红层泥岩水敏性高,作路基填料时可用石灰改良。受季节变化影响,路基基床经历干湿循环,导致服役性能降低。为研究干湿循环下改良填料力学特性劣化规律,开展一系列干湿循环试验、无侧限抗压试验和弯曲元试验测定改良填料无侧限抗压强度和...红层泥岩水敏性高,作路基填料时可用石灰改良。受季节变化影响,路基基床经历干湿循环,导致服役性能降低。为研究干湿循环下改良填料力学特性劣化规律,开展一系列干湿循环试验、无侧限抗压试验和弯曲元试验测定改良填料无侧限抗压强度和小应变刚度。结合连续滴水扫描电镜(scanning electron microscope,简称SEM)试验,揭示干湿循环后填料微观结构劣化特征。结果表明:低幅度循环下试样在干侧和湿侧均产生体胀。高幅度循环下试样在湿侧产生体胀。在干侧先产生体缩,随循环次数增加,即使含水率较低,试样也产生体胀。体胀导致强度和小应变刚度均有不同程度的劣化。当试样产生体缩时,强度有所增长,但小应变刚度由于裂缝衍生而持续衰减。试样强度随损伤体变可用统一劣化方程表示。但高幅度循环下试样干燥后的小应变刚度远低于劣化线,且劣化速率远大于强度。试样滴水后能维持基本形貌,但观察到团聚体松散、微粒剥落和新生裂缝等结构劣化特征,从而导致宏观力学性能衰减。展开更多
唐人的避暑生活丰富多彩,各个阶层的人群有种类繁多的避暑措施,唐人还很注重居处环境的安排布置,利用池塘、树木营造清凉幽静的生活环境。唐人的避暑生活带动了诗歌的创作,唐人在寻找避暑处所时留下了一首首社交性质的诗歌,同时,独处时...唐人的避暑生活丰富多彩,各个阶层的人群有种类繁多的避暑措施,唐人还很注重居处环境的安排布置,利用池塘、树木营造清凉幽静的生活环境。唐人的避暑生活带动了诗歌的创作,唐人在寻找避暑处所时留下了一首首社交性质的诗歌,同时,独处时也时常创作寄友、招客主题的诗歌。唐代避暑诗歌的创作往往摒除了浮躁、程式化的弊端,注重诗歌艺术的研磨,诗歌多注重锤炼,富于自省气质。The Tang people have a rich and colorful life in summer, and people of all walks of life have a variety of summer measures. The Tang people also pay great attention to the arrangement of the living environment, using ponds and trees to create a cool and quiet living environment. The life of the Tang people in the summer led to the creation of poems. When the Tang people were looking for a place to escape the summer, they left poems of a social nature one after another. At the same time, they often created poems on the theme of sending friends and inviting visitors when they were alone. The creation of summer poems in the Tang Dynasty often got rid of the drawbacks of impetuousness and stylization, and paid attention to the grinding of poetry art, and poems paid more attention to tempering, rich in introspection temperament.展开更多
红层泥岩填料水敏性高,路基状态受含水率影响显著。为研究含水率对红层泥岩填料动力特性的影响,开展了41组动三轴试验,5组压汞(mercury intrusion porosimetry,MIP)试验和3组扫描电镜(scanning electron microscope,SEM)试验,结果表明:...红层泥岩填料水敏性高,路基状态受含水率影响显著。为研究含水率对红层泥岩填料动力特性的影响,开展了41组动三轴试验,5组压汞(mercury intrusion porosimetry,MIP)试验和3组扫描电镜(scanning electron microscope,SEM)试验,结果表明:填料等效模量和阻尼比具有应变振幅相关性,可用Hardin-Drnevich双曲线模型表述。随动应力增大,填料累积变形由稳定型向破坏型过渡。含水率影响填料累积变形响应和临界动应力,相同应力水平下干侧填料累积变形明显低于湿侧填料,达到变形限值的振次高于湿侧填料。干侧填料临界动应力大于湿侧,临界动应力随初始吸力增加而增加,可用VG模型表述。从微观结构看,含水率增加将导致填料微观孔隙结构由单峰形态向双峰形态转变,填料组构由密实稳定逐渐向无序松散转变,最终在宏观上表现为干侧填料动力特性优于湿侧填料。填料临界动应力与静强度比值为65%~75%,采用静强度作设计指标将高估路基承载力。推荐采用5.0%~7.0%含水率填料填筑红层泥岩路基。展开更多
文摘红层泥岩水敏性高,作路基填料时可用石灰改良。受季节变化影响,路基基床经历干湿循环,导致服役性能降低。为研究干湿循环下改良填料力学特性劣化规律,开展一系列干湿循环试验、无侧限抗压试验和弯曲元试验测定改良填料无侧限抗压强度和小应变刚度。结合连续滴水扫描电镜(scanning electron microscope,简称SEM)试验,揭示干湿循环后填料微观结构劣化特征。结果表明:低幅度循环下试样在干侧和湿侧均产生体胀。高幅度循环下试样在湿侧产生体胀。在干侧先产生体缩,随循环次数增加,即使含水率较低,试样也产生体胀。体胀导致强度和小应变刚度均有不同程度的劣化。当试样产生体缩时,强度有所增长,但小应变刚度由于裂缝衍生而持续衰减。试样强度随损伤体变可用统一劣化方程表示。但高幅度循环下试样干燥后的小应变刚度远低于劣化线,且劣化速率远大于强度。试样滴水后能维持基本形貌,但观察到团聚体松散、微粒剥落和新生裂缝等结构劣化特征,从而导致宏观力学性能衰减。
文摘唐人的避暑生活丰富多彩,各个阶层的人群有种类繁多的避暑措施,唐人还很注重居处环境的安排布置,利用池塘、树木营造清凉幽静的生活环境。唐人的避暑生活带动了诗歌的创作,唐人在寻找避暑处所时留下了一首首社交性质的诗歌,同时,独处时也时常创作寄友、招客主题的诗歌。唐代避暑诗歌的创作往往摒除了浮躁、程式化的弊端,注重诗歌艺术的研磨,诗歌多注重锤炼,富于自省气质。The Tang people have a rich and colorful life in summer, and people of all walks of life have a variety of summer measures. The Tang people also pay great attention to the arrangement of the living environment, using ponds and trees to create a cool and quiet living environment. The life of the Tang people in the summer led to the creation of poems. When the Tang people were looking for a place to escape the summer, they left poems of a social nature one after another. At the same time, they often created poems on the theme of sending friends and inviting visitors when they were alone. The creation of summer poems in the Tang Dynasty often got rid of the drawbacks of impetuousness and stylization, and paid attention to the grinding of poetry art, and poems paid more attention to tempering, rich in introspection temperament.
文摘红层泥岩填料水敏性高,路基状态受含水率影响显著。为研究含水率对红层泥岩填料动力特性的影响,开展了41组动三轴试验,5组压汞(mercury intrusion porosimetry,MIP)试验和3组扫描电镜(scanning electron microscope,SEM)试验,结果表明:填料等效模量和阻尼比具有应变振幅相关性,可用Hardin-Drnevich双曲线模型表述。随动应力增大,填料累积变形由稳定型向破坏型过渡。含水率影响填料累积变形响应和临界动应力,相同应力水平下干侧填料累积变形明显低于湿侧填料,达到变形限值的振次高于湿侧填料。干侧填料临界动应力大于湿侧,临界动应力随初始吸力增加而增加,可用VG模型表述。从微观结构看,含水率增加将导致填料微观孔隙结构由单峰形态向双峰形态转变,填料组构由密实稳定逐渐向无序松散转变,最终在宏观上表现为干侧填料动力特性优于湿侧填料。填料临界动应力与静强度比值为65%~75%,采用静强度作设计指标将高估路基承载力。推荐采用5.0%~7.0%含水率填料填筑红层泥岩路基。
