"Risk analysis and management -large EPC projects" , I prepared a paper ans submitted for Technology conclave Summit -TC IV , L&T Has giving opportunity of his group of employees to explore their skills by creating plat form in the name of Technology conclave and celebrating it's every year .In 2015 summit ,as a employee i submitted this paper and was selected for final presentation

1. Risk Analysis and Managements- Large EPC Projects
Palla Narasimhudu
L&T HEAY CIVIL INFRA I/C, CMRL UG Project, Chennai-10, Contact No. +919677124913, pallanara@lntecc.com
The demand for scientific management in different types ofprojects is constantly increasing, especially for project
base organizations, Engineering, Procurement and Construction (EPC) projects have become one of the more
popular methods of project execution by both clients and contractors. Risk Management, one of the critical
concepts of project management is interesting to focus on because of its advantages and capabilities.
Utilization of Project Risk Management methodologies, especially in large EPC projects can lead to huge
advantages on all aspects of projects’ development. It can also be implemented as the main reference and basis for
bidding, tendering and execution (including cost, time, resource, and quality management).
By risk identification, assessment and control, probable gaps between estimated and real cost,time, and quality of
projects can be prevented ordecreased.This approach also provides facilities to predict the final cost and end dates
of projects with a greater level of confidence.
Introduction
For a complex mega infrastructure project like construction of underground metro rail construction, risk
assessment should be mandatory during the conceptual and feasibility phase of the project. For effective risk
assessment, proper investigation and identification of the sources of risks need to be carried out by the risk
management team. These risks can be assessed or measured in terms of likelihood, impact and consequences.
The most appropriate way of dealing with the project risk is treating it as a function of likelihood and impact [Risk
= f (likelihood, impact)]. Finally, as risk is a component which cannot be eliminated, suitable risk mitigation
measures are to be suggested which will enable to reduce the identified project risks.
The major activities of the underground metro construction consist offeasibility studies,design,traffic diversion,
utility diversion, survey works, diaphragm wall works, soil and rock excavation, construction of decking, steel
struts, waterproofing, permanent structure works, mechanical and electrical installations and backfilling and
restoration works. The responses from the experts have been obtained through a questionnaire survey and the
consistency of the responses has been ensured through Delphi technique.
Case Study
Details of the project of underground metro rail taken as case study for Project Risk Analysis and Management is
described as below:
 Scope of work: Design and construction of Underground Stations at Nehru Park, KMC and Pachaiappas
College and Associated Tunnels- UAA-04
 Client: Chennai Metro Rail Limited (CMRL)
 Contractor: L&T SUCG JV
 Consultant: EMBYE Consortium
 Type of contract: Engineering Procurement and Construction (EPC)
 Contract Period : Feb-2011 to Nov 2015
 Total project cost: Rs. 958 Crores
Figure 1. Elevation of UAA-04 Project

2. Identification and Classification of Risks Involved in Construction of Underground Metro Station
The risks identified at each phase of the project and its subsequent work packages and activities are classified as
follows:
 Feasibility Project Risk
 Pre execution Project Risk – Design Risks
 Pre execution Project Risk – Technology Risks
 Execution Project Risk – Risks in traffic diversion works
 Risks in utility and traffic diversion works
 Risks in survey works
 Risks in diaphragm walling works.
 Risks in soil and rock excavation works
 Risks in construction of decking and steel struts installation
 Risks in tunnel mining and cross passage Construction
 Risks in instrumentation and monitoring of existing structures along the tunnel alignment
 Risks in permanent structure works
 Risks in mechanical and electrical installation works
Similarly for Feasibility, Design, Development and Execution Phase,tables have been formulated for identification
of the risks involved in the respective work. Considering all the work packages, the major type of risks identified
for the underground metro project can be grouped and listed as follows:
 Delay in ApprovalofDetailed Project Report (DPR)  Environment Related Risks
 Land Acquisition risks  Geo-technical Risks
 Design Risks  Major / Minor Accidents during Execution
 Technology Selection Risks  Unforeseen Heavy Rains
 Approval and Permit Risks  Force Majeure Risks like Flood, Fire, Earthquake
etc. Joint Venture Risks  Labour Agitation and Strikes
 Financial and Investment Risks  Inflation Risk
 Political Risks  Currency/ Commodities fluctuation
Some of risks encountered and their analysis and mitigation and further planning for avoiding future occurrences
are adopted which is illustrated in case study as below:-
1) Risks involved in Charted and Uncharted Utility Diversion at Nehru Park Station:
As per tender only four major wet utilities were to be divert to start the work, but during trail pit we found four
more uncharted and essentialutilities and all were crossing across the centre of the station box area and diverting
it was a bigger challenge for both charted and uncharted, required approval on every occasion after identification
and that too within the given timeframe. There was no extra time allotted for the uncharted utilities in the project
detailed programme. That meant the utilities were to be diverted along with the main works parallel with no extra
time
The risks involved in the diversion are as follows:-
Execution Risks-D-wall program and progress depending on the diversion ,all utilities were passing through one
location and crossing across the station boxand after diversion, the utilities were to be hang and protect in course
of roof slab excavation.
Because of the nature of the job, few contractors are available for doing this job, site conditions are dynamic and
connected to progress of D-wall construction, availability of those contractors for that time was the risk, and if
they are not available our program might be stretch
Adopted risk elimination/mitigation methods:
With the help of CMWSSB, BSNL, TNEB authorities, prior information to affected public and planned in non-
peak hours.

3. Space constraint, forced to plan introspect
ourselves and comes with the solution of inter
displacement and interchange, accordingly D-
wall construction was adopted. We identified
and trained one team to take off the diversion
works internally reduce the contractor
dependency risk
Risk Likely Consequences Action
Trial Pits Damage of utilities
Harm to Workmen
Problems to Public
Used Utility Identification Instruments
Proper PPE
Involved Local Authorities
Uncharted Utilities
other than tender
drawings
Delay in overall
program
Re-programming
Revising the different activities involving utilities
Space Constraint Affect main activities
Difficulty in managing
the diversion planning
Inter displacement/ Inter change of utility lines
Re-planning the sequence of D-Wall activities
Approval and Permit Activity may delay Submission of drawings and proposalfor both charted and
uncharted utilities just after identification and following up
on regular basis with clients for its prompt approval
Shortage of
Specialized agencies
Delayed start of work Developed utility team so that we need not approach
external contractors’ every time when there is a need
Availability of
materials
Increased Cost
Sudden Requirements
Greater Expense
Pre-planning of exquisite materials well in advance
Change in Alignment
due to erroneous
layout
Delay in execution
Rework
Checking the layout in beginning before start of work
Imparting training for a better understanding of drawings
and layouts
Utility Damage Affect other activities
Need to repair/ bring
new pipes
Additional Cost
For heavy/ bulk material handling, imparting training for
workmen and site personnel’s
A method statement/ SOP to be followed for the
procedures involved to avoid any damage
2) Risks involved in Traffic Diversion at Nehru Park Station
Approval and Permit Risks- Delay in Approval from the Clients/ Traffic police led to the start of the work a
month later than the actual planned. Had there the approval been granted on time, the site works and traffic
diversion works be started on time.
Land Acquisition Risks- The permission for land acquisition was granted in the very beginning of the project
during DPR submission but at later stage the traffic diversion plan changed due to site constraints like Change in
D-Wall Construction sequence and hence for speeding up the site overall progress,the two stages traffic diversion
was merged into one which carried away the risk of completing the other works in time. The proposal of land
acquisition for the revised plan was submitted and the delay in taking over the land by the local authorities delayed
the construction of road and thereby traffic diversion. The time which was saved in merging the two stages into
one got recompensed with the delay made in land handing over by the clients.
3) Design Change for Diaphragm Walls at Pachaiappas College Station
There was a change in the alignment of the entire station due to the agitation fromthe Pachaiappas College, where
most of the station parts lies inside the college land with green vegetation and so many well grown trees. Later,
Client- CMRL decided to shift the alignment adjacent to the college land carrying no environmental distraction
The entire decision making on the revised alignment of land took six months and eventually, the station
construction started after sixmonths
At beginning stage we designed and planned the programme with two TBMs, where sufficient buffer was there to
complete 7.0 km tunnel work. Tunnelling work started from Nehru Park to Egmore, but due to unforeseeable
Figure 2. Layout for Utility Diversion- Nehru Park

4. circumstances encountered due to hard soil strata led to double the time than planned. To catch up with the delay
made due to hard strata, clients asked us to bring an additional TBM.
Before starting construction activities, Land acquisition, provide service roads and Traffic diversion, utility
identification and diversion are related to stakeholder wishes and needs also dragged us a little bit.
All these concerns made us to re-evaluate the progress for speeding up the activities
Risk Likely Consequences Action
Change in Alignment of entire
Station
Delayed start of activities
Increased Scope of work
Revised layout submission
Elimination of struts at Base level by
modified design for D-Walls
Design change of D-Walls Change in Construction
sequences
Additional Cost
Additional time and Resources
Revision in the Excavation sequences
Excavation without Strut- region in
side station box carried out with
special care by excavating to a
maximum stretch of 12 m
Excavation without Strut Overall change in program
Failure to achieve milestones
Resource idleness
Additional Cost
Provision of a new opening at Roof
Slab to expedite the progress by proper
planning of resources
4) Collapse of Diaphragm Wall Panel No 147 at KMC Station
In underground structures deep foundation,there is chance of soil collapse, it is known and it can be controlled by
maintain the properties of bentonite/ poly-mud ,but unfortunately we maintained all properties in control but
external factors made unforeseen collapse of soil while grabbing of panel 147
The collapse of D-Wall Panel No 147 was happened due to the following reasons:-
 Grabbing in the soil was completed up to 24.8 m and since rock layer was encountered below 24.8m,
chiselling started to get the required level of 25.5m.
 Poly-mud level was 1.5mt below the Ground Level
 Due to the heavy rain there was contamination of seepage water
and polymer properties may reduce which may be insufficient
to withstand the top loose strata
 Due to continuous rain ,rise in ground water level immediately
below the guide wall due to the heavy rain, higher than the
poly-mud level
 Vibration due to chiselling
 Soil profile as per bore log data shown was silty sand up to
a depth of 8.5m but same strata continued from16m to 22m
 Quick sand formed surrounding panel area
Action taken due to the unforeseen risk:-
 Soon after the collapse, the incident was reported to clients
 Lean concrete was filled up inside the trench
The likelihood of occurring collapse of panel is 0.25 and a potential impact of 1 week delay in work and cost
increased by Rs 14 Lacs
Risk cost= 14 Lacs x 0.25= 3.5 Lacs
Risk Time= 1 week x 0.25= 0.25 Week
Remedial measures taken to avoid the risk in further panels grabbing:-
 By making bund over the guide wall, kept the poly-mud level always higher than the ground water level,
and also it was encountered with rain water inflow.
 Equal quantity of crusher dust was stoked for immediate risk mitigation.
5) Unforeseen Risks due to formation of Cavity in Diaphragm Wall panels at Pachaiappas
College Station
Bund
Figure 3. Bund for D-Wall P147

5. The cavity formed in the D-Wall panels, reason being, bad quality of concrete,honey comb formation, undercut,
over cut, soil collapse while concreting, improper fixing of Water bars at joints.
The panels observed with cavity were P101, P102, P112, and P113
Problems occurred due to the unforeseen risk were the following:-
 Sink hole development at the surface of the road due to the volume losses on running traffic adjacent to
the station box.
 Ingress of water inside the station boxcaused the excavation works to stop.
Action taken due to the unforeseen risk:-
 After reporting the issue to the traffic authorities, the
traffic was diverted.
 Backfilling was done nearby affected areas to avoid the
ingress of water from the cavity into the station area
 Mass concreting was done wherever the sink hole
occurred
 Steel plates were placed over the sink hole as an
immediate action to restore the traffic within 24 hours of
occurrence of the sink hole
 Contiguous pile was adopted outside the D-Wall face at
the affected location
 Provision ofgrouting column around the Contiguous pile
 Restoration of traffic to its original condition
The likelihood for cavity occurrence n D-wall panel is 0.25 and a potential impact of delaying work by 4 weeks
and adding the cost to the project by Rs. 44 Lacs.
Risk Cost= 44 Lacs x 0.25 = 11 Lacs
Risk Time= 4 Weeks x 0.25 = 1 Week
Remedial measures taken to avoid the risk due to cavity formation:-
In an underground structure it’s totally unpredictable that on which panel the defects are likely to occur. The
defects are identified once the excavation inside the station boxis taken up.The processes involved forminimizing
the future risks are highlighted below:
 Installation of bore-well adjacent to the affected D-Walls
 Lowering the water table with the help of installed bore wells
 Excavating inside the station boxnear the affected panel up to a depth of 1m
 Steel plate fixing at the affected location
 Micro-concrete grout in the affected panels.
 Following this sequence of excavation, steel plate fixing and grouting until the desired level is reached
and cavity is fully rectified.
6) Procurement Risks Analysis and Management
Risk Likely Consequences Action
Understatement of the
need
Purchase of unsuitable
product or service
Analysis of need accurately
Insufficient Funding Delay in making the
purchase
Obtain appropriate approvals before undertaking
the process
No response from known
quality of suppliers
Reduced competition
Increased cost of products
Need for improving our market knowledge
Figure 4. From left- Layout of D-Wall, Cavity for P101 and 102, Road Sink Hole
Figure 5. Contiguous pile at P101 and 102

6. Offers fail to meet needs Need to call tenderers again
Additional Cost
Delay in delivery
Conduct market research
Develop functionaland performance specifications
Selecting Inappropriate
Supplier and Product
Failure to fulfil the contract
and Client need resp.
Provide staff with appropriate tender evaluation,
financial and technical skills training and
commercial expertise
Risk due to Procurement of materials
During the procurement process, a recent case we came across, at the beginning of every year, the procurement
team asks requirement from every individual sites for the bulk materials like steel, cement, structural steel,
aggregates etc. Based on the available data from all sites, a final requirement is sent for approval to HQ for the
years’ work.
It was noticed in the go that the steel which was actually required for the years’ work was procured less than the
steel which was procured, reason being, and change in the program at the sites due to the change in the scope of
work by the clients. The cost for procuring the material was not properly utilised and again we had procure the
steel that was required. Thus an extra cost is incurred in purchasing the material for that period which we had
minimized by utilising the materials in later months by simply asking the requirements from the sites and using
the same inventory which we had procured at the very beginning of the year.
Risk Assessment Matrix- Examples cited above for UAA-04 Project
Probability
Very High
High 1, 6
Moderate
Low 3 2 4, 5
Very Low
Severity Very Low Low Moderate High Very High
Critical High Medium Low
Innovations in method of construction:-
 Inter displacement and interchange of Utility diversion Methodology to expedite Diaphragm wall
Construction for streamlining with the planned programme.
 Training of one team to take off the diversion works internally to reduce the contractor dependency risk
 Elimination of struts at Base level by modified design for D-Walls
 Provision of a new opening at Roof for carrying excavation without struts.
 By making bund over the guide wall, kept the poly-mud level always higher than the ground water level
 Installation of bore-well adjacent to the affected D-Walls and lowering water table to reduce the ingress
of water as a control measure to avoid the risk of sink hole.
Conclusion and Learnings:-
Based on the analysis done on severaltypes ofrisks,we concluded that risks can be managed to avoid its recurrence
in future, although, there are risks which are sizeable and takes lots of experience until it is managed.
 We get to know about the varieties of risks and their assessment for various site conditions.
 Assessment is mandatory for each and every site activity, no matter, what is its significance.
 Contingency plan to be followed for high risk activities.
 Close and continuous monitoring is required for its mitigation.
 Timely action and decision taking is also needed.
 Incorporation of previous projects experience help to mitigate the new risks.
 All risks happened at site and its mitigation plans definitely help for great extent in future risk
assessments.