Geotechnical & Structural Geology

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@IQ_UK Geotechnical & Structural Geology Institute of Quarrying Phil James BSc (Hons) MSc FCMI MIoD Julian Smallshaw FIQ, FHEA, BSc About The Institute 1917 Quarrying.

1 @IQ_UK Geotechnical & Structural Geology Institute of Quarrying Phil James BSc (Hons) MSc FCMI MIoD Julian Smallshaw FIQ, FHEA, BSc About The Institute 1917 Global extractives industry to improve health and safety to increase productivity to improve standards Delivering excellence in education and training Professionally qualified members 1

2 The Institute of Quarrying Purpose To advance the science and practice of quarrying, for the benefit of all Vision IQ is the beating heart of a vibrant world-class minerals industry Values Professional integrity Lifelong learning Ethical, sustainable practice The Institute of Quarrying 2

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4 Julian Smallshaw FIQ, FHEA, BSc Began career as a Quarry Manager 20 Years member of IQ 10 Years Institute of Quarrying 5 Years Head of Education Outline: Structural Geology Overview Geotechnical Engineering Overview A lot to do in a short time! 4

5 Structural Geology Description spatial representation and analysis of structural features Study of the forces that deform rocks and origin and distribution of these forces Unconformity 5

6 Folding A bend or buckle in pre existing structure caused by deformation Anti-form limbs converge upwards forming an arch anticline Syn-form limbs close downwards syncline Folds are described in terms of their attitude of the axial surface Fold Desription Upright Axial surface is vertical Overturned Inclined axial surface one limb inverted Recumbent Horizontal axial surface 6

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8 Anticline and Syncline Igneous rocks 8

9 Igneous Features Extrusive Rocks 9

10 Metamorphic Rocks Sedimentary Rocks 10

11 Sedimentary Rocks Outcrops An area where rock occurs at surface May or may not be covered with alluvium 11

12 Weathered Granite Outcrop 12

Strike the direction taken by the structural surface such as a fault or bedding plane as it

13 Dip and Strike Dip angle in degrees between a horizontal plane and an inclined rock stratum Measurement is perpendicular to the strike and in the vertical plane. Strike the direction taken by the structural surface such as a fault or bedding plane as it intersects the horizontal it is the compass direction of the horizontal line in the inclined plane. Dip and Strike 13

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$Faults Rock fractures at which displacement has taken place The rocks on either side of the break have moved$

15 Faults Rock fractures at which displacement has taken place The rocks on either side of the break have moved relative to one another in opposite directions Movement may be any amount in any direction on the fault plane Normal Fault 15

16 Reverse Fault Strike Slip 16

17 Slickensides Geotechnical Excavations Key Issues : Planar Failures 17

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19 Excavations Key Issues : Wedge Failures 19

20 Excavations Key Issues : Wedge Failures 20

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22 Excavations Key Issues : Toppling Failures Excavations Key Issues : Toppling Failures 22

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24 Common stabilizing measures: netting 24

25 Common stabilizing measures: netting Common stabilizing measures: pre-splitting 25

26 Excavations Key Issues : Rockfall / Unravelling over-steepened faces 26

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28 Summing up on Solid Failures Solid Tips Key Issues : Circular / Sliding Failures Unconsolidated Materials 28

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Liquid Tips (Lagoons) Key Issues : Design and Management Good Foundations Adequate Retaining Structures Adequate Well Positioned Overflows Adequate

32 Liquid Tips (Lagoons) Key Issues : Design and Management Good Foundations Adequate Retaining Structures Adequate Well Positioned Overflows Adequate Freeboard Seepage? Gullying? Erosion? Or, is there a risk of a circular or a sliding or other? type of failure that could lead to lagoon collapse 32

33 Liquid Tips (Lagoons) Key Issues : Design and Management 33

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36 Pit Design 36

37 But there are Inspections and there are Inspections! 37

38 Working Methods: Face heights / trimming Working Methods : Face heights / trimming 38

39 Working Methods : Rock traps / exclusion 39

40 Working Methods : Working practices Working Methods : Stockpiles 40

41 Working Methods : Stockpiles Reach and Capture Distance? Working Near Water 41

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43 IQ Skills Wheel 43

44 Thank you. Any Questions? Group and company pages 44

Stress and Strain. Stress is a force per unit area. Strain is a change in size or shape in response to stress

Stress and Strain. Stress is a force per unit area. Strain is a change in size or shape in response to stress Geologic Structures Geologic structures are dynamically-produced patterns or arrangements of rock or sediment that result from, and give information about, forces within the Earth Produced as rocks change