关于湿陷性黄土试验方法的初步探讨

文章介绍了黄土湿陷性试验的两种试验方法,对黄土湿陷机理作了简要分析,并对双线法的误差及其修正进行了讨论。     

A recording phase lag between ocean and continent climate changes: Constrained by the Matuyama/Brunhes polarity boundary

The Matuyama/Brunhes polarity boundary (MBPB) is recorded in Chinese loess L8, which is associated with the glacial period. It is proved that loess L8 is capable of recording earth’s secular variation, and the lock-in depth in Chinese loess is no more than that of marine sediments. Comparison with the location of MBPB in Chinese loess and marine sediments, it is put forward that there is a recording phase lag between ocean and continent climate changes.     

Chronology of environmental events over East Asia during the past 130 ka

In the transitional region between the Loess Plateau and deserts, 4 sections located respectively at Yuling, Hengshan, Dingbian and Huining of China are studied. The high-resolution paleoclimatic records obtained show that environmental events on varying time scales have happened over East Asia. These events are dated with the time scales established using the recently-developed approach of Automatic Orbital Tuning. This leads to the establishment of the chronology of the environmental events.     

兰州马兰黄土的工程地质特性

采用不同的原位及室内测试方法，分别在兰州和欧洲两地对兰州地区马兰黄土的物理、力学及水理性质进行了系统测试。通过对大量试验资料的统计、计算和分析研究，综合评价了兰州地区马兰黄土的工程地质性质，揭示了其基本规律，初步探讨了马兰黄土沉积区的地质灾害成因。     

泰安岩溶水系统地下水动力环境演化规律研究

从地下水水位的时空演化、地下水水位降落漏斗的形成和演化、地下水埋藏条件的演化以及地下水流场的变异等方面，分析总结出泰安岩溶水系统地下水动力环境的演化规律；指出岩溶水系统地下水动力环境演化是人类活动的结果。     

Loess-soil sequences in southern Anhui Province： Magnetostratigraphy and paleoclimatic significance

Two parallel loess-soil sequences from Xuancheng and Fanchang in southern Anhui Provinces are dated using geomagnetic and luminescence methods.The Brunhes/Matuyama(B/M) reversal boundary is recognized within the lower part of the so-calles Vermiculated Red Soil (VRS) in the Xuancheng section while the entire Fanchang sequence is of Brunhes age.This indicated that the most recent VRS in southern China,a stratigraphic marker and an indication of extremely warm-humid conditions,was formed during the middle Pleistocene,chronologically correlative with the S4 and S5 soil units in northern China.Microscopic and sedimentologic in vestigations reveal that eolian deposition started in this region at about 0.85 MaBp,roughly synchronous with the well-known Mid-Pleistocene climate change of global significance.The strengthening of both summer and winter monsoon circulations and the consequent river hydrological changes at that time would have provided favorable conditions for sustained eolian deposition in the middle-lower reaches of the Yangtze River since 0.85 MaBP.     

黄土高原坡耕地生态退耕的植被建设研究--以陕西省黄土高原生态退耕县为例

通过对陕西省黄土高原地区生态退耕县坡耕地的数量、质量调查，指出实现坡耕地退耕的措施?提出在各生态类型区的自然条件下适宜种植的树种、草种和提高植被成活率的途径，分析坡耕地生态退耕后植被建设将带来的经济和生态效益，对整个黄土高原地区的植被建设具有重要的指导作用。     

圩区水环境治理规划及地下水溶质运移预测模拟

以中国南方平原圩区为研究对象，分析圩区堤防采用垂直封闭截渗技术后对圩内水环境的影响，并建立封闭圩区水环境规划及地下水溶质运移数学模型，通过求解，得出圩区的最优水面率和滞蓄水深、最优外排装机容量和内排装机容量以及大堤的最优封闭率，同时预测了区域内地下水位及地下水污染动态变化情况。     

关于黄土湿陷起始压力、湿陷起始含水量的探讨

在不同压力下，湿陷性黄土试验实测变形与含水量关系曲线族上有一变形陡增段，陡增段的出现表明在此含水量变化区间变形对含水量变化敏感。变形分界压力和变形分界含水量概念以及相关经验公式的初步探讨，不仅为研究黄土湿陷起始压力、湿陷起始含水量问题提供了一个新思路，而且在工程实践中也具有一定的实用价值。