Managed Motorway Ground Investigation Process Improvement
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Transcript Managed Motorway Ground Investigation Process Improvement
TCF Task 242 – Managed Motorway Ground
Investigation Process Improvement
Lean Project Improvement Presentation Slides
Objectives
Understand how Ground Investigations are currently
undertaken
Develop an improved process with realistic timescales
Ultimate deliverable would be a best practise guide
(beyond the scope of this commission)
Original Commission and Appraisal Work
Ground Investigation (GI) surveys on Tranche 1
Managed Motorway schemes were perceived to be
costly in terms of budget and programme. These
issues were perceived to be related to the
procurement and delivery mechanism utilising the
MAC.
Jacobs was originally commissioned to prepare a
business case for setting up a national ground
investigation framework
Ground Investigation Framework Study Findings
Jacobs collected and collated data following request
for information covering:
Procurement route
Scope of work
Programme
Costs
Traffic Management
Other comments
Data was received from 4 managed motorway
schemes, 3 other motorway schemes, 2 highway
schemes and 2 existing frameworks
Ground Investigation Framework Study Findings
Single occurrence GI costs
£900,000
£800,000
£700,000
£600,000
Other
£500,000
Traffic Management
GI Works
£400,000
Supervision
£300,000
£200,000
£100,000
£0
M1 J10 to M4 / M5
13 MM
M40
M62 J18 M60 J15 M60 J8 to
to 20 MM to 12
12 MM
Since GI is conventionally
undertaken as a phased
process, in some instances,
this is just the cost so far
Time
M4 / M5 anticipated 67 shifts,
actual 75 shifts
MMM anticipated 10 weeks,
actual 20 weeks
Not all schemes provided
data!!!!
Ground Investigation Framework Study Findings
Procurement routes:
Many routes are currently implemented
No single option presented itself as an ideal solution
Framework:
Advantages include one-off procurement and greater consistency /
visibility of rates
Disadvantages include:
Initial set-up time / costs, may not overcome traffic management issues
Lack of integration with the MAC and other network operations
Cost and programme could still be key issues if not procurement related.
MAC
Advantages include knowledge of the site, TM, quicker mobilisation
(operational planning expertise, integration with other network
occupancy, etc)
Disadvantages include perceived excessive costs, programme overruns
lack of ownership and under resourcing management of the GI
Ground Investigation Framework Study Findings
Cost and programme comparison:
Little evidence that rates are inconsistent or unreasonable
across procurement routes
Procurement route has little effect on programme
Traffic Management:
Greater control and flexibility of TM if GI procured through MAC
Undertaking TM flexibly, managed by short-term programming
and effective communication improves efficiency
In some instances, TM costs were approaching half the cost of
the investigation
Technical scope for the GI can significantly affect cost &
programme if change is required during the works.
Ground Investigation Framework Study Findings
Outcome:
Large quantity of factual and anecdotal evidence collected
Procurement is not necessarily the issue – jumped to a solution
without fully understanding the problem
Findings relate to issues around:
Traffic Management
Planning
Process
Appropriate technical scoping and specification
Measure
What generally happens:
GI data is used to manage the geotechnical risks associated with the construction of infrastructure and is used to inform the design. The ultimate
objective is to produce a safe design that is technically and commercially efficient.
Traditionally GI is a phased process aimed at reducing uncertainty and risk as a scheme develops. Initial GI undertaken based on “initial design” and
used to gain a general understanding of the ground conditions, design develops, detailed GI required, design possibly changes further, supplementary
GI required, etc, etc
Design Development (during Stage 2)
Prepare Desk
Study & Scope
Initial GI
Detailed Design (during Stage 5)
Is known to have
occurred more than
once in Stage 2
Is known to have
occurred more than
once in Stage 5
Scope Detailed GI
M62 J25-30
£400,000
Procure GI
M62 J25-30
£95,000
Procure GI
Undertake GI
Undertake GI
Testing &
Reporting
Testing &
Reporting
PRE-CONSTRUCTION
Construction (design may change further)
M62 J25-30
£200,000
Scope
Supplementary GI
Procure GI
Undertake GI
Testing &
Reporting
CONSTRUCTION
Measure
Manchester Managed Motorway Value Stream
Mapping exercise
Key issues encountered:
Adverse Weather
Discovery of Services
CDM Co-ordination
Scope Quality
MAC Pricing
Landowner Objections
Great Crested Newts
Measure
Summary of Manchester Managed Motorway GI
What went well:
No accidents / incidents
Weekly GI progress meetings
Consultants came together
for a common approach
Management of network
occupancy
AOne+ and Costain flexibility
What could’ve gone better:
Too many designers / CDMCs
Technical specification more
appropriate to the operating
environment
Insufficient on-site management
Project Sponsor unfamiliar with
the process
Greater time and effort required
in the preparation for the works
(planning of shifts, access and
network occupancy)
Lack of permanent site ecologist
Time of year – weather,
embargos
Measure
Value Adding / Non-Value Adding process map
Measure
NVA elements identified:
CDM Role Consideration
Specification submission to MAC
Mobilisation
TA process to approve the use of Sonic Borehole Technology
Discovery of Services
Pegging Out Services
Great Crested Newts
Landowner Objections
Measure
Failure Modes and Effects Analysis Workshop held on
14 February, key failure modes and causes:
Failure to do boreholes in planned locations due to services in
the verge found during GI (see next slide)
Delay appointing single CDM-C role – too many CDM-Cs /
Designers, lack of appreciation
Reworking of GI scopes due to design changes and additions
GI design – change in GI technique to reflect operating
environment during the works
Measure
Services located in the verge
are “pegged” out by the
TechMAC using similar
images / information
On site the GI Contractor has
no indication where exactly
the services (cables) are or
how many
The number of services in
the verge and the inability to
work around them forced the
GI Contractor to move to the
hardshoulder during the night
Improve
Improvement Workshop held on 22 March 2011 to:
Validate the current situation
Validate occurrences on Manchester Managed Motorway
Test macro improvement options
Test process improvement options
Why do we need to do GI on Managed Motorway
schemes?
To manage the risks to obtain a safe and economic design
To obtain a level of confidence in ground condition
GI very rarely affects the gantry locations
Improve
Current situation validated:
M62 Junction 25 to 30 about to undertake third GI – attributed to
design changes
Birmingham Box Phase 3 about to undertake second GI – design
changes and need to determine foundation (pile) solution
Manchester Managed Motorway GI validated against
occurrences on Birmingham Box:
Programme pressures lead to limited planning time
Competition on network for road space booking (TM)
The GI design / work scope didn’t properly understand and reflect the
constraints of the operational environment
Improve
Macro Improvement Options – no pre-construction GI
Contractor undertakes GI during Construction Phase. The
key differences between current situation are:
No GI pre-construction
Would require more designer input during construction
Potential saving on TM duplication, i.e. during options then
construction
Significant reduction in the chance of service strikes and the
ongoing need to re-position exploratory holes
Potential lack of appreciation of major geology features / issues
Dependence on site environment
Could increase risk allocation leading to issues with target cost
Improve
Macro Improvement Options – no pre-construction GI
What would we do?
Set out and agree approach to GI and geotechnical certification (Statement of
Intent).
Desk Study – Preliminary Sources Study Report
Isolated GI to target key risk areas, i.e. 1 or 2 boreholes during pre-construction
to augment PSSR. Challenge the need for GI at this stage and require rigorous
justification.
Prepare matrix of foundation solutions for Deliver Partner to undertake Target
Cost including risk allocation
During construction:
TM established on site
Verges cleared (services, barriers, etc)
Undertake GI at exact locations
Testing and interpretation
Select foundation solution
Structural and geotechnical certification
Construction
Feedback report to capture GI data
Improve
Macro Improvement Options – no pre-construction GI
For / Benefits:
The perfect “pull” project
Design fixed and GI undertaken with
certainty
Significant pre-construction cost saving
GI only undertaken once – cost savings
Efficiency – TM, verge clearance, site
welfare
Stakeholder interface more controlled
Standard solutions deliver potential
efficiency
Potentially forces Designer / Delivery
Partner to value manage the GI
Against / Disbenefits:
Potential to impact duration of
construction period
Increased pre-construction risk
The AIP (structures certification) process
GI in construction could be blocking the
site
Conservative foundation solutions
Greater designer input during
construction (good or bad – undecided!!)
Implications on perceived rigid structure
of PCF
Macro Improvement Options
Macro Improvement Options – Single pre-construction
GI
Designer / Delivery Partner has one opportunity to undertake
GI. The key differences between current situation are:
The need for GI is challenged
Undertake GI once
Undertake GI as late as possible during Stage 5 detailed design
Greater chance of design fixity during detailed design
Improve
Macro Improvement Options – Single pre-construction GI
What would we do?
Agree approach – prepare Statement of Intent
Prepare Preliminary Sources Study Report
Prepare strategy, scope and specification and challenge the need for GI
Procurement
Move into Phase 5 – Delivery Partner appointed
Undertake GI
The GI would then be used during Detailed Design and Target Cost
preparation with the objective is to reduce / manage risk allocation
Improve
Macro Improvement Options – Single pre-construction GI
For / Benefits:
Cost saving by undertaking once
GI results / findings can inform
the detailed design
Should reduces risk (time / cost)
during preparation of Target
Cost
Follows the current PCF process
Fewer site visits, potentially
reduces impact on stakeholders
Potentially forces Designer /
Delivery Partner to value
manage the GI
Against / Disbenefits:
The GI is still undertaken before
target cost design freeze, i.e. the
design may change
Potential inflexibility of
undertaking single GI
Potential to over scope GI if it’s
only undertaken once
Still has many of the potential
disadvantages of the current
approach in terms of potential
costs / delays / TM / conflicts in
network occupancy
Improve
Further points to consider from the workshop:
GI is only undertaken during construction stage of Network
Rail’s electrification schemes
Design the GI (techniques and scope of work) with the
operating environment in mind
Don’t assume GI needs to be undertake immediately
Two hit GI is the traditional way for green-field schemes
We are not Value Managing GIs
Agreed by Designers and TAA at the workshop that no GI in
pre-construction phase should be the starting point
Improve
Lessons learned:
Agree roles and responsibilities at the start
Understand the constraints, embargos, working times, etc
Write the specification for the GI with due regard for the site constraints
Recognise all constraints include services, working space, barrier, fencing, lane
restrictions, etc
Get to know and liaise with the MAC and Network Operations Managers
Resource the site works adequately (day to day project management)
Engage with the Environmental Coordinator early
Agree GI Scope / Specification with TAA around a table
Agree format of the pricing schedule early (inc. level of detail)
Undertake GI as late as possible in the programme
Improve
High-level process:
Undertake GI during construction should be the default route
Project Sponsors, Project Managers and TAA would need to be
convinced to undertake GI earlier
PCF Stage 2 – Options
Scheme Concept and Outline
Design
PCF Stage 5 – Pre-Construction
Environmental and
Economic Assessments
Preliminary Design
Detailed Design
PCF Stage 6 – Construction
Target Cost
Construction
This is the default route
Key decision
Data Gathering
Preliminary
Sources Study
Report
Yes
Undertake
isolated GI for
key risks if req
No
Prepare strategy,
scope &
specification
Prepare
strategy, scope
& specification
Undertake GI
during
construction
This is the non-preferred route
Undertake
single stage
GI
Testing &
Reporting
Undertake
GI
Testing &
Reporting