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 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...

B H E Settlement Bolt

Figure 6.44 Building Research Establishment settlement bolt system adjustment using the method of variation of coordinates (see section 6.3.1.4). This not only enables the most probable values of the positions to be arrived at, but also statistical data about the precision and reliability of the network to be determined. Furthermore, by interpreting these statistical indices and then the results of a network adjustment from two different epochs it is possible to evaluate the statistical...

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...

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...

Contributors

Peter Ackers, MSc(Eng), CEng, FICE, MIWEM, MASCE Hydraulics consultant The late J Allen, DSc, LLD, FICE, FRSE Emeritus Professor, University of Aberdeen Manager, Underwater Engineering Group, London SCC Bate, CBE, BSc(Eng), PhD, CEng, FICE, FIStructE Formerly at the Building Research Establishment, and later consultant to Harry Stanger Ltd Keith M Brook, BSc, CEng, FICE, FIHT Wimpey Laboratories Ltd Staff of Central Electricity Generating Board Generation Development and Construction Division...

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...

Info

A variety of methods is available to improve the bearing capacity and decrease the compressibility of natural soils and manmade fills on site. They include preloading, vibro or dynamic compaction and the use of stone columns. Improvement of soils by preloading is one of the techniques. The method is most applicable to loose sands, silts and waste materials. The types of work for which the method is most appropriate are those in which column loads will be relatively low, such as for embankments,...

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,...

Lwl

Passive earth pressure (divided by factor of safety) Passive earth pressure (divided by factor of safety) Figure 9.21 Dimensions and forces in anchored bulkhead calculation. Earth pressure diagrams illustrated are for homogeneous cohesionless soil. No pressures from surcharge loads have been shown 9.4.6.1 Forces acting on faces of bulkhead The active and passive pressures are first calculated. The active pressure calculations must allow for the maximum possible unbalanced water pressure and for...

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...

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,...

Flow Chart For Slope Stability In

Schmidt Hammer Chart

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...

Seepage and flow nets

Flow Lines And Equipotential Lines

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 y Sheet pile wall A Side b F idation pit y Sheet pile wall A Side b F idation pit bj ' h h h As J1 ' gt Rolled fill dam of fine, clean sand Water surface - S T C' Graded filter Flow Equipotential lines i i i ' ' j i i Figure 9.31 Examples of flow...

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...