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Characteristics of thawed interlayer and its effect on embankment settlement along the Qinghai-Tibet Railway in permafrost regions

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Journal of Mountain Science 2018年第5期15卷 1090-1100页

作者： SUN Zhi-zhong MA Wei ZHANG Shu-juan MU Yan-hu YUN Han-bo WANG Hong-lei State Key Laboratory of Frozen Soil Engineering Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China Beiluhe Observation and Research Station on Frozen Soil Engineering and Environment in Qinghai-Tibet Plateau Coldand Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Golmud 816000China University of Chinese Academy of Sciences Beijing 100049 China

The formation of thawed interlayer beneath embankment can result in embankment settlement in permafrost regions. Based on the data on ground temperatures and deformations beneath the embankment, observed in-situ along the QinghaiTibet Railway in permafrost regions from 2006 to2013, characteristics of the thawed interlayer beneath the embankment and its influence on the embankment settlement are studied. The results indicate that the thawed interlayer hardly forms beneath the natural field, and beneath the embankments from the Qinghai-Tibet Railway the thawed interlayer develops widely, and it can be refrozen totally in the regions with lower mean annual ground temperature, and developed further in the regions with higher mean annual ground *** thawed interlayer is closely related to the embankment settlement. The ice content of permafrost underlying the thawed interlayer influences the settlement of embankment. The higher the ice content is, the larger the settlement is, and vice versa. The increase in thickness of thawed interlayer mainly results from the decline of artificial permafrost table in high-temperature permafrost regions.

关键词： In-situ monitoring Qinghai-TibetRailway Embankment settlement thawed interlayer

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Shear properties of thawed natural permafrost by bender elements

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Research in Cold and Arid Regions 2017年第4期9卷 343-351页

作者： Feng Zhang ZhaoHui (Joey) Yang JiaHui Wang HaiPeng Li Benjamin Still School of Transportation Science and Engineering Harbin Institute of Technology Harbin Heilongjiang 150090China College of Engineering University of Alaska Anchorage Anchorage Alaska 99508 USA School of Civil Engineering Harbin Institute of Technology Harbin Heilongjiang 150090 China State Key Laboratory of Geo-mechanics and Deep Underground Engineering China University of Mining and Technology Xuzhou Jiangsu 21116 China

thawed permafrost could cause a serious stability problem for foundations and oil-wells in cold regions. A non-damage testing procedure, employing the Bender Element Method, was used for permafrost samples collected from a continuous frozen core obtained from the North Slope of Alaska, USA. The wave velocity and modulus of thawed permafrost were investigated on various isotropic confining pressure from 0 kPa to 400 kPa per 100 kPa. The received shear wave propagation was recorded, and the elastic wave theory was used to calculate shear modulus. Finally, the shear modulus affected by confining pressure, water content and dry density were analyzed and discussed, and a regression formulation of shear modulus based on the Janbu Model for thawed silty and sandy permafrost were proposed and validation.

关键词： shear velocity shear modulus thawed natural permafrost bender element

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Characteristics of thawed interlayer and its effect on settlement beneath embankment in permafrost regions--A case study for the Qinghai-Tibet Highway

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Research in Cold and Arid Regions 2017年第5期9卷 447-454页

作者： ZhiZhong Sun HongLei Wang WenJie Feng YongZhi Liu ShuJuan Zhang State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou Gansu 730000 China University of Chinese Academy of Sciences Beijing 100049 China Beiluhe Observation and Research Station on Frozen Soil Engineering and Environment in Qinghai-Tibet Plateau Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou Gansu 730000 China

Based on ground temperatures and deformations monitored at the Xieshuihe site along the Qinghai-Tibet Highway(QTH)in permafrost regions from 2004 to 2015,variation of artificial permafrost table(APT),maximum frozen depth(MFD),thawed interlayer thickness(TIT)and ground temperature beneath embankment is analyzed,*** results indicate that under the embankment,the change of APT occurred from October to December of that year and presented a deepening *** change of MFD occurred from April to June of that year with no obvious change trend,and TIT had an increasing trend year by year,which mainly resulted from the deepening artificial permafrost *** annual ground temperature at 0.5 m depth was 3.91°C higher beneath the embankment center than that under the natural *** rising ground temperature at shallow layer of embankment resulted in the development of thawed interlayer beneath the embankment and warming of underlying *** settlement is closely associated with *** settlement easily occurs when permafrost with higher ice content exists under the thawed interlayer,and in turn the settlement is smaller when permafrost with lower ice content exists under the thawed interlayer.

关键词： thawed interlayer embankment in-situ monitoring settlement Qinghai-Tibet Highway

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Sperm Quality in Holstein Bulls Friesian and Brahmans of Frozen Semen Commercially

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Open Journal of Animal Sciences 2015年第3期5卷 229-231页

作者： Alejandro Córdova-Izquierdo Gustavo Ruiz-Lang Román Espinosa-Cervantes Adrían Emmanuel Iglesias-Reyes Maximino Méndez-Mendoza Rubén Huerta-Crispín Abel Edmundo Villa-Mancera Ma. De Lourdes Juárez-Mosqueda Pedro Sánchez-Aparicio Jaime Olivares-Pérez Juan Eulogio Guerra-Liera Gerardo Cansino-Arroyo Departamento de Producción Agrícola y Animal Universidad Autónoma Metropolitana Unidad Xochimilco México D.F. México Facultad de Veterinaria Benemérita Universidad Autónoma de Puebla Puebla México Departamento de Morfología FMVZ-UNAM México D.F. México Facultad de Veterinaria Universidad Autónoma del Estado de México Toluca México Unidad Académica de Medicina Veterinaria y Zootecnia Universidad Autónoma de Guerrero Guerrero México Facultad de Agronomía Universidad Autónoma de Sinaloa Culiacán México División Académica de Ciencias Agropecuarias Universidad Juárez Autónoma de Tabasco Villahermosa México

The aim of this study was to assess sperm quality (motility, viability and acrosomal integrity) sperm from commercially frozen semen straws two breeds of bulls Bos taurus (holstein Frisian) and Bos indicus (Brahman). 9 commercial straws 0.5 ml of Holstein bull semen and 9 Brahman bull were thawed, they were kept for two hours at room temperature and motility, viability and acrosomal integrity (NAR) was assessed. The results were 30% motility, viability 40% and 30% of NAR in the Holstein breed. Brahma race for motility 40%, 50% and 40% viability was obtained NAR. In conclusion, according to the results of the variables analyzed, the Brahman breed in sperm quality was better than the Holstein breed;however, the results of both races meet minimum standards of quality sperm for use in artificial insemination (AI) field level.

关键词： Semen thawed Bulls Frozen Semen Sperm Quality

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