为了研究航道开挖对新老护岸结构的影响,依托东宗线航道四改三工程,利用大型土工离心模型试验平台研究航道开挖对老挡墙护岸结构、新施工钢板桩的受力和变形特征的影响,得出航道开挖过程中板桩两侧土压力的分布规律。结果表明,随开挖深...为了研究航道开挖对新老护岸结构的影响,依托东宗线航道四改三工程,利用大型土工离心模型试验平台研究航道开挖对老挡墙护岸结构、新施工钢板桩的受力和变形特征的影响,得出航道开挖过程中板桩两侧土压力的分布规律。结果表明,随开挖深度增加,靠岸侧(主动侧)土压力逐渐减小;受板桩位移、变形及离心模型试验重液影响,临水侧(被动侧)土压力部分减小,底部土压力增大。开挖卸载导致老挡墙呈现向水侧移动且向后翻转的趋势。设计工况的极限开挖深度约为3.6 m,此时钢板桩顶部帽梁的水平位移达到0.069 m;对于6、8和10 m 3种长度的板桩,其极限开挖深度约为0.5~0.6倍桩长,且随着桩长增加极限开挖深度逐渐降低。研究得出不同板桩长度下开挖深度的阈值,可为工程建设提供技术参数。展开更多
Poly(aryl ether ether ketone ketone)(PEEKK) is a kind important high-performance polymers due to their excellent thermal stability a nd other outstanding properties similar to PEEK and PEKK.However,the PEEKK’s ins ol...Poly(aryl ether ether ketone ketone)(PEEKK) is a kind important high-performance polymers due to their excellent thermal stability a nd other outstanding properties similar to PEEK and PEKK.However,the PEEKK’s ins olubility in common solutions and high melt point restrict its processing and ap plications.In this paper,a series of random copolymers composed of poly(aryl eth er ether ketone ketone)(PEEKK)/poly(aryl ether ketone ether ketone ketone) cont a ining bis(o-metheyl) moiety(DM-PEKEKK) were prepared by low temperatur e so lution polycondensation of 4,4′-bis(2,6-dimethylphenoxy)diphenylketone (o -M 2DPOBP),1,4-dipheoxylbenzene(DPB) and terephthaloyl chlorde(TPC) in 1,2 -dichloroethane with the presence of AlCl 3 and DMF. The copolymers were chara cterized by FT-IR,DSC,WAXD,TGA,etc.The results show that glass transitio n te mperature increases greatly with the increasing of the ratio of o-M 2DPOBP /DPB,while melting temperature and crystallinity of copolymers decrease.The solu bility of the copolymers is improved greatly,while the copolymers still exhibit excellent thermostability.展开更多
文摘为了研究航道开挖对新老护岸结构的影响,依托东宗线航道四改三工程,利用大型土工离心模型试验平台研究航道开挖对老挡墙护岸结构、新施工钢板桩的受力和变形特征的影响,得出航道开挖过程中板桩两侧土压力的分布规律。结果表明,随开挖深度增加,靠岸侧(主动侧)土压力逐渐减小;受板桩位移、变形及离心模型试验重液影响,临水侧(被动侧)土压力部分减小,底部土压力增大。开挖卸载导致老挡墙呈现向水侧移动且向后翻转的趋势。设计工况的极限开挖深度约为3.6 m,此时钢板桩顶部帽梁的水平位移达到0.069 m;对于6、8和10 m 3种长度的板桩,其极限开挖深度约为0.5~0.6倍桩长,且随着桩长增加极限开挖深度逐渐降低。研究得出不同板桩长度下开挖深度的阈值,可为工程建设提供技术参数。
文摘Poly(aryl ether ether ketone ketone)(PEEKK) is a kind important high-performance polymers due to their excellent thermal stability a nd other outstanding properties similar to PEEK and PEKK.However,the PEEKK’s ins olubility in common solutions and high melt point restrict its processing and ap plications.In this paper,a series of random copolymers composed of poly(aryl eth er ether ketone ketone)(PEEKK)/poly(aryl ether ketone ether ketone ketone) cont a ining bis(o-metheyl) moiety(DM-PEKEKK) were prepared by low temperatur e so lution polycondensation of 4,4′-bis(2,6-dimethylphenoxy)diphenylketone (o -M 2DPOBP),1,4-dipheoxylbenzene(DPB) and terephthaloyl chlorde(TPC) in 1,2 -dichloroethane with the presence of AlCl 3 and DMF. The copolymers were chara cterized by FT-IR,DSC,WAXD,TGA,etc.The results show that glass transitio n te mperature increases greatly with the increasing of the ratio of o-M 2DPOBP /DPB,while melting temperature and crystallinity of copolymers decrease.The solu bility of the copolymers is improved greatly,while the copolymers still exhibit excellent thermostability.
