Injection processes grouting

It is sometimes possible to change the properties of the ground encountered by injecting materials of various sorts into the voids of the soil. These changes include (1) reduction in permeability (2) increase in strength and (3) decrease in compressibility, or a combination of these. A major use is for filling voids in mine workings and karstic limestone. Cases in which the reduction in permeability is important include (1) the formation of grouted cutoffs under dams (2) grouting fissured rocks...

Strength tests

A9.1.4.1 Californian bearing ratio (CBR) The Californian bearing ratio (CBR) test was developed in 1938 to evaluate Californian highway subgrade strengths and became the basis for the design of road and airfield pavements throughout the world. It is used both in situ and on prepared samples in the laboratory, but is limited to materials of particle sizes up to a maximum of 20 mm. The test determines the relationship between force and penetration when a cylindrical plunger 1935 mm2 in...

Appendix Ground improvement

There are numerous cases in which the properties of naturally occurring soil or fill material can be improved or changed to help solve engineering problems arising either in temporary or permanent works. The methods of ground improvement cover a wide range of techniques - often referred to as geotechnical processes - and include compaction, moisture control, stabiliza tion, grouting and reinforcement. Reference should also be made to the use of geotextiles for reinforcement, separation and...

Appendix Laboratory testing of soils

This appendix gives a brief outline of some of the main laboratory tests required to classify individual soils and to indicate their compaction and strength characteristics. In order to obtain reliable results, it is essential to follow the recommendations in Chapter 11 with regard to sampling and then to follow closely the practices recommended in the appropriate standards for sample preparation, testing and reporting. The outline in this section is based on British Standard BS 1377 1975 but...

Appendix Pile capacities

Piles are used to transfer foundation loads to a deeper stratum when the surface soils are too weak or too compressible to carry the load without excessive settlement. Details of pile types and their design and use are given in Chapter 17. The reader's attention is drawn to the references in Chapter 17 for further information, particularly to BS 8004, Tomlinson61-62 and to series of CIRIA PSA piling guides. In this appendix, methods are given for estimating the carrying capacity of piles in...

Basic geology

Rock is strictly defined in geology as any natural solid portion of the Earth's crust which has recognizable appearance and composition. Some rocks are not necessarily hard, and in discussion a geologist may call peat or clay a rock as he would granite or limestone. There are three major classes of rocks (1) Sedimentary rocks formed by the deposition of material at the Earth's crust, e.g. sandstone, clay. (2) Igneous rocks formed from molten rock magma solidifying either at the Earth's surface...

Characterizing rock mass properties

Rocks may be classified using geological names only, but this approach can mislead because the names are sometimes general and depend on properties that are of little engineering significance. For example, 'granite' can be a crumbly sand or a broken rubble rather than the monolithic material implied by the name. Shales, mudstone and limestone can also exhibit an extremely broad range of engineering properties. On the other hand, there are over 2000 igneous rock names in existence, reflecting...

Computers in surveying

Computers have, throughout their development, been extremely important in the fields of surveying and mapping. Initially, their use was almost exclusively restricted to the 'number crunching' requirements of large organizations carrying out geodetic computations or the adjustment of major control frameworks. Operations of this type were carried out on large mainframe computers in batch mode. Whilst slow and cumbersome to operate by modern computing standards, these early computers offered...

Data acquisition

Data can be acquired for remote sensing from a variety of aerial platforms, although fixed-wing aircraft and unmanned orbiting satellites are the most common. Both have specific and complementary advantages. Aircraft, for example, enable small localized phenomena to be investigated at high levels of resolution, whereas satellites enable wide synoptic views of the terrain to be obtained, often on a repeatable basis, but at much lower resolution. Vertical panchromatic aerial photography taken...

Dsvp deydPf y j g y de

From Figure 1.32, < J r dx j 2 fix) dx 1.5.5.2 Polar coordinates From Figure 1.33, dA p2dd Therefore A p2d9 J (0) 2< (Note. For curve cutting x axis, equate fix) to zero, find values of x for v 0 and integrate between these values for the area cut off by the x axis.) When the area lies above and below the x axis integrate the positive and negative areas separately and add algebraically. Where the area does not extend to the x axis in the case of cartesian coordinates, or to the origin in...

Engineering geology environments

A geological environment is the sum total of the external conditions which (nay act upon the situation. For example, a 'shallow marine environment' is all the conditions acting offshore which control the formation of deposits on the sea bed the water temperature, light, current action, biological agencies, source of sediment, sea bed chemistry and so on. The concept of geological environment forms a suitable basis to study systematically the engineering geology of the deposits formed in or...

Geological information

Although geological information is available in the form of maps and in written texts and both published and unpublished data may have to be acquired, Military engineering, vol. XV36 suggests the following. Most countries now publish geological maps with supporting literature. This basic literature, which is usually readily available and understandable to a non-geologist, may take the form of a memoir, dealing with the geology of one map sheet or area (or with one aspect of the geology of...

P I P

3.4.3 Assembly of structure stiffness matrix The stiffness method involves the solution of a set of linear simultaneous equations, representing equilibrium conditions, which may be expressed in the form Equation (3.31) is similar in form to Equation (3.23) with the important difference that now we are concerned with a multiple degree of freedom system as distinct from a single unknown displacement. K is the structure stiffness matrix, r is a matrix of nodal displacements and R a matrix of...

Info

Figure 8.25 Examples of particle-size curves of some glacial soils and a London Clay for comparison Figure 8.25 Examples of particle-size curves of some glacial soils and a London Clay for comparison fluvioglacial deposits up to 30 m in thickness. In other areas they exist as thin lenses of limited lateral extent included between layers of till or peat. Deposits of fluvioglacial soils may also occur in river valleys (valley trains) that once served as drainage outlets for glacial meltwater or...

Conic Sections Ellipse Tangent Subnormal Normal Length Property

Figure 1.36 Properties of a conic section Referring to Figure 1.37, F F2 and the foci D,D,, D2D2 the directrices. FVV, Fyv, FVV, F F OFl OF2 e S,V, S,V, S,V, MS, MS, OV, OV2 V,V Let OV, the semi-major axis a and OE the semi-minor axis b, then OF, OF, ae and OS, OS, - also F,P a e.x F2P + i Y F,P+ F,P 2a F,E cOS, a (OE)2 b2 (F,E)2- (OF,)2 a2(I - e2), Hence, as OM x and PM y we have the following. Figure 1.36 Properties of a conic section Figure 1.37 Ellipse in cartesian coordinates Figure 1.37...

Introduction

Geological Joints

10.1 The scope of rock mechanics and rock engineering Rock mechanics is a term for science and engineering applied to rock masses. As such, the term has relevance in numerous fields such as the recovery of hydrocarbons in rock reservoirs, development of geothermal energy resources, studies of the Earth's crust, seismicity studies, as well as mining and civil engineering. The area of activity restricted to construction works which require or essentially comprise excavation into the surface of,...

O

Super 120 90 Zeiss (Ober.) RMK A Normal 60 300 Zeiss (Ober.) RMK A Figure 7.8 Variation in ground coverage of normal, wide and superwide angle cameras Figure 7.8 Variation in ground coverage of normal, wide and superwide angle cameras angle (SWA) lens is its greater ground coverage for a given flying height. This is particularly important since it not only reduces the number of photographs required to cover an area, but also reduces the number of control points which are required for...

Plastics and rubbers Terminology

Standard definitions of terms relating to plastics (ASTM D883) includes the following. Polymer A substance consisting of molecules characterized by the repetition (neglecting ends, branch junctions and other minor irregularities) of one or more types of monomelic units. Plastic(s) A material that contains as an essential ingredient one or more organic polymeric substances of large molecular weight, is solid in its finished state and, at some stage in its manufacture or processing into finished...

Principles of photogrammetry

Since measurements may be taken from both air and ground images (normally photographs) two separate branches of the discipline are generally recognized aerial and close range (or terrestrial) photogrammetry. Aerial photogrammetry is a well-established technique in civil engineering for the production of topographic maps. Aerial photographs produced for such purposes can be obtained either with the optical axis of the camera pointing, nominally, vertically downwards so producing vertical aerial...

References

W. (1954) 'The pore pressure coefficients A and B Geotechnique, 4, 143. 2 Bishop, A. W. and Henkel, D. J. (1957) The measurement of soil properties in the triaxial test. Edward Arnold, London. 3 Taylor, D. W. (1948) Fundamentals of soil mechanics. Wiley, New York. 4 Terzaghi, K. and Peck, R. B. (1967) Soil mechanics in engineering practice. Wiley, New York. 5 Loudon, A. G. (1952) 'The computation of permeability from simple soil tests', Geotechnique, 3, 165. 6 Gibson, R. E. and...

The basics of soil behaviour

In engineering terms, soil is the generally softer, weaker and more weathered material overlying rock. All soils consist of solid particles assembled in a relatively loose packing. The voids between the particles may be filled completely with water (fully saturated soils) or may be partly filled with water and partly with air (partly saturated soils). Soil and rock materials can, very simply, be divided into the groups shown in Table 9.1. The primary engineering problems which we attempt to...

The stability of slopes

The analysis of slopes is important because of the dangers to both structures and life that can be caused by two types of problem (1) Where construction or excavation causes stress changes in the soil which lead to failure in previously stable ground (the so-called 'first-time slide'). (2) Where construction or excavation reactivates movement on a pre-existing shear surface in the soil, usually part of an ancient and pre-existing landslide. As with other areas of soil mechanics, an important...

The use of photogrammetry in civil engineering

The use of aerial survey is generally considered to be the standard method of producing a topographic map or plan at scales smaller than 1 500. For scales greater than 1 500, ground survey would almost invariably be used. The basic sequence of operations required for the production of a topographic map is shown by the flow diagram in Figure 7.17. The major air survey companies will have the equipment and manpower to carry out all the stages indicated but smaller concerns might, for example,...

Seepage and flow nets

A flow net is a graphical representation of the pattern of the seepage or flow of water through a permeable soil. It is possible, by means of a flow net, to calculate the hydrostatic uplift on a structure such as a dam or barrage, the amount of seepage It is common practice to start the analysis by assuming a uniform distribution off(x) (say (.*) 1.0) across the slip. Some authors have indicated that variations in the shape of the f(x) distribution have little effect on the factor of safety...

Flow Chart For Slope Stability In

Figure 10.13 An illustration of the size-dependence of shear stress-deformation behaviour for nonplanar joints. (After Bandis, Lumsden and Barton (1981) 'Experimental studies of scale effects on the shear behaviour of rock joints'. Int. J. Rock Mech. Min. Sci., 18) The analysis of a rock structure should not start without first preparing a complete statement of the factors involved. These usually include the geometry and intended purpose of the structure together with the main elements of the...

Standards and codes of practice referred to in Chapter

BS 12 1978 Specification for ordinary and rapid-hardening Portland cement. BS 146 1973 Part 2 Specification for Portland blast-furnace cement. BS 812 1984 Part 101 Guide to sampling and testing aggregates. BS 877 1973 1977 Part 2 Specification for foamed or expanded blast-furnace slag lightweight aggregate for concrete. BS 882 1983 Specification for aggregates from natural sources for concrete. BS 915 1972 1983 Part 2 Specification for high alumina cement. BS 1014 1975 1986 Specification for...