Detailed Design of the Midrand K109 Road
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DETAILED DESIGN OF THE MIDRAND K109 ROAD Site Geotechnical Investigations Report: Detailed Design of the Midrand K109 Road Located Between K27 and Dale Roads, Midrand Area, Gauteng Province Prepared by RoadLab (Pty) Limited For: Aphane Consulting On Behalf of: Gauteng Provincial Government: Department of Public Transport, Roads and Works (Effective Date: 12 December 2014) RoadLab (Pty) Limited DOCUMENT INFORMATION Author (s): Kelvin Chimanya Associate Consultant: Eng Geology BSc (Honours), SACNASP Nico Herbst Senior Principal / Director Date: 12 December 2014 Project Number: APHA01 Print Date: Friday, 12 September 2014 Copies: Aphane Consulting (2) RoadLab (Pty) Limited (1) Document Change Control Version Description (section(s) amended) Author(s) Date 1.0 Final report Kelvin Chimanya 08-12-2014 2.0 Peer review Nico Herbst 10-12-2014 Document Review and Sign Off: Primary Author Peer Review Kelvin Chimanya Nico Herbst Detailed Design of the Midrand K109 Road Project Site Geotechnical Investigations Report RoadLab (Pty) Limited DOCUMENT INFORMATION Table of Contents EXECUTIVE SUMMARY ...........................................................................................................................i 1 INTRODUCTION AND TERMS OF REFERENCE ........................................................................1 1.1 Project Background ...........................................................................................................1 1.2 Terms of Reference ...........................................................................................................1 1.3 Scope of Work ...................................................................................................................2 1.4 Principal Sources of Information .......................................................................................2 1.5 Legislative Requirements ..................................................................................................3 1.6 Participants ........................................................................................................................3 1.7 Limitations and Declarations .............................................................................................4 2 PROPERTY DESCRIPTION AND LOCATION .............................................................................5 2.1 Project Description ............................................................................................................5 2.2 Location and Access .........................................................................................................5 2.3 Physiography .....................................................................................................................6 2.4 Climate ..............................................................................................................................7 2.5 Vegetation and Fauna .......................................................................................................7 2.6 Topography and Drainage .................................................................................................7 2.7 Weathering Characteristics ...............................................................................................8 2.8 Soils ...................................................................................................................................9 2.9 Proposed Land Use ...........................................................................................................9 2.10 Local Infrastructure & Services ...................................................................................... 10 2.11 Trafficability .................................................................................................................... 10 3 GEOLOGICAL SETTING............................................................................................................ 11 3.1 Regional Tectonic Setting .............................................................................................. 11 3.2 Regional Stratigraphy ..................................................................................................... 12 3.3 Project Geology .............................................................................................................. 15 3.4 Structural Geology .......................................................................................................... 15 4 FIELD OPERATIONAL METHODOLOGY ................................................................................. 17 4.1 Desktop Review .............................................................................................................. 17 4.2 Testing Procedures and Equipment Used ..................................................................... 17 4.3 Dynamic Cone Penetration Testing ................................................................................ 21 4.4 Rock Exposures ............................................................................................................. 21 4.5 Field Parameter Characterisation ................................................................................... 21 4.5.1 Residual Soil ......................................................................................................... 21 4.5.2 Transported Soil .................................................................................................... 22 4.5.3 Pedogenic Material ................................................................................................ 22 4.6 Key Geotechnical Constraints ........................................................................................ 23 5 LABORATORY TESTING AND ANALAYSIS ............................................................................ 25 Detailed Design of the Midrand K109 Road Project Page: 2 Site Geotechnical Investigations Report RoadLab (Pty) Limited DOCUMENT INFORMATION 5.1 General Overview ........................................................................................................... 25 5.2 Test Pitting & Profiling Results ....................................................................................... 25 5.3 Analytical Test Results ................................................................................................... 27 5.4 Dynamic Cone Penetration Test Survey ........................................................................ 34 6 ENGINEERING AND GEOTECHNICAL APPRAISAL .............................................................. 35 6.1 General Overview ........................................................................................................... 35 6.2 Geological Characteristics .............................................................................................. 35 6.3 Geotechnical Appraisal .................................................................................................. 36 6.4 Project Geotechnical Characteristics ............................................................................. 37 6.4.1 Undifferentiated Transported Soil .......................................................................... 37 6.4.2 Hillwash ................................................................................................................. 37 6.4.3 Alluvium ................................................................................................................. 37 6.4.4 Pebble Marker ....................................................................................................... 37 6.4.5 Residual Soil ......................................................................................................... 38 6.4.6 Weathered Granite ................................................................................................ 38 6.4.7 Granite ................................................................................................................... 38 6.5 Probable Impact on Road Design & Construction .......................................................... 38 6.5.1 Collapsible Soils .................................................................................................... 38 6.5.2 Expansive Soils ..................................................................................................... 39 6.5.3 Soft Clays .............................................................................................................. 39 6.5.4 Dispersive Soils ..................................................................................................... 39 6.5.5 Pedogenic Materials .............................................................................................. 40 6.5.6 Slope Instability ..................................................................................................... 40 6.6 Hydrogeology ................................................................................................................. 40 6.7 Structural Foundations & Sidewall Stability .................................................................... 41 7 INTERPRETATIONS AND DESIGN RECOMMENDATIONS .................................................... 42 7.1 Site Preparation .............................................................................................................. 42 7.2 Earth Works .................................................................................................................... 42 7.3 Geotechnical Recommendations ..................................................................................