Slide 1

P R O V I D I N G E N G I N E E R E D S O L U T I O N S June 2, 2014

1

ACTION INTERNATIONAL SERVICESCORE SERVICES

Groundwater Control (Dewatering) & Hydrogeological Investigation

Industrial Services & Equipment Rentals

Saudi ArabiaUnited Arab EmirateQatarOmanBahrain

DEWATERING CHALLENGES IN QATARHigh variation of Qatar geology & Hydraulics

Long procedure for permit

Lack of discharge facilities

Groundwater treatment & management

OVERVIEW OF QATAR GEOLOGY

QATAR GEOLOGY - AMC

Level (m, QNHD)

Reference: AMC-QDVC

HIGH VARIATION IN GEOLOGY/HYDRAULIC AMC AS CASE STUDY

150mSectionSection ASection BExcavation level (m QNHD)-20.675-11.485Horizontal Hydraulic conductivity (m/s)1.03E-44.61E-5Flow (m3/h) 10335

Section ASection B

PRESENT & PROSPECTIVE GROUND INVESTIGATIONCentered around Foundation with little or no dewatering consideration

Present Ground Investigation

Prospective Ground InvestigationDetailed Hydraulic test (vertical & horizontal Hydraulic conductivity)Groundwater physical & chemical analysisGeophysical test

APPROACH TO DEWATERING CHALLENGESDetailed Subsurface & Hydraulic AssessmentHistorical Information & Site ExperienceReview of soil investigation reportAnalytical modelling based on 1 & 2Numerical modelling (2D/3D) based on 1 & 2Insitu Test (Pumping Test & Slug Test)Recalibration of 3 & 4 based on 5.

APPROACH TO DEWATERING CHALLENGESStep 1:Visual Investigation/ Site visitHistorical Data/Dewatering Experience within locationSoil InvestigationReport

Numerical (2D/3D) & Analytical Model Step 2:

Pumping TestSlug Test

Insitu TestModel recalibration

3D MODEL FOR A METRO STATION IN QATAR

ADVANTAGES OF HYDRAULIC TEST PUMPING TEST

Estimate hydraulic parameters (vertical & horizontal hydraulic conductivity) which are important in designing cost effective dewatering system

It gives a wide range of aquifer properties on like Slug test and Percolation test which are location specific.

It gives good estimate of expected flow, pump requirement for dewatering works

It gives a better understanding of hydraulic behavior over a period of time

Analyses is more detailed with little uncertainty compared to other hydraulic test

GROUNDWATER MANAGEMENT PRACTICES

Sources of Water in QatarDesalination 48%

Fresh water from Aquifer 38%

Sewage water 14%Qatar is the second most water stressed in the world Water stress index 2011

Conservation PracticesOnsite treatment & Reuse

Onsite treatment & Discharge to sewer systemGroundwater recharge practices

Optimized groundwater design for dewatering by performing relevant hydraulic testSewer size due to discharge volumePermitExpected Treatment limit prior to discharge

GROUNDWATER DISCHARGE MANAGEMENTOnsite treatment & Reuse

Onsite treatment & Discharge to sewer systemGroundwater recharge practices

Optimized groundwater design for dewatering by performing relevant hydraulic testSewer size due to discharge volumePermitExpected Treatment limit prior to discharge

WHERE WE CREATE VALUESProject engagement

Understanding work program

Interpreting soil investigation report & geotechnical information for dewatering design

Recommendation of relevant Insitu hydraulic test based on project

Dedicated team Project Engineers & Hydrogeologist

Shared understanding of critical part & RiskSoil contaminationWater quality & Required treatmentPotential cavities/sinkholesExcavation type Open or Shored Flow Estimate & Discharge options

Tender Stage

WHERE WE CREATE VALUES

Sub. Contractor TenderUnderstanding work program

Recalibration of design/models and assumptions during the tender stage

Optimizing system to accommodate budget

Project ExecutionAdherence to standard practise

Daily system monitoring (Automated & Manual) and performance reporting againstLateral pressure (open excavation/shored system)Uplift pressure3. Dedicated Project & Site Engineers

WHERE WE CREATE VALUES

Tender Stage

Sub. Contractor Award

Contract Award

Sub. Contract Tender

Project ExecutionTeam continuity

Better program understanding

Good project management

Benefits

Thank You

17