大型铰接并联六维测力平台摩擦建模

在已有制造工艺及标定技术基础上,为进一步改善大型铰接并联六维测力平台的测量精度,本文基于螺旋理论和影响系数原理,引入符号函数建立了Stewart结构大型铰接六维测力平台的摩擦模型。文中提出了关节摩擦对铰接并联六维测力平台测量精度的影响矩阵及I、H类误差表达式,绘制了在不同外载和关节摩擦系数条件下,六维测力平台的I、II类误差曲线,并总结丁关节摩擦和平台自重对测力平台测量精度的影响规律。为具有普通球形铰链人型Stewart平台六维测力下台精度的提高和改善提供了理论基础。

蛇形机器人行波运动的研究

对蛇形机器人的行波运动机理进行了研究,基于Serpenoid曲线建立了蛇形机器人行波运动的形状控制模型、运动学模型、机构动力学模型及环境动力学模型,给出了求解过程。仿真结果表明:在行波运动中,各关节输入力矩大小呈周期变化,且随其与蛇体重心距离的增加而减小。蛇体中心关节的最大输入力矩为蛇形机器人所需最大输入力矩。对称关节输入力矩幅值变化规律相同,但相差不同;运动初始弯角保持不变,关节输入力矩随着环境摩擦因数的增加而增加。环境摩擦因数保持不变,关节输入力矩随着初始弯角的增加而减小。

摩擦圆盘运动分解合成机构的理论设计及其运动学分析

提出了一种摩擦圆盘运动分解合成机构,理论分析表明这种运动分解合成机构具有非完整约束性,通过建立其运动学微分方程,对这种机构的运动变化和传递关系进行了计算机仿真分析,表明该运动传递机构具有可控性,这为该运动分解合成机构的应用奠定了基础。

一种可重构蛇形机器人的研究

提出了一种新型的可重构蛇形机器人机构。该机构主要特点是单关节结构模块化 ,具有可适应地面形状变化的柔性连接环节和类似于蛇腹鳞摩擦特性的机构底部 ,手动可重构 ,当单自由度关节轴线互相平行连接时 ,该机构可实现多种平面运动形式 ,当单自由度关节轴线垂直依次连接时 ,形成的蛇形机器人具有两自由度的关节 ,可进行多种空间运动。试验结果证实 ,该蛇形机构重量轻、控制简单、运动灵活 ,能够很好地仿生蛇的多种运动形式

基于加速度传感器反馈控制的谐波驱动系统的研究

在机器人驱动中经常采用谐波传动。但谐波减速器的柔性、非线性摩擦、随速度波动、低阻尼等因素会给负载端带来振动 ,导致工作端的轨迹跟踪精度不高。为了抑制其振动 ,实现高精度轨迹跟踪控制 ,提出利用加速度传感器反馈控制来抑制负载端的振动、力矩干扰和动力学效应 ,提高其响应性能。理论分析和实验结果证实了提出方法的可行性。

谐波驱动系统的特性及控制策略研究

谐波传动有很多优点，在机器人驱动中经常被使用．但谐波传动也有一些缺点，如柔性等因素影响负载端轨迹跟踪精度．本文系统地分析了谐波传动系统的动力学特性，建立了包括电机转子惯量在内的动力学模型，疽对系统进行全面实验研究的基础上总结出谐波传动系统中存在的问题，采用相应的基于传感器的控制策略克服存在的问题，提高系统的响应性能．从理论分析和实验结果证实了提出方法的可行性。

空间对接缓冲试验台对接环重力平衡技术

在空间对接机构地面缓冲实验平台上,为了模拟空间失重状态,研制了一种高精度、高响应速度的主动对接环重力平衡装置。介绍了对接环重力平衡装置的机构原理。对对接过程随动装置的随动性对系统的干扰进行了详细分析。进行了重力平衡器相关实验,从实验数据和理论分析可以得出:所设计的重力平衡装置完全满足对摩擦阻力和惯性阻力设计指标的要求,重力平衡达到1.1%的精度。

地下水位上升造成的黄土远程滑坡形成机理与数值模拟研究

Based on field survey, laboratory testing and numerical modeling, engineering characteristics of undisturbed loess and the mechanism of long-runout loess landslides caused by underground water level rise, as well as the formation conditions and spatial distribution of landslides, are systematically studied and analyzed. Loess landslides at south Plateau of Jingyang County are mainly classified as flowslide, slide and fall. Flowslide is the main type characteristic of high velocity, long runout and multi-stages. The steep relief composed of loose structured loess-old aged soil serials and the rise of groundwater table are the predominant conditions for landslides in the study area. To study loess mechanic poperties and loess landslides mechanisims, isotropically and anisotropically consolidated undrained compression(ICU and ACU) tests and constant-deviator-drained compression (CQD) tests were carried out on undisturbed samples. The results of undrained compression tests performed at the in-situ stress level show that the soils are of consistently strain-softening in the stress-strain relations and cause high excess pore pressure. The steady-state line and the potential region of instability are obtained from ICU and ACU test results. A necessary condition for liquefaction is that the soil state initially lies in or is brought into the potential instability region. In addition, a strong strain-softening model is also formed. CQD tests demonstrate that the mobilized friction angle is far less than the steady-state angle and that the soil experiences undrained contractive failure suddenly at very small strains when its stress path during drained loading tries to cross the potential instability region，thus validates the proposed instability region. Based on the location of the region of potential instability and the stress state of slope soil, a method of static liquefaction analysis is proposed for loess landslides caused by rise in groundwater table. Compared with other liquefaction analysis methods, this method overcomes the limitations inherent in conventional slope stability method and undrained brittleness index method. Triaxial tests composed of constant water content (CW) and wetting tests at constant deviator stress are performed on undisturbed unsaturated samples. The stress-strain relation of CW tests takes on strain-hardening behavior; The results of wetting tests at constant deviator stress designed to study the mechanics of failure of unsaturated loess caused by an increase in the degree of saturation (wetting) shows that a contractive failure occurs in the undisturbed samples. On the basis of the above triaxial test results, the initiation of static liquefaction is presented for long-runout loess landslides caused by rise in groundwater table, that is, the loess slope soil gradually transfer from unsaturated to saturated state under the infiltration of irrigation. A contractive failure occurs in the local region at very small strain by increasing the pore-water pressure at constant deviator stresses under drained conditons. It is the contractive failrue resulting from rise of pore pressure that leads to high excess pore pressure in the neighbour soil which reduces shear resistance of soil. The neighbour soils also fail due to the rapid increase in pore-water pressure. Thus a connected failure surface is developed quickly and a flowslide occurs. Based on the saturated-unsaturated seepage theory, transient seepage is computed using the finite element method on loess slope under groundwater table rise. Pore-water pressure distribution for every time step after irrigation are obtained. The phreatic surface in the slope increases with the groundwater table. Pore-water pressure distribution within 8m above the phreatic surface changes very quickly，but the water content and pore water pressure in the region ranging from 8m above the phreatic surface up to ground surface is almost not affected and the matric suction usually is kept at 100～120 kPa. Based on the results of laboratory tests and seepage flow analysis, the development process of loess landslide is modeled considering groundwater table rise. The shearing plastic zone first occurs at the slope toe where the soil is soaked for long term during rise in groundwater table. As irrigation continues, the shearing plastic zone gradually extends to the interior soils, with the results that the tensile plastic zone occurs at the slope crown. As time goes on, both the shearing plastic zone and tensile plastic zone continue to extend. Then a connected plastic zone is formed and fowslide occurs. In comparision to laboratory test results, the results of numerical simulation quite well verify the presented mechanism of static liquefaction of long-runout loess landslides caused by rise in groundwater table.

三峡库区巴东组泥灰岩溶蚀作用与岩体力学性质弱化研究

Abstract The karsrt erosion engineering geology became a highlight problem in recent years, in particularly, the karst erosion of marlite of Badong formation made the rock mechanics weaken in Three Gorges Reservoir area, which reduces the safety of slope. During the immigrant construction, many high slopes have been formed, whose instabilities problems pose serious threats to the safety of the people and properties. The accidents of the slope failure take place now and then. By testing, it has been found that the karst erosion pattern and dissolution rate of marlite are not weaker than that of the pure limestone. Furthermore, owning to the weathering and unloading, the karst erosion of the marlite will reach certain depth of the slope, which is named infiltrated karst erosion. The karst erosion made the rock mass quality of slope or foundation worse in a large scale. The karst erosion geological disasters, taken place or not, has become the main restrictive factors to the social stability and economic development. Thus the karst erosion process and mechanism of marlite of Badong formation are studied as the main content of this dissertation. The weakening characteristic of rock mass mechanics parameters are studied along with the rock mass structure deformation and failure processes in the course of the karst erosion. At first, the conditions and influencing factors of the karst erosion are analyzed in the investigative region, on the basis of different karst erosion phenomenon of the marlite and different failure modes of slope. Then via indoor the karst erosion tests, it is analyzed that the karst erosion will change the rock mass composition and its structure. Through test, the different karst erosion phenomena between micro and macro have been observed, and the karst erosion mechanism of the marlite has been summarized. Damage theory is introduced to explain the feature of dissolution pore and the law of crack propagation in the marlite. By microscope and the references data, it can be concluded that the karst erosion process can be divided into rock minerals damage and rock structural damage. And the percent of karst erosion volume is named damage factor, which can be used to describe the quantify karst erosion degree of marlite. Through test, the rock mechanical properties in the different period of karst erosion are studied. Based on the damage mechanics theory and the test result, the relation between the karst erosion degree of marlite and weakening degree of mechanical properties is summarized. By numerical simulations, the karst erosive rock mass mechanics is verified. The conclusion is drawn as below: to the rock mass of marlite, the karst erosion damage made mechanics parameters variation, the deformation modulus, cohesion, and inter friction angle reduce as the negative exponent with the increasing of the karst erosion volume, however, the Poisson ratio increases as the positive exponent with the karst erosion volume increasing. It should be noticed that the deduced formulations are limited to the test data and certain conditions. It is suitable to the rock mass parametric weakening process after the karst erosion of marlite in Three Gorges Reservoir area. Based on the failure types of marlite slope in the field, the karst erosion and weathering process of rock mass are analyzed. And the evolution law of deformation and failure of the marlite mass is studied. The main failure feature of the marlite slope is the karst erosive structure subsidence mode in Three Gorges Reservoir area. The karst erosive structure subsidence mode is explained as follows: the rock mass undergoes the synthetic influence, such as weathering, unloading, corrosion, and so on, many pores and cavities have been formed in the rock mass interior, the rock mass quality is worsen and the rock mass structure is changed, and then the inherent structure of rock mass is collapsed under its gravity, therefore, the failure mode of compaction and subsidence take place. Finally, two examples are used to verify the rock mass parameters in Three Gorges Reservoir area, and the relationship between the marlite slope stability and the time of karst erosion is proposed.

松辽盆地南部腰英台区块低渗透储层整体压裂改造技术研究

The Yaoyingtai Block is located within the northeastern Changling Depression of southern Songliao Basin, where the reservoir sandstones are petrophysically characterized by very low permeability, which results in the low success probability of artificial fracturing, and the low oil yield by water injection in the course of oil production. In order to improve the situations as stated above, this research aims to work out an integral fracturing technology and strategy applicable to the low permeable reservoirs in Yaoyingtai Block. Under the guidance of geological theory, reservoir engineering and technology, the subsurface occurrences of natural and hydraulic fractures in the reservoirs are expected to be delineated, and appropriate fracturing fluids and proppants are to be optimized, based on the data of drilling, well logging, laboratory and field experiments, and geological data. These approaches lay the basis of the integral fracturing technology suitable for the low permeable reservoir in the study area. Based on core sample test, in-situ stress analysis of well logging, and forward and inversion stress field modeling, as well as fluid dynamic analysis, the maximum in-situ stress field is unraveled to be extended nearly along the E-W direction (clustering along N85-135°E) as is demonstrated by the E-W trending tensional fractures. Hydraulic fractures are distributed approximately along the E-W direction as well. Faulting activities could have exerted obvious influences on the distribution of fractures, which were preferentially developed along fault zones. Based on reservoir sensitivity analysis, integrated with studies on rock mechanics, in-situ stress, natural fracture distribution and production in injection-production pilot area, the influences of primary fractures on fracturing operation are analyzed, and a diagnostic technology for primary fractures during depressurization is accordingly developed. An appropriate fracturing fluid (hydroxypropyl guar gum) and a proppant (Yixing ceramsite, with a moderate-density, 0.45-0.9mm in size) applicable to Qingshankou Formation reservoir are worked out through extensive optimization analysis. The fracturing fluid can decrease the damage to the oil reservoir, and the friction in fracturing operation, improving the effect of fracturing operation. Some problems, such as sand-out at early stage and low success rate of fracturing operations, have been effectively solved, through pre-fracturing formation evaluation, “suspension plug” fracturing, real-time monitoring and limited-flow fracturing. Through analysis of fracture-bearing tight reservoir with variable densities and dynamic analysis of influences of well patterns on fracturing by using numerical simulation, a fracturing operation scheme for the Qingshankou Formation reservoir is proposed here as being better to compress the short factures, rather than to compress the long fractures during hydraulic fracturing. It is suggested to adopt the 450m×150m inverted 9-spot well pattern in a diamond shape with wells placed parallel to fractures and a half fracture length of 60-75m.

天津滨海新区软土不同含砂量的强度特征研究

Based on the features of soft soil in Tianjing Coastal New Developing Area, this kind of soil with different content of sand was researched systematically, according to the indoor experiment, about its characteristics of strength and deformation. The main results are summarized in the following: Firstly, on the basis of geological engineering investigation, the systemic experiments about the physical characteristics were conducted. The test soil samples were taken from the gray and gray-yellow silty soft soil which was formatted by near-shore marine sediment and marine-continental interactive sediment. The original condition of the sample soil was in saturation and the basic indexes are: liquid limit36.1%, plastic limit 18.8%, plasticity index. Then, the condensation characteristics of the soft soil were analyzed through high-pressure consolidation tests. The results show that，in various loading serials, the coefficient of compressibility under P=100kPa and 200kPa are all larger than 0.5MPa-1. So the sample soil is a kind of high-compressibility soil. Secondly, triaxial strength of undisturbed soil and remoulded soil was researched by using triaxial test. The types of stress-strain curve of both undisturbed and remoulded soil are the stress stabilization and softening type, which show the specific plastic character. Furthermore, the cohesion and friction angle of undisturbed soil changes, when the ambient pressure is different, instead of a stable value for all time; the cohesion and friction angle of remoulded soil changes with the compactness and sand-carrying capacity which is wholly higher than undisturbed soil. At last, the stress-strain results of both undisturbed and remoulded soil were normalized by using the ambient pressure as the normalization factor. The results show that, there are all some normalization characters in both undisturbed and remoulded soil, however, the feature of normalization of undisturbed soil is worse than the remoulded ones. The main reason is that the undisturbed samples are worse in equality and the unavoidable disturb through the process of sampling and experiments will also make them can not put up good normalization. Therefore, it is feasible to normalize the soil in Tianjing Coastal New Developing Area with the ambient pressure as normalization factor.

急倾斜金属矿体开采岩体移动规律与变形趋势预测研究

Rockmass movement due to mining steep metallic ore body is a considerable question in the surface movement and deformation issue caused by underground mining. Research on coal mining induced rockmass movement and its prediction problem have been performed for a long-term, and have achieved great progress at home and abroad. However, the rockmass movement caused by mining steep metal mine is distinctivly different from coal seam mining.. Existing surface movement laws and deformation prediction methods are not applicable to the rockmass movement caused by mining steep metal mine. So far the home and abroad research to this theory is presently at an early stage, and there isn’t mature theory or practical prediction method, which made a great impact on production. In this paper, the research object—Jinchuan nickel mine, which is typical steep metal mine, characterized by complex geological conditions, developed faults, cracked rockmass, high geostress, and prominent engineering stability problems. In addition, backfill mining method is used in the mine, the features of rockmass movement caused by this mining method are also different from other mining methods. In this paper, the laws of rock mass movement, deformation and destroy mechanism, and its prediction were analyzed based on the collection of data, detailed in-sit engineering geology survey, ground movement monitoring by GPS, theoretical analysis and numerical simulation. According to the GPS monitoring of ground surface movement, ground subsidence basin with apparent asymmetry is developing, the influence scope is larger in the upper faulted block than in the lower faulted block, and the center of ground movement is moving along the upper faulted block direction with increasing depth of mining. During the past half and seven years, the largest settlement has amounted to 1287.5mm, and corresponding horizontal displacement has amounted to 664.6mm. On the ground surface, two fissure belts show a fast-growing trend of closure. To sum up, mining steep metal mine with backfill method also exist the same serious problem of rockmass movement hazards. Fault, as a low intensity zone in rockmass, when it located within the region of mining influence, the change of potential energy mainly consumed in fault deformation associated with rockmass structure surface friction, which is the essence of displacement and stress barrier effects characterized by fault rupture zone. when steep fault located in the tensile deformation region incurred by underground excavation, no matter excavation in hangingwall or in footwall of the fault, there will be additional tensile stress on the vertical fault plane and decrease in the shear strength, and always showing characteristics of normal fault slip, which is the main reason of fault escarpment appeared on the ground surface. The No.14 shaft deformation and failure is triggered by fault activation, which showed with sidewall move, rupture, and break down features as the main form of a concentrated expression of fault effects. The size and orientation of principal stress in surrounding rock changed regularly with mining; therefore, roadway deformation and damage at different stages have different characteristics and distribution models. During the process of mining, low-intensity weak structures surface always showed the most obvious reaction, accompany with surface normal stress decrease and shear strength bring down, to some extent, occurred with relative slide and deformation. Meanwhile, the impact of mining is a relatively long process, making the structure surface effect of roadway deformation and damage more prominent than others under the influence of mining. Roadway surrounding rockmass deformation caused by the change of strain energy density field after excavation mainly belongs to elastic deformation, and the correspondented damage mainly belongs to brittle rupture, in this circumstance, surrounding rockmass will not appear large deformation. The large deformation of surrounding rockmass can only be the deformation associated with structure surface friction or the plastic deformation of itself, which mainly caused by the permanent self-weigh volume force，and long-term effect of mining led to the durability of this deformation Good pitting fill effect and supporting effect of backfill, as well as the friction of rockmass structure surface lead to obvious macro-rockmass movement with long-lag characteristics. In addition, the loss of original intensity and new structure surface arisen increased flexibility in rockmass and fill deformation in structure surface, which made the time required for rockmass potential energy translate into deformation work associated with plastic deformation and structure surface friction consumed much, and to a large extent, eliminated the time needed to do those plastic work during repeated mining, all of which are the fundamental reason of rockmass movement aftereffect more significant than before. Mining steep deposits in high tectonic stress area and in gravity stress area have different movement laws and deformation mechanism. The steep deposit, when the vertical size of the mining areas is smaller than the horizontal size of the orebody, no matter mining in gravity stress area or in high tectonic stress area, they have similar features of ground movement with mining horizontal orebody; contrarily, there will appear double settlement centers on the ground surface under the condition of mining in high tectonic stress area, while there will always be a single center under the other condition. Meanwhile the ground movement lever, scale of mining influence area and macro features of ground movement, deformation and fracture are also different from mining in gravity stress area, and the fundamental reason lies in the impact of orientation of the maximum principal stress on rock movement features in in-site rock stress field. When mining thick and steep deposit, the ground surface movement and deformation characteristic curves are significantly different from excavating the horizontal ore bed and thin steep deposit. According to the features of rockmass movement rate, the development process of mining-induced rockmass movement is divided into three stages: raising stage, steadily stage and gradually decay stage. Considering the actual exploitation situation, GPS monitoring results and macro-characteristics of surface movement, the current subsidence pattern of Jinchuan No.2 mine is in the early stage of development. Based on analysis of surface movement rate, surface subsidence rate increase rapidly when mining in double lever at the same time, and reach its peak until the exploitation model ended. When double lever mining translate into single, production decreased, surface subsidence rate suddenly start to reduce and maintain a relatively low value, and the largest subsidence center will slowly move along with the hangingwall ore body direction with increasing depth of mining, at the same time, the scope and extent of subsidence in footwall ore body will begin magnify, and a sub-settlement center will appear on ground surface, accompanied with the development and closure trend of ground fissure, the surrounding rockmass of shaft and roadway will be confronted to more frequent and severe deformation and failure, and which will have a negative impact on the overall stability of No.2 mine mining. On the premise of continuity of rockmass movement, gray system model can be used in ground rockmass movement prediction for good results. Under the condition of backfill mining step by step, the loose effect of compact status of the hard, broken rockmass led to lower energy release rate, although surrounding rockmass has high elastic energy, loose and damage occurred in the horizontal ore body, which made the mining process safety without any large geological hazards. During the period of mining the horizontal ore body to end, in view of its special “residual support role”, there will be no large scale rockmass movement hazards. Since ground surface movement mainly related to the intensity of mining speed and backfill effect, on the premise of constant mining speed, during the period of mining the horizontal ore body to end, the rate of ground surface rockmass movement and deformation won’t have sudden change.

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.

滚石机理及滚石灾害评价研究

Rockfall is a geological evolution process involving detachment of blocks or boulders from a slope face, then their free falls, bouncing, rolling or sliding, and finally deposition near the toe of the slope. Many facts indicate that the rockfall can cause hazards to peoples, and it can be regarded as a geological hazard. A rockfall event may only involve a boulder or rock, and also several ones. When there are peoples, buildings, or other man-made establishments within the scope of rockfall trajectory, losses will be possibly induced in tenns of human lives or damages to these facilities. Researches into mechanism, kinematics, dynamics, hazard assessment, risk analysis, and mitigation measures of rockfalls are extremely necessary and important. Occurrence of rockfall is controlled by a lot of conditions, mainly including topographical, geomorphic, geological ones and triggering factors. The rockfall especially in mountainous areas, has different origins, and occurs to be frequent, unexpected, uncertain, in groups, periodic and sectional. The characterization and classification of the rockfalls not only increase knowledge about rockfall mechanism, but also can instruct mitigation of the hazards. In addition, stability of potential rockfalls have various sensitivity to different triggering factors and changes of geometrical conditions. Through theoretical analyses, laboratory experiments and field tests, the author presents some back-analysis methods for friction coefficients of sliding and rolling, and restitution coefficients. The used input data can be obtained economically and accurately in the field. Through deep studies on hazard assessment methods and analysis of factors influencing rockfall hazard, this paper presents a new assessment methodology consisting of preliminary assessment and detailed one. From the application in a 430 km long stretch of the Highway, which is located between Paksho and Nyingtri in Tibet, the methodology can be applicable for the rockfall hazard assessment in complex and difficult terrains. In addition, risk analyses along the stretch are conducted by computing the probability of encountering rockfalls and life losses resulting from rockfall impacts. Rockfall hazards may be mitigated by avoiding hazardous areas, clearness of dangerous rocks, reinforcement, obstructing the rockfalls, leading the rockfalls, warning and monitoring for rockfalls, etc. Seen from present remedial level of rockfall hazards, different mitigation measures, economical and effective buffering units, monitoring tecliniques and consciousness of environmental protection for rockfall mitigations should be further developed.

水库滑坡复活机理及其发展趋势预测研究

Various numbers of ancient landslides of various scales are frequently distributed on both banks of reservoirs, especially large reservoirs, both in China and abroad. During inundation and operation of theses reservoirs, some of the landslides are reactivated, which caused losses of people's lives and properties to various extents, some even disasters. Systematic studies are, however, very few on the reservoir-induced reactivation mechanism and development tendency prediction. Based on investigation of reservoir-induced reactivation phenomena of ancient landslides and relevant existing research problems, a systematic study is carried out on the field identification, induced reactivation mechanism, development tendency prediction, risk decision-making and treatment of reservoir-related ancient landslides, through analysis of large numbers of engineering geological investigation results, scientific experimental and research results, in combination with prevention and treatment practices of reservoir-related landslides both in China and abroad, and a series of research results have been obtained. 1. On the basis of study of the distribution features, genesis mechanism of ancient landslides on river banks, a set of scientific methods are summarized on field identification of ancient landslides, and a significant method named "lithologic sequence method" or "indicator layer method", is proposed, which is proved to be very useful. 2. A detail study is made on the reservoir-induced hydraulic effects and material mechanic effects (or softening effects) on the ancient landslide through model and case studies, which concludes that the magnitude and properties of reservoir-induced hydraulic effects are related to the shapes of sliding planes, water content and permeability of landslide materials and variation rate and magnitude of reservoir levels; the magnitude of material mechanic effects are related to the material composition (including mineral composition and grain size), natural water content and saturation state of sliding zones. Also a sensitive analysis is made on the factors that are related to the stabilities of the landslides, which indicate that the stability of a landslide is more sensitive to the groundwater head h_w in the slides and the inner friction angleψof sliding zones than others. 3. The joint inducing mechanism of rainfall and reservoir is also discussed in the paper through model analysis and case study, which proves that reservoir inundation increases firstly the sensitivity of a landslides to rainfall through reduction of its stability or cracking deformation which will increase the rainfall infiltration to the slide body, and then rainfall triggers reactivation or intensifies the reservoir-induced deformation of a landslide. 4. Based on rheologic test results of sliding zones of several reservoir-related ancient landslides, the rheologic characteristics of sliding zones have been discussed in detail and several typical rheologic models have been set up, which well explains the dynamic process of slide deformation. The response types to reservoir inundation and development tendency of reservoir -related ancient landslide are discussed in the paper based on field investigation results. And prediction methods for reservoir-related landslides have been studied based on the Mate-Synthetic principle of quantitative and qualitative analysis, as well as combination of computation and internal mechanism analysis, and a rheologic analytical method is proposed which is proved very useful for prediction of the landslide development tendency. 6. In disaster-prevention and treatment of reservoir-related landslides, risk decision-making has been proved very significant both in engineering and economics. Based on the practices in disaster-prevention and treatment of reservoir-related landslides both in China and abroad, the disaster-prevention risk decision-making for reservoir-related landslides has been proposed in terms of philosophy, methods and procedures, and well put into practice. A summary is also made through case study of the experiences of treatment of reservoir-related landslides both in China and abroad in terms of principle, methods and technical lines. 7 A detail study is made as a case study of the reactivated Maoping ancient landslide on the left bank of the Geheyan Reservoir on Qingjiang river in Hubei province, China, including its field identification features, reservoir-induced reactivation characteristics and mechanism, development tendency prediction and proposed counter measures based on risk analysis.