The members of the l A E G commission who participated in the preparation of the guide were: prof. Milan Matula (President), Czechoslovakia; Professor G. For illustration (Figure 1.7) the Yarrow Reservoir ditch of the Liverpool Waterworks at Rivington is chosen.
Engineering geological mapping since 1950
Potentially the most important post-war development in engineering geology was the establishment of the British National Committee of the 1948 International Conference on Earth Mechanics and the Engin Foundation. At the same time as the Geotechnical Society was established, a group of founding members began publishing the journal Géotechnique, to encourage the pursuit of engineering geology in addition to soil mechanics.
Introduction
On the other hand, the purpose controls the scale of the map, and the scale dictates what can be displayed and thus the information that must be gathered to construct the map. Such information should mainly be obtained through an engineering geological survey that is specifically directed to the needs of the user, needs that may be perceived by the mapmaker or requested by the potential user.
Purpose
Mapping cannot be done without a suitable base map; base maps may be available at an appropriate scale, may be produced from existing maps for expansion, or may be custom-made. What can be done depends largely on the time and financial constraints already mentioned.
Scale
Classification and description of rocks and soils
Ideally, an engineering geological map should show rock and soil units based on uniform physical properties in terms of a spectrum of properties specified within a class. Attributes must be combined if the soil is to be mapped in terms of a small number of quasi-homo.
Classification of mapping units for engineering geological mapping
Complete descriptions of rocks and soils are reserved for the legends of small-scale maps, while large-scale plans may show the same rock type subdivided into separate map units based on one or more characteristics, for example the degree of weathering or connection. , or both. The problems of deciding which features of soils and rocks to show on maps have been discussed by Varnes (1974).
Ί Lithostratigraphical mapping units
- Engineering geological map units
As a map unit, it can be discriminated, for example, on the basis of weathering rate, frequency and pattern of discontinuity, strength or consistency. Only very general engineering geological properties can be defined for units that are only used on small-scale maps, smaller than Figure 2.2d).
Relation between engineering geological and lithostrati
The scale of the mapping is greater than 1:5000 and usually much larger; at 1:100 very detailed plans can be made. As a result, it is not possible to define the physical and mechanical properties of the entire formation, but only to provide data on the individual lithological types that compose it and to indicate the gene.
Other aspects of mapping
- Hydrological conditions
- Geomorphological conditions
- Active geomorphological processes
- Geodynamic conditions
- Princip/es of engineering geological zoning
- Symbols for engineering geological maps
Other Map Aspects 17 Table 2.1 Proposed nomenclature for engineering geological map units and their lithostratigraphic equivalents. In addition to the usual cartographic symbols, the following may be indicated by distinctive symbols on engineering geological maps.
Types of map
Nevertheless, the concept of zoning is important and useful in both small- and large-scale engineering geological mapping and environmental geological mapping. A map of an engineering geological area for special purposes can be prepared taking into account a certain type of engineering activity, for example, roads, dams, tunnels.
Introduction
- Scale
- Type and number of maps
Data collection
- Introduction
- Methods of conventional geological mapping
- Three-dimensional representation
- Types of data to be collected for engineering geological maps
- Documentation maps
- IVIethods of data collection
Sufficient structural data should be entered on the map to allow interpretation of the overall structure. Lithology, along with the physical properties of the rocks and soils of the various mapped formations, is an individual.
Derivative maps and plans
Mapping techniques for site plans
Introduction
Northeast of the Henry Mountains, up to 50 feet of massive gypsum occurs at the base. As an example, the two members of the Morrison Formation described above, which in some places cannot be immediately distinguished.
Early developments in rock description and classification
The engineering behavior of a jointed rock mass is probably more influenced by the character and filling of the discontinuities than their mere presence. If all possible descriptive terms are quantified, or illustrated when necessary, the result will be a modern version of the technical description of rocks for engine.
Principles of classification and description of rocks and soils
Bases for classification of rocks and soils for engineering purposes
A lithological classification of rocks
Description of rocks for engineering purposes
Ί Descriptive roc/c name
- Lithiological name
- Description of rocl< material
- Description of rock mass
The degree of weathering of the rock material can be described in terms of the degree of discolouration, weathering and decomposition from the fresh state (Dearman. The size of the blocks bounded by discontinuities can be described by the expressions in Table 4.10.
Description of weathering profile in rock mass
- Introduction
- Weathering profile
- Scale of weathering grades for a rock mass
- Diagrammatic representation of a weathering profile in massive
The distribution of the different degrees of weathering of rock material in the rock mass may be related to the porosity of the rock material and the presence of all kinds of open discontinuities in the rock mass. The distribution of weathering degrees in a rock mass can be determined by mapping natural and artificial exposures.
Classification of soils for engineering purposes
The alternation of different rock types in different proportions in a rock mass is most easily addressed by ignoring lithological variations and applying the weathering quality criteria set out in Table 4.12. However, isolated natural rock exposures and excavations of limited extent are not necessarily representative of the entire rock mass.
34;^ = INES(
Fine 1 Medium 1 Coarse Fine 1 Medium Coarse Fine 1 Medium 1 Coarse
- Description of soils
- Descriptive soil name
- Description of soil material
- Description of soil mass
- Weathering profile
- Additional geological information for rock and soil description
- Made ground
- Engineered fill
- Non-engineered fill
- Geological formation
- Effects of non-engineered fill on adjacent in situ rocks and
- Introduction
- Format and content of engineering geological maps
- Format
- Content of engineering geological maps
- Layout and content of engineering geological plans
- Format
- Content
- Supplementation of existing geological maps for engineering
- Recommendations for supplementation of existing
- Other aspects of presentation
- Number of maps and plans
The name of the finer material, which may be gravel, sand or silt, or mixtures thereof, must be given (see Table 4.13), e.g. It is not entirely satisfactory that important information should be printed on the back of the card sheet.
EXPLANATION
Explanation or legend
The explanation or legend on an engineering geological map provides guidance on the symbols used in drawing the map. Ideally, a general engineering geological map or group of maps should be accompanied by a descriptive memoir.
Legend for engineering geological maps and plans
- Symbols for soils
- Symbols for hydrogeological properties of rocks and soils
- Symbols for structural features
- Symbols for general features
Aquifers, aquifers, aquifers and aquifers can be distinguished in rectangles in the explanatory legends of maps and plans by a simple convention (Figure 5.11). Abbreviations may be used with line symbols to indicate the type of linear structure.
D LWMT HWMT
Symbols for glacial features Only a limited number of glacial features are listed
Comprehensive lists of geomorphological symbols are published by the International Geographical Union (1968) and only a selection is presented here (Figure 5.17). Erosional and depositional forms produced by mass movements can be mapped on a large scale using selected symbols for general features (see Figure 5.16), such as contour lines, springs, seeps, marshes, ponds, and sym.
Site investigation symbols
Symbols for shafts, tunnels, boreholes and wells
Symbols for use on cross- sections for engineering
SOFT SOIL DRILLING, with disturbed samples Q SOFT SOIL DRILLING, with undisturbed samples O SOFT SOIL DRILLING, with disturbed and. When the soft soil α well is drilled, the rock drilling symbol should be shown below the soft soil symbol and the two symbols enclosed in the α circle.
Co/our scheme
ROCK BOREHOLE, with core samples ROCK BOREHOLE - INCLINED rotating open hole. . ^ Dash indicates the direction of slope and the number is the deviation from vertical in degrees. All site survey symbols should be displayed in red except for piezometer readings, which should be in purple.
Another example of a legend
If suitable data are available, for example from deep boreholes, deeper layers can be shown on engineering geological cross sections and in the map interpretation. The results of chemical analyzes of groundwater are shown by blue circles divided into four sectors.
Introduction
- Zebera's stripe method of 1947
- Other applications of the Zebera stripe method
Practical Uses of the Line Method 69 ranges and still leave the map visually appealing and. The tape can accommodate the three superimposed layers in the surficial sediments above the bedrock.
Practical applications of the stripe method
- Engineering geological plans of Prague at 1:5000
In the late 1940s, detailed maps of some cities were produced in which the top 2 m, sometimes more, of the surface layer was ignored. The water-saturated alluvial plains in the bottom of the river valley, occasionally flooded at high water, are not suitable for any foundation.
Landslide areas
- Development of medium-scale 1:25 000 engineering geological
- Engineering geological 1:25000 maps of the Zvolen Basin
- Use of the stripe method in the Federal Republic of Germany
- Engineering geological map of Frankenfelde
- Application of the stripe method for other purposes
- Engineering geological
Sample analysis of individual holes Figure 6.6 Part of the documentation card accompanying the technical geological map of Prague (Plate 2). Use of the stripe method in the Federal Republic of Germany 11 Conventionally, the map legend provides the key to.
- Engineering geological map of the Creil (Oise) region
- Variations of the stripe method developed in Belgium and France
- Map of suitability of soils for foundations
- Application of the stripe method in the UK
- Introduction
- Classification and identification of map units
- Methods of classification
- Use of matrices
- Effect of map scale on selection of mapping units
- COMECON 'Instructions'
- The zoning concept
- Introduction
- General zoning maps
- Summary map of Slovakia at 1:500 000
The limited factual information from the pits has been extended across the map area based on known geologic conditions. Used in this way and with care, the complexity of the map layout can be acknowledged (Plate 7).
7.5-2 Summary map of the Zvolen Basin, Czechos/ova/(ia, at
Medium-scale zoning maps
- Zoning map of the Zvolen Basin, Czechoslovakia, at 1:25000
Conditions in the subzones are represented by schematic cross-sections (Table 7.4) of the soils and rocks. The lithology of the pre-Quaternary basement is shown by gray patterns of different weights, as on the map of engineering geological conditions.
Zoning plans
Varnes considers the map to be an excellent example, in full color and widely available outside Central and Eastern Europe, largely derived from a more or less conventional geological map of the real area. With such planning, it is more certain that the resulting area map will be satisfactory for a given purpose.
Other types of zoning map
- Unitized maps
A comparison of the small-scale composite map and the physiographic map shows the interrelationship between the two maps. The relative proportions of the upper and lower loess are used to define two subunits, Il-a and Il-b, in the carbonate bedrock.
The profile-legend method
If a conventional geological map were produced at this stage, it would show only the youngest deposits, which are present in most of the Dunkirk deposit area. The schematic cross-section (Figure 7.15) shows seven possible combinations, the main types of profiles (Figure 7.16) represent the primary distribution of the lithotheque.
Introduction
Engineering geological map of the world
- Zona/ geo/ogica/ units
- Regional geological map
- Map of zonal geological units
- Map of engineering geo/ogical types on the Earth
114 General or synoptic technical geological maps. upward movement, leading to the formation of a plain or highland topography. Geomorphological features are noted in the map legend, and descriptions of technical geological conditions are covered in detail in an accompanying memoir.
Engineering geological map of the USA
This map is a component used to prepare the Engineering Geologic Map of the United States. General Engineering Geological Map of the Soils and Rocks of Great Britain 119 It was emphasized in conclusion that these maps.
Content of general engineering geological maps
General engineering geological map of the soils and rocks of the
- Rock and soil classification adopted for the UK engineering
- Engineering geo/ogica/ maps
- Map of relative geological complexity in the bedrock
- Distribution of lithological types in the bedrock
- Importance of glacial till
- Distribution of superficial deposits
- General distribution of coarse and fine engineering soils
- Additional maps of engineering geological conditions
Following Radbruch-Hall (1979), one version of the map (Figure 8.10) shows the distribution of four degrees of geological complexity based on these criteria:. There is a close relationship between the geological basin. plexity of the rock, as shown in Figure 8.10 and the distribution of engineering soils and rocks in Figure 8.11.
Glacial terrain map of Britain
- Terrain evaluation
- Quaternary lithologies
- Glacial soils and their classification
- Distribution of glacial terrain types
- Discussion
Finally, soil conditions and landforms derived from periglacial conditions may overlap to varying degrees in the three terrain types described above, but dominate the unglaciated area south of the glaciation limit. Note the increasing dissection of the woody cover south of the last glaciation limit (see Figure 8.13).
Legend
SWAMP - SILTS AND CLAY WITH A HIGH PERCENTAGE OF ORGANIC MATERIAL; COMPRESSIBLE; HIGH WATER CONTENT; WATER TABLE GENERALLY NEAR SURFACE;. THICK ALLUVIUM - STRATIFIED SAND, SILT AND CLAY WITH GRAVEL AND/OR CLAY LENSES; HIGH WATER TABLE; SUBJECT TO FLOODING.
Lilili
Carpieres souterraines
Garrieres á ciel ouvert
IDIII
Techo caliza yvategua pypuku Profondeur du toit de la calcaire Techo caliza yvategua pypuku. Ijyvyku'i yvate pypuku Ijyvyku'i yvate pypuku Ijyvyku'i yvate pypuku A6cojiK)THaa οτινιετκα κροΒ/ΐΜ n e c M a H M K.
- Introduction
- PUCE system for terrain analysis
- Definition of terrain classes
- Classification nomenclature
- Moderately dissected surface 2.7 Moderately dissected eroded surface
- Rough rocky steep slope 3.3 Gentle slope
- Gentle dissected slope (to 5°) 3.5 Dissected slope (to 10°)
- Isolated ridges, etc 1 Low ridge (to 5° slope)
- Linear ridge (other than strike ridge) 5.9 Sand ridge
- Irregular eroded sloping surfaces, usually with rock outcrop or shallow soil
- Eroded sloping surface
- Undulating eroded sloping surface 6.5 Undulating dissected eroded sloping surface
- Moderately dissected mountain 7.8 Heavily dissected mountain
- Not allocated (reserved for fold mountains) 9. Drainage systems
- Major stream channel 9.2 Minor stream channel
- Lake, lagoon, billabong (oxbow lake) 9.6 Reticulated stream channel system (flood-out)
- Swamp or marsh 9.9 Sink hole
- Oxford-MEXE system of terrain classification
An example of the numerical nomenclature used for site classification is given in Table 9.7, but for a full description reference should be made to Grant (1975a,b). Tabulated are descriptions of the constituent site units in the site pattern, in the prescribed format.
- Land system map
- Larger land units
- Land system descriptions
- Other studies of land classification Engineering terrain units Terrain evaluation systems, all very similar in their
- Ί Northern Ontario Engineering Geology Terrain Study, Canada
- Remote sensing for land surface evaluation
- Ί Aerial photography
- Satellite imagery
- Interpretation of Landsat images
- Small-scale engineering geological maps
- Ί Northeast Corridor, Washington DC to Boston, Massachusetts,
- Introduction
- Interpreting geological maps for engineering purposes
- Introduction
- Interpretation of the geological map of the Alpine Quadrangle,
- Interpretation of an area of horizontal sediments
- Areal and engineering geology urban maps
After the introduction to the soil system follows a detailed description of the soil facets. The area analyzed is in the Alpine Quadrangle on the northern side of the Bonneville Salt Flats in Utah, USA.
Riie Maniii
- Oakland East Quadrangle, California, USA
- Maps of surface and underground quarries in Paris
- Introduction
- Engineering geological zoning maps of the 19th and 20th
- Uncovered geological and geotechnical plans of Warsaw
- Uncovered maps of geological conditions
- Maps of Prague: 1960-1978
- Methodology for 1:25 000 maps
- Methodology for 1:5000 maps
- Hong Kona: terrain classification for geotechnical purposes in
- Introduction
- Terrain classification mapping at the 1:2500 District scale
- Terrain classification map
One outcome of the study was the engineering geological zoning plan with a very detailed legend (Figure 10.7). A map has been drawn up of the areas exposed to the hazards associated with gypsum solutions.