Permafrost and taliks and their changes on the south and north banks of the Tuotuo River in the Qinghai-Tibet Plateau under the climate warming北大核心CSCD

The distribution of permafrost and taliks is very complex in the Tuotuo River Basin(TRB), which is located in interior of the Qinghai-Tibet Plateau. Characterizing the spatial distribution and the thermal stability of permafrost and taliks is of great significance to community activities and engineering construction in TRB. Based on the zonation of permafrost and talik distribution around TRB conducted in the 1980s, the soil temperature and its variation process of permafrost and taliks in the south and north banks of the Tuotuo River were analyzed by using the observation data of five boreholes(N1~N5)along the Qinghai-Tibet Railway in the north bank and five boreholes(S1~S5)on the first terrace in the south bank. The results showed that, under the climate warming, permafrost and taliks in the north banks experienced significant degradation and warming process. From 2005 to 2020, the permafrost at the N1 borehole has undergone a significant down-draw degradation process, from extremely unstable and high-temperature permafrost to thawed zone. From 2005 to 2013, the annual average ground temperature of the talik at N2 increased at a rate of 0. 3~0. 4 °C·(10a)-1. At Maqutang on the south bank, permafrost prevails from the first-class terrace to the gentle slope of the Kaixinling Mountain, with both through and non-through taliks on the first-class terrace. The spatial distribution and the thermal stability of permafrost and talik in the TRB are further promoted by analyzing the changes in temperatures at boreholes in the basin. However, to meet the requirements of mapping and engineering construction of permafrost and taliks in the TRB, it is still necessary to carry out geological investigation with multiple methods and in-depth research on development mechanism of taliks in the future. © 2022 Nanjing Forestry University. All rights reserved.     

节理岩体结构面优势产状确定方法研究

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以三山岛金矿-510中段和-555中段为例,基于结构面实测数据,利用Matlab对结构面特征进行统计模型,进而实现了岩体裂隙网络Monte-Carlo模拟。然后结合分形理论确定了岩体质量的分维值。研究表明,-510中段和-555中段F3以北的岩体稳定性要好于F3以南的岩体稳定性,从定性和定量的角度对岩体质量进行了分析,为矿山的安全生产提供了一定的依据。     

黄土导热系数和比热容的实验研究

首先探讨了黄土导热系数和比热容的测试方法,组装形成黄土土样试验装置。然后取扰动黄土配制不同密度、不同含水量试样进行试验,测得黄土导热系数和比热容。实验结果揭示出,在含水量一定的情况下,导热系数和比热容随密度增大而增大;在密度相同的情况下,导热系数和比热容亦随含水量的增大而增大。进一步分析得到根据土体含水量、密度确定导热系数和比热容的关系式。相对于随密度的变化,黄土导热系数和比热容随含水量的变化尤为显著,含水量变化可以引起热参数较大的变化。