1. Our Earth

The universe is over 10 billion years old. Our solar system comprising the sun and nine planets including earth formed 4.6 billion years ago. The earth has a mass of 5976 million million million tonnes and an equatorial circumference of 40,075 kilometres. The earth’s crust is about 6 to 64 km thick under oceans and mountains, respectively. The crust floats on a semi molten mantle and a molten core. Oxygen is the most adundant element at 47 percent. Oceans cover 71 percent of the earth. Continental drift progresses slowly causing earthquakes, volcanoes and mountains. Rocks have mixtures of minerals. The three main rock groups are igneous, sedimentary and metamorphic. Weathering breaks rock into particles ranging in size from boulders, cobbles, gravel, sand, silt to clay. Climate significantly affects soils and vegetation.


A geological site characterization is inadequate for quantitative design and construction purposes. A geological survey of the area indicates the type and pattern of subsurface strata to be expected.  Topographic features may correlate to glacial deposits. A geologic survey of the project site identifies the types of overburden soil and bedrock strata which are likely to be encountered. The geoengineering consultant can carry out a study of the regional geology and the local geology in order to plan and execute a major site exploration program.


The ever changing migration of atmospheric, surface and ground water is a complex interdependent system called collectively the hydrologic cycle. Although the hydrogeologist is concerned chiefly with groundwater, all aspects of the hydrologic cycle must be understood before an accurate characterization of the subsurface portion of the cycle can be achieved.



For the owner, designer, contractor or regulatory agency engaged in the planning, design, construction, operation or maintenance of civil works and mining projects, the properties of soil, rock, groundwater and contaminants, and their impact on earthworks, structures and humans is of primary importance. These earth engineering properties include structure, strength, deformation, permeability, surface water and groundwater interaction, geochemistry and seismicity.


The subsurface investigation is the first and most important step for all earthworks and structures. A drilling and sampling investigation should be carried out for all earthworks and structures, even modest ones, (i) before design is undertaken, or (ii) before the approval of a regulatory body is sought, and (iii) before construction tendering commences.


Soil is that portion of the earth’s crust, which is fragmentary, rock dust or such that some individual particles of a dried sample may be readily separated by agitation in water; it includes boulders, cobbles, gravel, sand, silt, clay and organic matter. Soils are identified and classified according to their particle size and distribution for coarse grained soils, and their plasticity for fine grained soils, which are based on soil laboratory testing, and the Unified Soil Classification System.


Rocks and minerals are fundamental introductions to the study of all natural history, leading to a greater appreciation of nature and earth engineering. Rock types are classified into three major groups: igneous, sedimentary and metamorphic, and then subdivided into several divisions.


Groundwater is the subsurface water that occurs beneath the water table in soils, rocks and geologic formations that are fully saturated. For purposes of groundwater supply or groundwater control our traditional focus is on shallow, saturated, groundwater flow; but on a broader sense, it also encompasses the near surface, unsaturated, soil-moisture regime that plays an important role in the hydrologic cycle; and it includes the much deeper, saturated regimes that have an important influence on geologic processes.


Deep excavations may be sloped open cut excavations or horizontally braced excavations. In most instances, problems arise during trench excavation work due to (i) unfavourable soil and groundwater conditions, (ii) excavation procedures, (iii) foundation and bedding requirements, or (iv) backfill compaction requirements.


Earthworks includes shallow and deep excavations, and soil backfill compaction.  Soil compaction is the process of forcing soil particles closer together. This is accomplished by eliminating, or at least reducing, the air voids in a given volume of soil. Soil moisture content, compactive effort, ambient temperature and grain size characteristics are important contributing factors.


Geosynthetics may be referred to as geotextiles or filter fabrics when designed as a permeable system providing separation, filtration, drainage and/or reinforcement for the given soil and groundwater conditions.

Geosynthetics may be produced as impermeable liner systems, used as a barrier and/or liner protection for explosive gases and contaminant migration.


The design of a shallow foundation system normally requires that both bearing capacity and settlement be checked.  Structural distress from soil settlement is often evidenced by cracking, distortion or openings. A deep foundation provides support for a structure by transferring loads either by end-bearing to a soil or rock at considerable depth below the structure, or by adhesion or friction, or both, in the soil or rock in which it is placed.


For several years the public has been taking a greater interest in the effects of large scale projects involving municipal development, highways, airports, water and sewage treatment plants, pipelines, river diversions, industrial and petrochemical plants, mining and forestry facilities, landfills and spills. In many instances the public has objected to property rights. There is growing public support and enforceable legislation in developing jurisdictions for the belief that environmental assessment is an essential component of all stages of project planning, implementation, operation, and site decommissioning.


The goal of remedial investigation and feasibility studies, environmental site remediation, and hazardous waste cleanup projects is to obtain sufficient site information to consider select practicable remedial alternatives. Contaminants may be separated into five contaminant groups as follows: Volatile organic compounds (VOCs); Semi volatile organic compounds (SVOCc); Fuels; Inorganics (metals, radioactive elements); and Explosives. A wide variety of treatment technologies is available.


Mining and agriculture rank together as the primary or basic industries of human civilization.  Mining encompasses the extraction of all natural occurring mineral substances – solid, liquid and gas – from the earth for utilitarian purposes. Open pit and underground mining plus tailings disposal ponds require geotechnical, geomechanics and geoenvironmental input through their life cycle stages.


In civil engineering, mining and earthworks projects success depends on vigilant and continuous onsite engineering inspection and testing to confirm that the materials and workmanship are in accordance with the relevant codes and guidelines, design specifications and construction drawings.


Earthquakes are caused by vibrations which occur when tectonic plates move against one another. The Richter Scale is used to measure the energy of an earthquake.

Volcanoes often form along oceanic ridges. The nature of a volcanic eruption depends on factors such as the composition and temperature of the lava within the earth.