《工程地质专业英语》

《工程地质专业英语》教学大纲课程代码：课程名称：工程地质专业英语学时安排：总学时36学分：2适合专业：工程地质先修课程：《大学英语》，《工程地质学》，《工程岩土学》等教材：〈工程地质专业英语〉郑孝玉编，吉林大学校内讲义，2005，7参考书：编写人：郑孝玉➢教学目的和要求工程地质专业英语是工程地质专业4年级学生的选修课，是在学生学习和掌握了基础理论课，专业课及大学英语之基础上为培养和提高学生专业英语能力而设置的。

通过讲授和与学生交流为他们灌输一些相关专业词汇，表述方式及科学文献的翻译、课程写作技巧和规范等。

为将来学习和工作储备一些相关知识。

➢课程内容概要1．本课程教学内容●The Engineering Properties of Rocks1）rock index propertiesCertain index properties of rocks are of particular importance to the engineering, which are defined below.Specific gravity (G s and G b). G b is the specific gravity of the solid mineral material of the rock by itself. G b is the specific gravity of the complete rock, grain plus voids, with the voids empty except for air. Both are defined as a weight per unit volume.Saturation moisture content (i s). This is the total amount of water present in a rock with the voids full. The ratio of weight of water to dry weight of rock sample, expressed as a percentage, is the saturation moisture content (i s).Moisture content (W). This is the amount of water normally present in the voids of a rock , again expressed as a percentage (see i s) above. Rocks are rarely saturated with water, thus in normal circumstances w is less than is.Porosity (n). This is the ratio of volume of voids in a rock total volume of the sample. It is expressedas a percentage; 10% average, 5% is low and more than 15% is high.The factors that control the porosity of terrigenous sedimentary rocks and soils are as follows:(a)The degree of cementation(b)The sorting of the sediment(c)The packing of the grains(d)The shape of the grainsWater-yielding capacity. Not all of the water in a rock can be removed from it by flow under the force of gravity. Some is held as a film on the surface of the grains by capillary forces.Permeability(k). This is a measure of the fluid conductivity of the rock for a given hydraulic gradient.2）basic characteristics of soils2.1 the nature of soilsThe destructive process in the formation of soil from rock may be either physical or chemical. The physical process may be erosion by the action of wind, water or glaciers, or disintegration caused by alternate freezing and thawing m in cracks in the rock.The chemical process results in changes in the mineral form of the parent rock due to the action of water (especially if it contains traces of acid or alkali), oxygen and carbon dioxide. Chemical weathering results in the formation of groups of crystalline particles of colloidal size (<0.002 mm) known as the clay minerals.Particle sizes in soils can vary from over 100 mm to less than 0.001 mm. Most types of soil consist of a graded mixture of particles from two or more size ranges. All clay size particles are not necessarily clay mineral particles: the finest rock flour particles may be of clay size. If clay mineral particles are present they usually exert a considerable influence on the properties of a soil, an influence out of all proportion to their percentage by weight in the soil.2.2 particle size analysisThe particle size analysis of a soil sample involves determining the percentage by weight of particles within the different size ranges. The particle size distribution of a coarse-grained soil can be determined by the method of sieving. The soil sample is passed through a series of standard test sieves having successively smaller mesh sizes. The weight of soil retained in each sieve is determined and the cumulative percentage by weight passing each sieve is calculated. If fine-grained particles are present in the soil, the sample should be treated with a flocculating agent and washed through the sieves.The particle size distribution of a soil is presented as a curve on a semi-logarithmic plot, the ordinates being the percentage by weight of particles smaller than the size given by the abscissa. The flatter the distribution curve the larger the range of particle sizes in the soil; the steeper the curve the smaller the size range. A coarse-grained soil is described as well graded if there is no excess of particles in any size range and if no intermediate sizes are lacking. In general a well graded soil is represented by a smooth, concave distribution curve. A coarse-grained soil is described as poorly graded (a)if particles of both large and small sizes are present but with a relatively low proportion of particles of intermediate size (a gap-graded soil). Particle size is represented on a logarithmic scale so that two soils having the same degree of uniformity are represented by curves of the same shape regardless of their positions on the particle size distribution plot. The particle size corresponding to any specified value on the percentagesmaller scale can be read from the particle size distribution plot.2.3 plasticity of fine-grained soilsPlasticity is an important characteristic in the case of fine-grained soils, the term plasticity describing the ability of a soil to undergo unrecoverable deformation at constant volume without cracking or crumbling. Plasticity is due to the presence of clay minerals or organic material.Most fine-grained soils exist naturally in the plastic state. The upper and lower limits of therange of water content over which a soil exhibits plastic behaviour are defined as the liquid limit (LL or w L) and the plastic limit (PL or w P) respectively.2.4 soil compactionCompaction is the process of increasing the density of a soil by packing the particles closer together with a reduction in the volume of air: there is no significant change in the volume of water in the soil. In the construction of fills and embankments, loose soil is placed layers ranging between 75 mm and 450 mm in thickness, each layer being compacted to a specified standard by means of rollers, vibrators or rammers. In general the higher the degree of compaction the higher will be the shear strength and the lower will be the compressibility of the soil.The degree of compaction of a soil is measured in terms of dry density, i.e. the mass of solids only per unit volume of soil.The dry density of a given soil after compaction depends on the water content and the energy supplied by the compaction equipment (referred to as the compactive effort).The compaction characteristics of a soil can be assessed by means of standard laboratory tests. After compaction using one of the three standard methods, the bulk density and water content of the soil are determined and the dry density calculated. For a given soil the process is repeated at least five times, the water content of the sample being increased each time. At low values of water content most soils tend to be stiff and are difficult to compact. As the water content is increased the soil becomes more workable, facilitating compaction and resulting in higher dry densities. At high water contents, however, the dry density decreases with increasing water content, an increasing proportion of the soil volume being occupied by water.In Situ Testing1. penetrometersPenetrometer test evolved from the need to acquire data on subsurface soils which could not be obtained by other means. Basically a penetrometer consists of a conical point attached to a drive rod which is forced into the ground either by hammer blows or by jacking. Hence two types of penetrometer tests are recognized, the dynamic and the static. Both methods measure the resistance to penetration offered by the soil at any particular depth. Penetration of the cone forces the soil aside, creating a complex shear failure and thus provides an indirect measure of the in situ shear strength of the soil.Dynamic penetrometers were originally designed to determine the relative density of cohesionless soils but their use has been extended to include the design of pile foundations by determining the load and the required embedment of piles into the bearing strata.2．shear vane testBecause soft clays, may suffer disturbance when sampled and therefore give unreliable results whentested for strength in the laboratory, a vane test is often used to measure the in situ undrained shear strength. Vane tests can be used in clays which have a consistency varying from very soft to firm.3．plate load and jacking testsLoading tests can be carried out on loading plates. However, just because the ground immediately beneath a plate is capable of carrying a heavy load without excessive settlement, this does not necessarily mean that the ground will carry the proposed structural load. This is especially the case where a weaker horizon occurs at depth but is still within the influence of the bulb of pressure which will be generated by the structure.4．Pressure testsHydrostatic pressure chambers are used to measure the reaction of a rock mass to stress over large areas, giving values of Young’s modulus, elastic recovery, inelastic deformation and creep. The results are used to evaluate the behaviour of dam foundations and related strain distribution in the structure and to help estimate the behaviour of pressure tunnel linings. Hydrostatic chambers cover a much larger surface area than other test methods and so provide better results of mass behaviour. However, because of their cost these tests are used sparingly. A dilatometer can be used in a borehole to obtain data relating to the deformability of a rock mass. These instruments range up to about 300 mm in diameter and over 1 m in length and can exert pressures of up to 20 MN/m2 on the borehole walls.5．In situ shear testIn an in situ shear test a block of rock is sheared from the rock surface whilst a horizontal jack exerts a vertical load. It is advantageous to make the tests inside galleries, where reactions for the jacks are readily available. The tests are performed at various normal loads and give an estimate of the angle of shearing resistance and cohesion of the rock. In situ shear tests are usually performed on blocks, 700 ×700 mm, cut in the rock. These tests can be made on the same rock where it shows different degrees of alteration and along different directions according to the discontinuity pattern. The factor of safety against strain due to sliding may depend on a limited zone and it is therefore essential to find and investigate the weakest zones. It is sometimes difficult to obtain sufficiently undisturbed, as in the case of shales, to perform tests. This is also the case when the rocks are affected by residual stresses.Consolidation TheoryConsolidation is the gradual reduction in volume of a fully saturated soil of low permeability due to drainage of some of the pore water, the process continuing until the excess pore water pressure set up by an increase in total stress has completely dissipated: the simplest case is that of one-dimensional consolidation, in which a condition of zero lateral strain is implicit. The process of swelling, the reverse of consolidation, is the gradual increase in volume of a soil under negative excess pore water pressure. 1．the oedometer testThe characteristics of a soil during one-dimensional consolidation or swelling can be determined by means of the oedometer test. The test procedure has been standardized in Standards which specifies that the oedometer shall be of the fixed ring type. The void ratio at the end of each increment period can be calculated from the dial gauge readings and either the water content or dry weight of the specimen at the end of the test.2．compressibility characteristicsTypical plots of void ratio (e) after consolidation, against effective stress (σ/) for a saturated clay are shown that an initial compression followed by expansion and recompression. The shapes of the curves are related to the stress history of the clay.The compressibility of the clay can be represented by one of the following coefficients.The coefficient of volume compressibility (m v ), The compression index (C c ).3. Preconsolidation pressureWhenever possible the preconsolidation pressure for an overconsolidated clay should not be exceeded in construction. Compression will not usually be great if the effective vertical stress remains below /c σ:only if /c σis exceeded will compression be large.4. 1-D consolidation settlement5. degree of consolidation6. Terzaghi ’s theory of one-dimensional consolidationThe assumptions made in the theory are:1. The soil is homogenous.2. The soil is fully saturated.3. The solid particles and water are incompressible.4. Compression and flow are one-dimensional (vertical).5. Strains are small.6. Darcy ’s law is valid at all hydraulic gradients.7. The coefficient of permeability and the coefficient of volume compressibility remain constant throughout the process.8. There is a unique relationship, independent of time, between void ratio and effective stress.7. Second compressionSecondary compression is thought to be due to the gradual readjustment of the lay particles into a more stable configuration following the structural disturbance caused by the decrease in void ratio, especially if the clay is laterally confined. An additional factor is the gradual lateral displacements which take place in thick clay layers subjected to shear stresses. The rate of secondary compression is thought to be controlled by the highly viscous film of adsorbed water surrounding the clay mineral particles in the soil..Bearing CapacityIn order to avoid shear failure or substantial shear deformation of the ground, the foundation pressures used in design should have an adequate factor of safety when compared with the ultimate bearing capacity of the foundation. The ultimate bearing capacity is the value of the loading intensity which causes the ground to fail suddenly in shear. If this is to be avoided then a factor of safety must be applied to the ultimate bearing capacity, the value obtained being the maximum safe bearing capacity.1. stress distribution in soilA reasonable approximation of how stress is distributed in soil uponloading can be obtained by assuming that the soil behaves in an elastic manner as if it was a homogenous material.2. Foundation failureThere are usually three stages in the development of a foundation failure.The weight of the material in the passive zones resists the lifting forces and provides the reaction through the other two zones which counteract downward motion of the foundation structure. Thus the bearing capacity is a function of the resistance to uplift of the passive zone. A surcharge placed on the passive zone or increasing the depth of the foundation therefore increase the bearing capacity.3. bearing capacity factorsA number of bearing capacity factors are used to determined the influence of the various characteristics of a soil and formation structure on the ultimate bearing capacity.4. contact pressureThe pressure acting between the bottom of a foundation structure and the soil is the contact pressure. The assumption that a uniformly loaded foundation structure transmits the load uniformly so that the ground is uniformly stressed is by on means valid. In fact, of course, the clay yields slightly and so reduces the stress at the edges. As the load is increased more and more local yielding of the ground material takes place until, then the loading is close to that which would cause failure, the distribution is probably very nearly uniform. Therefore at working loads a uniformly loaded foundation structure on clay imposes a widely varying contact pressure.5. allowable contact pressure for rock massesIf the rock mass contains few defects the allowable contact pressure at the surface may be taken conservatively as the unconfined compressive strength of the intact rock. Most rock masses, however, are affected by joints or weathering which may significantly affect their strength and engineering behaviour.●The stability of slopes1 the stability of slopes in soilsThe stability of slopes is critical factor in open excavation. This stability is usually expressed in terms of factor of safety (F), the design of potential stability increasing as the value of F increases above unity. A soil mass under given loads should have an adequate factor of safety will respect to shear failure, and deformation under given loads should not exceed certain tolerable limits.There are several methods available for analysis of the stability of slopes in soils. Most of theses may be classed as limit equilibrium methods in which the basic assumption is that coulomb’s failure criterion is satisfied along the assumed path of failure.1.1 analysis of stability in cohesive soil1.2 the Swedish method slices2 the stability of slopes in rocksThe design for a slope excavated in rock necessitates a well planned site investigation, indeed no design can be better than the quality of the geological input data. Such a site investigation must obtain as much information as possible on the character of the discontinuities within the rock mass in question, since the stability of a rock mass is frequently dependent upon the nature of the discontinuities. Information relating to the spatial relationships between discontinuities affords some indication of the modes of failure which may occur and information relating to the shear strength of the rock mass, or more particularly the shear strength along discontinuities, is required for use in the stability analysis. Furthermore data should be collected from all newly excavated faces in order to confirm or amend the original assumption made during design and, if necessary, to provide a basis for re-design.2.1 factors influencing rock slope stability2.2 types of failure in rock slopes●Methods of slope control and stabilizationIt is rarely economical to design a rock slope so that no subsequent rock falls occur, indeed many roads in rough terrain could not be constructed with the finance available without accepting some such risk. Therefore except there absolute security is essential, slopes should be designed to allow small falls ofrock under controlled conditions. For an economical design, about 10% of the slope area may require some treatment at a later date. Subsequent slope treatment may take the form of a reduction in the overall slope angle so as to increase the factor of safety. Obviously care must be taken to avoid damaging the slope when it is being trimmed by further blasting. Care also should be taken to maintain a constant slope line.1 reinforcement of slopesRock bolts may be used as reinforcement to enhance the stability of slopes excavated in jointed rock masses. They provide additional strength on critical planes of weakness within the rock mass.Reinforced earth walls are constructed by erecting a thin front skin at the face of the wall whilst at the same time the earth is placed. Strips of steel are fixed to the facing skin at regular intervals. They can be rapidly erected but only serve to support shallow translation slides. Gabions consists of strong wire mesh surrounding placed stones which are built to a given height. They provide a stable structure pervious to water.2 drainage of slopesDrainage is the most generally applicable method for improving the stability of slopes for the corrective treatment of slides, regardless of type, since it reduces the effectiveness of the principal causes of instability, namely, excess pore water pressure. In rock masses ground water also tends to reduce the shear strength along discontinuities. Moreover drainage is the only economic way of dealing with slides involving the movement of several million cubic metres.●Underground cavern1 location of underground cavernThe site investigation for an underground cavern has to locate a sufficiently large mass of sound rock in which the cavern can be excavated. Because caverns usually are located at appearance of weathering and consequently the chief considerations are rock quality, geological structure and ground water conditions. The orientation of an underground cavern is usually based on an analysis of the area and, where relevant, also on the basis of the stress distribution. It usually is considered necessary to avoid and orientation whereby the long axis is parallel to steeply inclined major joint sets.2 stability of underground caverns3 influence of joins4 excavation of underground caverns●Types of foundation structuresFootingsRafsPiersPiles●Dewatering●Some of the worst conditions are met in excavation which have to be taken below the water table. In such cases the water level must be lowered by dewatering. The method adopted for dewatering an excavation depends upon the permeability of the soil and its variation within the stratal sequence, the depth of base level below the water table, piezometric conditions in underlying horizons, the method ofproviding support to the sides of the excavation and of safeguarding neighbouring structures.●Methods of ground treatment1 grounting2 vibroflotation or vibrocompaction3 dynamic compaction●Geological factors in roof behaviorApart from the presence of high stress levels in relation to rock strength, strata behaviour in the roof of an underground mine is affected by a number of detailed geological features in the actual beds concerned among which the more significant factors are discussed below.1 presence of weak or unconsolidated materials2 deteroration with exposure3 bedding-plane discontinuities4 washout structures5 joint and fault pattern2．学生学习本课程的基本要求了解和掌握工程地质有关的专业词汇，规范的英语表达方式；通过教学是学生基本借助工具书可以流利阅读，翻译专业英语。