyworldleadersinJohannesburgcalled“humanity'sbestinvestmenttoachievedevelopmentandsustainability”.
简介:浙江黄龙体育中心主体育场挑蓬采用斜拉索网壳结构,由网壳、内外环梁、斜拉索、稳定索等组成,网壳两边分别支承在外环梁(预应力砼梁)和内环梁(钢箱形梁)上,内环梁通过斜拉索悬挂在两端的预应力砼吊塔上,由此形成了一个由吊塔、斜拉索、内环梁、外环梁、网壳和稳定索组成的复杂空间结构。根据结构的设计意图,网壳与环梁分别从两端(吊塔边)向中间安装,在中间合拢时要控制好温度;在安装过程中,网壳不能与内环梁相连,使得网壳的安装具有较大的难度。本文论述了网壳挑蓬结构的安装工艺和方法,并针对如何控制屋盖结构合拢时的温度,怎样保证网壳与内环梁的同步施工而不相互影响等问题作详细的介绍。