Results 21 to 30 of about 1,003 (145)

Mechanism analysis on anisotropic degradation of sandstone in freeze thaw environment based acoustic emission [PDF]

open access: yes
In the freeze-thaw environments, the fracturing of bedding rock poses a significant threat to the stability of the projects in cold regions, leading to potential engineering accidents.
Bing LIU   +4 more
core   +1 more source

复合侵蚀作用下砒砂岩坡面产流产沙过程试验

open access: yesShuitu Baochi Xuebao, 2020
通过模拟室内风力、水力、冻融条件,进行单一水蚀、冻融+水蚀、冻融+风蚀+水蚀3种营力组合试验,揭示了复合侵蚀条件下的砒砂岩产流产沙变化规律。结果表明:(1)相同降雨条件下,冻融+水蚀、冻融+风蚀+水蚀试验的径流量均为水蚀试验的1.2倍,产沙量分别为水蚀试验的2.4,2.8倍。冻融能够增大砒砂岩产流产沙量,风蚀对增加侵蚀产沙量的作用较小。(2)砒砂岩产流产沙过程的峰值及变幅随营力种类的增多而增大,单一水蚀的产流产沙过程相较于复合营力作用下的水沙过程具有显著的坦化特征。(3)复合侵蚀作用使初始入渗率增加 ...
卫午毓   +4 more
doaj  

冻融循环对黑土团聚体稳定性与微结构特征的影响

open access: yesShuitu Baochi Xuebao, 2022
冻融循环作用下的土壤结构变化被认为是融雪期黑土坡面土壤侵蚀加剧的主要原因之一, 土壤团聚体稳定性与团聚体微结构是影响土壤可蚀性的关键因子。基于控制条件土壤冻融模拟试验, 采用湿筛法、扫描电子显微技术(SEM)和Image-Pro Plus(IPP)图像分析处理相结合的方法, 分析了冻融循环过程中黑土团聚体微结构的动态变化特征, 阐明了土壤团聚体水稳定性与团聚体微结构特征的内在联系。结果表明: (1)冻融循环对黑土团聚体水稳定性整体呈破坏作用。该作用在微观层面上表现为冻融循环驱动土壤孔隙趋于长条状发育 ...
王文刚   +4 more
doaj  

Evaluation of freeze-thaw wind erosion and analysis of influencing factors on the Tibetan Plateau based on the improved RWEQ [PDF]

open access: yes
Freeze-thaw wind erosion refers to the process in which temperature fluctuations cause changes in the surface structure, significantly impacting on the formation of surface landform and soil properties. However, due to the particularity and complexity of
Fujun NIU   +4 more
core   +1 more source

Three dimensional efficient regularized meshfree simulations of slope failure induced by rainfall and freeze-thaw processes [PDF]

open access: yes, 2015
边坡失稳破坏是一类常见的自然灾害形式。边坡破坏诱发的因素很多,其中尤以降雨引发的滑坡灾害最为突出。同时,随着西部大开发的深入,寒冷地区冻融作用导致的边坡破坏也日益受到重视。然而,边坡失稳涉及到土体骨架、水(冰)、空气等多相耦合即相互作用,是一个复杂的非饱和土体大变形损伤破坏过程,需要借助精确高效的数值方法进行分析、预测和预防。本文利用无网格法仅采用节点离散、适于大变形分析的优点,着重研究了降雨及冻融影响下边坡破坏的三维高效无网格数值模拟方法。 本文首先针对降雨诱发边坡破坏问题 ...
孙明
core  

Effect of Freezing on Wind Erosion Resistance of Sand Dune Soil [PDF]

open access: yes
[Objective] To investigate the effect of winter soil freezing on soil erodibility and anti-erodibility in the Yellow River section of the Ulan Buh Desert.
DOU Chunhua   +4 more
core   +1 more source

冻融循环次数和土壤含水率对油松林土壤团聚体及有效态微量元素的影响

open access: yesShuitu Baochi Xuebao, 2020
以王茂沟流域典型人工油松林土壤为对象,研究了不同冻融循环次数(0,3,9次)和不同土壤含水率(40%FC,60%FC,80%FC)条件下土壤团聚体组成和团聚体中4种有效态微量元素(Cu、Fe、Mn、Zn)的演变特征。结果表明 ...
姚珂涵, 肖列, 李鹏, 高扬
doaj  

Experimental study on the synergistic effect of coir fiber and lime to improve soil performance [PDF]

open access: yes
To solve the problems of poor engineering properties of clay and low utilisation of coir fiber, a green and high-performance soil was obtained by using coir fiber in synergy with lime for clay reinforcement.
Cuiying WANG   +4 more
core   +1 more source

模拟降雨下前期含水量对冻融坡面产流产沙过程的影响

open access: yesShuitu Baochi Xuebao, 2017
为了探究不同前期含水量条件下冻融作用对坡面降雨侵蚀的影响,采用室内冻融和人工模拟降雨方法研究了不同含水量条件下冻融坡面与未冻融坡面的降雨侵蚀特征。结果表明:黄土坡面的产流时间随前期含水量增大呈先增大后减小的规律,冻融作用使黄土坡面产流时间滞后,其中含水量为20%的坡面经过冻融作用滞后62.50%,最为明显。在产流过程中,20%含水量的冻融坡面比未冻融坡面产流总量低9.14%存在极显著性差异(P<0.01)。在产沙过程中,20%和25%含水量的冻融坡面比未冻融坡面产沙总量减小28%,存在极显著性差异(P ...
段金晓   +7 more
doaj  

冻融循环和土壤性质对东北黑土抗剪强度的影响

open access: yesShuitu Baochi Xuebao, 2020
为了揭示东北黑土区季节性冻融循环作用和土壤性质对土壤可蚀性的影响,采集黑龙江省宾县典型薄层黑土区(BX)和克山县典型厚层黑土区(KS)0—20 cm的耕层土壤,通过室内冻融循环模拟和土壤直剪试验,分析了冻融作用和土壤性质对土壤抗剪强度的影响。结果表明:(1)经历1次冻融作用后BX和KS 2种供试土壤抗剪强度分别减小3.9%和9.2%,二者黏聚力分别减小15.2%和29.4%,内摩擦角分别减小1.4%和3.6%。经历7次冻融作用后,BX和KS 2种供试土壤抗剪强度分别减小9.1%和15.1 ...
左小锋   +6 more
doaj  

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