East Land Quality Forum Drilling Techniques; Old and New 1
Introduction Different Drilling Methods Rota-sonic drilling What is it and how does it work? Different types of Rota-Sonic/Sonic Drilling Rigs Benefits of using Rota-sonic Drilling Rota-Sonic Project Examples Cost Comparison Summary 2
Different Drilling Methods 3
Different Drilling Methods Range from the good, the bad and the ugly Dynamic Sampling Hand Held Tracked Rig Cable Percussive Rotary Drilling Geo-borS Reverse Circulation Down hole hammer Sonic Rota-sonic Resonance Drilling Other Methods of forming a borehole Direct Push (DPT) - AKA Geoprobe CPT 4
Direct Push Basic Capabilities Soil Sampling Single / Dual tube Soil Vapour and groundwater Sampling Coring concrete Traditional Rotary (mud / air) Utilise augers Grouting and Injection New (ish) developments Utilise CPT Membran Interface Probe (MIP) Electrical Conductivity Limitations Relatively small samples (72mm dia.) Limited casing capabilities Limited to softer ground conditions 5
Rota-Sonic Drilling What is it and How does it Work 6
Basic Principle of Rota-Sonic Drilling Vibratory Force Energy @ face of bit achieves localised displacement to shear and penetrate Rotary Force Slow Rotation to enhance energy & penetration of hard layers Axial Force or Feed Force Steady down pressure to aid advancement 7
Basic Principle of Rota-Sonic Drilling 8
Different Types of Rota Sonic/Sonic Drill rigs 9
Different Types of Rigs 10
Rota-Sonic or Sonic Drilling Method Rota-Sonic Drilling Rotation, Sonic and axial/feed force Sonic Drilling Sonic and linear/vertical down feed Depth Capability 200 to 250m depending on ground conditions Approximately 30m depending on ground conditions Ground conditions Max BH Diameter Max Sample size Max Install Size Anything! can drill through obstructions which other methods refuse 300mm (12 inches) 254mm (10 inches) 185mm OD Loose sands and gravels, soft clays, very weathered rock, will hit refusal on boulders and man made obstructions 125mm (5 inches) 102mm (4 inches) 33mm OD or 42mm OD pre-pack screen 11
Benefits and Advantages 12
Differentiators Safety Site Conditions Red Site Suitability High Quality Sample Continuous Core Higher Quality Undisturbed Sample Not Subject to Refusal Can Rotary Core Bedrock 13
Benefits and Advantages - Safety Limited lifting required Lighter tooling Automatic rod breaking Rig guarded Remote Operating Panel Serious finger and hand injuries are common Poor guarding Manual Handling and Heavy lifting can t be avoided Rig stability during installation Inherently un-safe operation Not a career option 14
Benefits and Advantages Site Conditions Clean Site Control of Arisings Control of Contaminated Materials Easy to Remediate site Accessible to more difficult locations Very difficult to keep site clean Additional hazards operating in muddy conditions Not suitable in Red Site conditions Can leave deep ruts from drive access 15
Rota-Sonic Undisturbed Sampling Rota-Sonic Borings are cleaned and cased to bottom before UD sampling begins. Can use any UD sampler requested U100, UT100, Window Sampler, Shelby Tube, Thin Wall Sampler Double liner barrel system can be used within Stiff Clays e.g. London Clay Engineer can make an informed decision on where to take UD sample from visual analysis of previous core sample Sampling is very controlled using rigid rods and direct push repeatable process 16
What is the True Cost of Refusal? How Much Chiselling is acceptable? Boreholes not going to target depths Mis-interpretation of Bedrock Depth Loss of critical interchange strata information Difficult to interpret a handful of chips 17
What is the True Cost of Refusal? How Much Chiselling is acceptable? Typical Example Kishorn Dam Site Investigation Geotechnical Investigation of Dam in Scottish Highlands SSSI Site Very Difficult Drilling Conditions Large boulders Cobbles Gravel Other contractors declined to tender. Typical Example Glasgow Site Investigation Previous Investigation with cable tool determined bedrock at 14m. Piles for a bridge foundation were designed and installed to 14m. After failure of test pile Sonic Proved Bedrock between 23m and 27m depending on location. 18 Rota Sonic is not subject to Refusal
Rota-Sonic Samples 19
Rota-Sonic Sample Undisturbed? Rota-Sonic Sample Quality Class - BS EN 1997-2:2007 Material Dependant Sands and Gravels Quality Class 3 (5) Soft Clay, alluvium Quality Class 3, Class 2 also achievable (4) Stiff Clays Quality Class 2 is achievable (4) Sample class B and A is also achievable (density, density index, Permeability, porosity) Utilise number of different drilling tools. (5) = Quality Class/ Sampling Category in EN ISO 22475-1 20
Granular Material Sampling Sample often dumped on ground mixed with other materials Identification of changes in strata is difficult Contamination sampling is indicative only Shell Sampling - action of sampling hydraulically surges the boring Loss of fines is common Sample is non-representative and requires a lot of interpretation 21
Rota-Sonic Benefit High Quality Samples Continuous Core Sample Controlled extrusion of sample Safe handling for contaminated samples No dilution/crosscontamination of sample Engineers get to log the facts Not interpret the losses Make decisions on borehole based on visual evidence 22
Rota-Sonic Benefit High Quality Samples Clear Definition of strata change Continuous Core Sample Highly representative Recovery in Made Ground Clear identification of contaminated strata Very precise sub-sampling No Loss of fines Recovery in Granular Materials 23
Rota-Sonic Benefit Sample Variety Easily Altered Geology Stiff Clay 24
Rota-Sonic Benefit Sample Variety Core with Sonic Barrel Core with Diamond Barrel 25
Rota-Sonic Benefit Drills Through Difficult Materials Reinforced Concrete Large boulders & Cobbles cored Cable Tool would have presumed bedrock No Loss of Critical Interface- Weathered Rock 26
Rota-Sonic Benefit Sample Variety Steel train rail Fused Slag NOT SUBJECT TO REFUSAL - Even in hard strata and difficult made ground 27
Rota-Sonic Benefits Iso-Flow System 28
Rota-Sonic Benefits Quality Installations Installations are assisted by the vibration from the Rota-Sonic system; Reduces the risk of bridging occurring and standpipe moving during extraction of drill casing; Positive displacement of filter sand increases the quality of the pack; Positive settlement of bentonite granules/pellets increasing the quality of the seal. Limited smearing in clay formations; Able to drill dry in most formations reduces the amount of water required for extraction during the development of groundwater monitoring wells. If water is added to aid drilling it is minimal and at low pressures, reducing the risk of hydrofracturing and removal of non-cohesive materials. 29
Rota-Sonic Project Examples 30
Rota-Sonic Project Examples Old Gas Works Ireland 140 No. boreholes drilled using Rota-Sonic; RED Site Drilling Conditions Environmental investigation Mixture of 4m and 10m deep boreholes Advance through concrete, granular materials and bedrock. Drilling between 50 to 60m p/day 31
Rota-Sonic Project Examples Chemical Works South Wales 125 No. boreholes drilled using Rota-Sonic; RED Site Drilling Conditions Environmental investigation Mixture of 6m and 15m deep boreholes Advance through concrete, made ground, drift deposits and bedrock. 32
Rota-Sonic Project Examples M74 Extension Glasgow Over 7000m drilled using Rota-Sonic for; Geotechnical sampling and In-situ Testing SPT s, U100 s Mineshaft Investigation Installation of Geotechnical Instrumentation Inclinometers Installation of Remediation Systems RED Site Drilling 33
Rota-Sonic Project Examples Olympic Site London Over 75No. boreholes drilled using Rota-Sonic for; Geotechnical Sampling and in-situ testing Environmental Sampling RED Site Drilling Drilled to depths exceeding 50m Advance through Made ground, London Clay Gravel, Lambeth Group, Thanet Sands, Chalk and Flint Bands. 34
Rota-Sonic Project Examples Petrol Station Filling Forecourts Reduced Height Mast available Can Drill completely dry if required Reduces risk of sample bias Reduces risk of removal non-cohesive materials Reduces amount of waste drill flush 35
Rota-Sonic Project Examples Specialist Sites Nuclear Licensed Sites Drigg, Sellafield, Sizewell, Hinckley Drilled in excess of 500 boreholes on Nuclear related GI s. Gas processing plants Refinery Sites Rigs, containment system, method of working working modified to work on specialist sites. 36
Cost Comparison 200m Geotechnical SI 37
Cost Comparison 200m Geotech SI Drilling Difficulty Definitions Easy Soft, Sandy Clays Medium Medium Density Clays, sands & gravel, occasional cobbles Difficult Glacial Till, Dense Gravel bands, large cobbles, made ground Very Difficult Large Boulders, Blowing Sands, Dense Gravel Bands, Dense Sands, Made Ground with obstructions, re-inforced concrete. Average CP Costs per day range - 550-800 Average Sonic Rig costs per day range - 2250-2850 Average Engineers cost per Day - 400 Average CP production rates range from 15m to 3m (this is assuming total refusal is not reached) Average Sonic Rig production rates range from 25m to 13m 38
Project Cost Cost Comparison 200m Geotech SI 200m Geotechnical SI Project 100,000.0 90,000.0 80,000.0 70,000.0 60,000.0 50,000.0 40,000.0 30,000.0 20,000.0 10,000.0 0.0 Easy Medium Difficult V.Difficult Drilling Difficulty CP Rig BL Sonic Sonic becomes cost effective for Medium difficulty projects 39
Is Rota-Sonic Cost Competitive? Cost Comparison 200m Geotechnical Project Cost of mobilising a Rotary Rig for Bedrock Definition Cost of waste disposal (Red-Site) Cost of Site Remediation Cost of Second Phase of Drilling Due to in-sufficient data Cost on being on-site longer welfare facilities, site possession etc A higher tender price for construction works A claim for un-foreseen conditions on construction projects A well that doesn t produce A more expensive remediation project A bigger reduction on land price valuation A penalty for late delivery of a project 40
To Conclude 41
Conclusions Raise the awareness of rota-sonic drilling / it s capabilities Another drilling method for your toolbox Very Versatile Drilling System Provides many advantages for completing both Brownfield / Contaminated Land and Geotechnical GI s 42
Conclusions Myths and Facts Can Rota-Sonic drill for VOC s? Can Rota-Sonic drill dry? Can Rota-Sonic Penetrate all materials? Can Rota-Sonic Provided a Representative Sample? Can Rota-Sonic Provide Undisturbed Samples? Can Rota-Sonic Provide SPT s? Is Rota-Sonic cost competitive? 43
Boart Longyear E&I Thank you for your Time Any Questions? Wesley Wray Boart Longyear E&I Business Development Manager Tel: 01259 727780 Email: wesley.wray@boartlongyear.com 44