MoNo 140672

Brown sediment with clasts ranging from small to large in size. Clast shape ranges from sub-angular to sub-rounded. Many larger clasts appear fractured and/or weathered. Lineations and rotation structures can be commonly seen. Comet structures are also present. Minor amounts of grain crushing and stacking can also be seen.

16 AUG B-I-A

Dark brown sediment with clasts ranging from small to large. Clast shape ranges from angular to sub-rounded. Rotation structures and comet structures can be commonly seen throughout the sample. Lineations along with minor amounts of grain crushing can also be seen in this sample.

A-3-B

Dark grey sediment with clasts ranging from small to large. Clast shape ranges from angular to sub-rounded in shape. Lineations are abundant in this sample. Comet structures can also be seen . There are minor amounts of rotation structures in this sample, and some clasts have faint rotation structures surrounding them. Minor amounts of grain crushing can also be seen.

MF-1

Brown sediment with well dispersed clasts ranging from small to large. Clast shape ranges from angular to sub-rounded. Lineations and rotation structures can be seen in this sample. Minor amounts of edge-to-edge grain crushing can also be seen.

MF-2

Brown sediment with clasts ranging from small to large. The clast shape ranges from angular to sub-rounded. The clasts are generally well dispersed but edge-to-edge grain crushing is present. A few lineations and faint rotation structures can also be seen.

RRC-1

Brown sediment with clasts ranging from small to large in size. Clast shape ranges from angular to sub-rounded. Lineations and rotation structures can be commonly seen throughout the sample. Minor amounts of comet structures, grain crushing and grain stacking can also be seen.

WRC-1

Light brown sediment with clasts ranging from small to large in size. Clast shape ranges from angular to sub-rounded. Grain crushing is present in this sample, along with grain stacking. Minor amounts of lineations, and faint rotation structures can also be seen.

1493 BH17 NP 2014

Brown sediment with clasts ranging from small to large. Clast shape ranges from angular to rounded. Lineations and comet structures are abundant throughout this sample. It also contains rotation structures and minor amounts of grain crushing.

1539 BH17 NP 2014

Brown sediment with clasts ranging from small to large. Clast shape ranges from angular to sub-rounded. Lineations are common throughout the sample. This sample also contains a clay domain, that appears very fine grained. Edge-to-edge grain crushing, comet structures, and rotation structures are also present.

1544 BH17 NP 2014

Brown sediment with inclusions of a clay rich domain. Clasts range from small to medium in size and angular to sub-rounded in shape. Lineations can be commonly seen throughout the sample, along with water escape structures in the clay rich domain. Rotation structures, comet structures, and grain crushing are also present.

长期施用氮、磷和有机肥对不同种植体系土壤有效硫累积的影响

以22年定位试验为基础,研究了长期施用氮、磷和有机肥(NPM)对不同种植体系土壤有效硫在剖面上分布与累积状况。结果表明,在60—80 cm土层各处理出现第一个累积峰,累积峰值为粮饲轮作31.3,玉米连作29.2,小麦连作27.9,粮豆轮作25.6,苜蓿连作24.0 mg/kg;在140—180 cm土层各处理又出现有效硫的第二个累积峰,累积峰值为粮饲轮作44.7,粮豆轮作43.1,小麦连作41.0,玉米连作39.7,苜蓿连作36.5 mg/kg。第二累积峰值均大于第一累积峰值。0—200 cm土层有效硫总累积量粮饲轮作高达746.3 kg/hm~2,其次为玉米连作640.6,粮豆轮作为638.3,小麦连作为622.4,苜蓿连作最小为557.3 kg/hm~2。长期施用磷肥和有机肥是有效硫在土壤中累积的主要因素,有效硫在土壤剖面上有向深层迁移的趋势。不同作物对硫的吸收利用差异和不同种植方式对有效硫的累积与分布产生影响。

黄土高原半干旱区苜蓿草地土壤干燥化特征与粮草轮作土壤水分恢复效应

实地测定了黄土高原半干旱区固原不同生长年限苜蓿草地和连作8a苜蓿草地翻耕轮作不同年限粮食作物后深层土壤水分特征,分析了苜蓿草地土壤干燥化特征和粮草轮作对土壤水分的恢复效应。结果表明:(1)苜蓿连作1a、5a、8a和12a等4类苜蓿草地0~1000cm土层平均土壤湿度值为6.6%,平均土壤水分过耗量702.8mm,平均土壤干燥化速率147.1 mm/a,达到强烈干燥化程度,苜蓿连作5a土壤干层深度超过1000cm,苜蓿连作8a土壤干层深度超过1360cm,苜蓿草地合理利用年限为7a。(2)连作8a苜蓿草地翻耕并轮作4~7a和25a粮食作物等5类粮田0~1000cm土层土壤湿度介于6.74%~11.95%,土壤贮水量恢复值介于210.6~887.3mm,平均土壤水分恢复速率为80.8mm/a。轮作6a后粮田土壤干层轻度恢复程度以上深度达到1000cm。通过粮草轮作使苜蓿草地土壤湿度恢复到当地土壤稳定湿度需要13a以上。黄土高原半干旱区适宜的粮草轮作模式为:7a苜蓿→13a粮食作物。

滑坡型泥石流转化机理研究—以四川省达县青宁乡滑坡为例

Slide-debris flow is debris flow which is transformed from landslide consecutively in a short time, it comprises of two phases: First, Landslide starts to slide; Second, landslide changes to debris flow. Slide-debris flow which brings great property and life loss happens frequently at home and abroad. In order to forecast the happening possibility and scope of slide-debris flow, transfromation mechanism of Slide-debris flow must be studied. Research on transformation mechanism of slide-debris flow is intersectant science of landslide kinetics and debris flow starting theory, It is a fringe problem as well as front problem of geological hazard. This paper takes Qingning slide-debris flow in Da County, Sichuan Province for example and has studied the mechanism of its instability and transfromation into debris flow through indoor test (including usual soil test and ring shear test) and digital modeling method.The research gets the following conclusions. Qingning Landslide took place mainly because of confined water head arising from rainfall infiltration. Before Landslide occurring, it rained continuously for 22 days, accumulated precipitation arrived at 521.6mm.Investigation shows that strata of Qingning Landslide contains quaternary loose accumulation, slip soil and highly weathered bedrock, which is a good condition for formation of confined water in the slope. Further more, groundwater seepage in the slope body and corresponding slope safety factor before landslide occurring have been computed through finite element method. The result shows that because of infiltration of rainfall, confined water head in the slope arose sharply, accordingly, the safety factor of the slope declined quickly. The result also shows that force put on the slide body by the rock mass detached from Dazhaiyan mountain was the direct factor for landslide occurring. Qingning slide-debris transformation mode has been summarized, the process the landslide changed into debris flow is divided into three phases in the prospective of macroscopic geological condition: landslide occurring, transformation and debris flow. Landslide occurring phase is from slope’ local creeping slide to Landslide occurring; transformation phase contains slide body sliding on the slide bed after slide occurring and sliding on the slope after shearing opening; debris flow phase is that slide body breaks up completely and flows downward into the ditches. The transformation mechanism of Qingning slide-debris flow has been studied through indoor ring shear test of slip soil. The result shows that transformation mechanism contains two points: first, during slide body sliding on the slide bed and slope after shearing opening, shearing shrinkage, grain crushing and grain layering brought about declining of its volume and produced excess pore water pressure, and because producing velocity of excess pore water pressure is much greater than its dissipating velocity, shear strength of slide body decreased sharply because of accumulated pore water pressure. Second, grains crushing and grains layering during slide body sliding brought about thick liquefied layer at the bottom of the slidebody, liquefied layer contained high water content and its shear strength was very low, its thickness increased as the sliding displacement increasing. Liquefied layer makes slide body sliding fast and easily break down to debris flow. Excess pore water pressure and liquefied layer made shear strength of slidebody became very low, furthermore, water in the pit of slope joining in the slidebody was also a facter that made slidebody accelerate the transformation. Influence of slide body thickness and fine grains content to transformation of slide-debris flow has been studied through ring shear test. The result reaches two conclusions. First, thickness of slide body affects transformation of slide-debris flow by two ways, porewater pressure and effect of “soft base” increases as thickness of slide body increasing.so the thicker slide body is ,the easier transformation is. Second, actual dissipating velocity of porewater pressure should be considered when studying the influence of fine grains content to tranformation of slide-debris flow. There should be a critical content of fine grains which makes the difference of producing and dissipating velocity of water pore pressre greatest, this value is the best for slide-debris transformation. The whole process of slide-debris flow transformation is reproduced through discrete element method. Transformation mechanism of slide-debris flow is studied through monitoring various parameters including pore water pressure, grain crushing and grain layering in the slide body during the transformation. The result confirms and supplements the transformation mechanism of slide-debris flow got from ring shear test well.

南沙群岛工程地质环境分区与珊瑚礁工程地质特性研究

Nansha Islands as sacred territory of China, containing abundant natural resources is the important area of sustaining development of Chinese people. Safeguarding and developing Nansha Islands has become one important part to develop ocean resource of China in 21 century. Engineering geological problems will be faced inevitably in the processes of engineering construction. Coral reef is a new kind of soil and rock and has special engineering characteristics. This doctoral dissertation researches deeply and systematically the regional engineering geology environmental properties and quality, engineering geological characteristics of coral reefs sand on the basis of synthetic analysis of hydrology, climate, geology, geomorphology and engineering field exploration information and combining the experimental data. 1. Put forward the division program of engineering geological environment of Nansha Islands according to the data of hydrology, geology and sediments, and also deeply study the properties of each division. Evaluate the quality of engineering geological environment by fuzzy mathematics and draw the evaluation map of quality of engineering geological environment. The research work provides background support of engineering geological environment to program of resource development in Nansha Islands. 2. Structures of coral reefs have been analyzed. The model of engineering geological zone has been proposed on the basis of geomorphologic zone and combining the strata and ocean dynamic environment. The engineering construction appropriation of each zone is praised. 3. The physical and mechanical properties of coral sands are researched. The results show that coral sands have high void ratio, non-regular shape, easy grain crushing and large compressibility. Shear-expansion takes place only at very low confining pressure and shear-contraction of volumetric strain occurs at higher confining pressure. Internal friction angle decreases with the increasing of confining pressure. The grain crushing property is the main factor influencing the mechanical characteristics. 4. A revised E-ν constitutive model is proposed which considers the change of internal friction angle with confining pressure, and parameter values are also determined. 5. The stability of Yongshu Reef by is analysed for the purpose of serving engineering struction. The process and mechanism of deformation and failure of foundation and slope is analyzed by finite-element method.

HG 186.15-186.25-3

Major grain crushing towards the centre of the section. A few lineations and grain stacks also present.