https://elreedyman.com Thu, 28 May 2026 12:30:39 +0000 en-US hourly 1 https://wordpress.org/?v=7.0 https://elreedyman.com/wp-content/uploads/2025/01/cropped-81f184e734274fb2b6800b09ddd614cb-free-1-32x32.png https://elreedyman.com 32 32 Cost Estimation in Engineering Projects https://elreedyman.com/cost-estimation-in-engineering-projects/?utm_source=rss&utm_medium=rss&utm_campaign=cost-estimation-in-engineering-projects Thu, 28 May 2026 12:12:59 +0000 https://elreedyman.com/?p=83129 One of the most underestimated disciplines in engineering and project management is cost estimation. Many people believe it is simply […]

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One of the most underestimated disciplines in engineering and project management is cost estimation. Many people believe it is simply a matter of calculating quantities and applying unit prices. In reality, professional cost estimation requires extensive technical knowledge, market awareness, practical experience, and strategic thinking.

After more than 35 years of experience in offshore, industrial, and infrastructure projects, I can confidently say:

Accurate cost estimation is one of the main keys to project success.

A small error in estimating project costs can lead to:

  • Financial losses
  • Project delays
  • Contract disputes
  • Cash flow problems
  • Poor investment decisions
  • Failure to win competitive bids

Cost Depends on Perspective

The same project may have completely different cost views depending on who is evaluating it:

  • Owner
  • Contractor
  • Supplier
  • Consultant
  • Investor

Each party analyzes the project from a different financial and commercial perspective.

For example:

  • The owner focuses on budget control and lifecycle cost.
  • The contractor focuses on execution cost and profitability.
  • The supplier focuses on manufacturing and delivery margins.
  • The consultant focuses on technical compliance and project optimization.

Cost Estimation Is Never an Exact Number

One of the biggest misconceptions in engineering is believing that project cost is a fixed value.

In reality:

Every estimated number contains uncertainty.

The level of uncertainty depends on:

  • Project type
  • Project phase
  • Available engineering data
  • Country location
  • Economic conditions
  • Market volatility
  • Material availability
  • Contractor capability
  • Political and environmental risks

This is why contingency is added to project estimates.

In many projects, contingency may range between:

  • 10% for mature projects with detailed engineering
  • up to 40% or more for conceptual or high-risk projects

Selecting the correct contingency value requires engineering judgment and practical experience.

Parametric Cost Estimation

In many industries, engineers use parametric estimation methods to develop preliminary project costs.

For example:

  • Cost per square meter or square foot
  • Cost per ton of steel
  • Cost per kilometer of pipeline
  • Cost per MW of power generation
  • Cost per offshore platform weight

I am frequently asked:

“How much will it cost to build a new home?”

The answer depends on:

  • Building location
  • Construction quality
  • Material specifications
  • Number of floors
  • Soil conditions
  • Architectural requirements
  • Local labor market

However, experienced engineers can quickly develop preliminary estimates using historical project data and parametric models.

The quantities of steel reinforcement, concrete, and cement consumption can also be approximately estimated based on practical engineering ratios and previous projects.

These concepts are discussed in my engineering publications, including:

“Building Home Q&A”

Cost vs Price

For contractors, the final submitted value is not called “cost” — it becomes:

The Bid Price

The bid price includes:

  • Direct cost
  • Indirect cost
  • Risk allowance
  • Overhead
  • Profit margin

Submitting the best price is one of the biggest challenges in construction and EPC contracting.

A successful contractor must understand:

  • Market conditions
  • Competitor behavior
  • Client expectations
  • Procurement strategy
  • Financial evaluation methods
  • Technical scoring systems

In many tenders, the lowest bidder wins. Therefore, contractors try to optimize their proposals to reduce costs while still satisfying the minimum client requirements.

However, this creates a dangerous situation.

If a contractor submits an extremely low price without fully understanding:

  • the client quality expectations,
  • project complexity,
  • or hidden risks,

the project may enter a serious financial and execution crisis.

Cost Estimation Is Part of Daily Life

Interestingly, every person performs basic cost estimation every day.

When purchasing:

  • a car,
  • food,
  • electronics,
  • or a house,

people naturally estimate:

  • affordability,
  • value,
  • and expected future expenses.

But in large engineering projects, the complexity increases significantly due to:

  • technical uncertainty,
  • procurement challenges,
  • construction risks,
  • and market fluctuations.

Escalation and Inflation Factors

Another major challenge in cost estimation is adjusting historical project costs to current market conditions.

This requires understanding:

  • Cost escalation
  • Inflation
  • Currency fluctuation
  • Material price trends

What Is Cost Escalation?

Cost escalation is the increase in the cost of products, materials, labor, or services over time.

For example:

  • Steel prices
  • Cement prices
  • Fuel costs
  • Equipment manufacturing costs
  • Shipping rates

may change significantly between project phases.

A cost estimator must evaluate:

  • future market trends,
  • economic stability,
  • and country-specific risks.

These factors directly affect project profitability and investment decisions.

International Cost References

Many engineers use international cost databases and references such as:

  • ENR (Engineering News-Record)
  • RSMeans
  • International construction indices
  • Historical company databases

However, engineers must be careful when applying international norms because:

  • U.S. market conditions,
  • European labor costs,
  • and regional supply chains

may differ substantially from projects executed in the Middle East, Africa, Asia, or developing countries.

Learn More Through My Books and Engineering Courses

If you are interested in:

  • Project cost estimation
  • EPC project management
  • Construction economics
  • Offshore and industrial projects
  • Structural engineering
  • Engineering procurement and contracting
  • Risk and contingency analysis

You can explore my engineering books and online courses available through:

Publications:

https://elreedyman.com/publications/

Udemy Engineering Courses:

https://www.udemy.com/user/mohamed-a-el-reedy/

These resources are designed for:

  • Engineers
  • Project managers
  • Contractors
  • Cost estimators
  • Consultants
  • Construction professionals
  • Engineering students

Final Thought

Cost estimation is not simply mathematics.

It is a combination of:

  • engineering,
  • economics,
  • market intelligence,
  • practical experience,
  • and risk management.

The most successful estimators are those who can combine technical understanding with commercial awareness to make realistic and reliable decisions.

Dr. Mohamed A. El-Reedy
Structural and Offshore Engineering Consultant
35+ Years of Experience in Industrial, Offshore, and Infrastructure Projects

www.elreedyman.com

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]]> Corrosion in Reinforced Concrete Structures — Causes, Assessment, Repair, and Remaining Service Life https://elreedyman.com/corrosion-in-reinforced-concrete-structures-causes-assessment-repair-and-remaining-service-life/?utm_source=rss&utm_medium=rss&utm_campaign=corrosion-in-reinforced-concrete-structures-causes-assessment-repair-and-remaining-service-life Thu, 28 May 2026 11:25:37 +0000 https://elreedyman.com/?p=83112 One of the most common questions in structural engineering is: Why do steel bars corrode inside reinforced concrete structures? Every […]

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One of the most common questions in structural engineering is:

Why do steel bars corrode inside reinforced concrete structures?

Every year, billions of dollars are spent worldwide on repairing deteriorated concrete structures affected by reinforcement corrosion. Understanding the root causes of corrosion is essential for engineers, consultants, inspectors, and asset owners involved in structural assessment and rehabilitation.

In my technical publications and engineering courses, I discuss the science and practical engineering aspects of corrosion in reinforced concrete structures, including:

  • Causes of reinforcement corrosion
  • Concrete deterioration mechanisms
  • Structural assessment methodologies
  • Repair and strengthening techniques
  • Remaining service life prediction
  • Reliability and structural integrity evaluation

The detailed discussion is presented in my books available at:

Steel Reinforced Concrete Structure Assessment and Repair of Corrosion
and
Causes of Corrosion and Concrete Deterioration

Both books are available through my publications page:
https://elreedyman.com/publications/

Understanding Corrosion in Concrete Structures

Corrosion can be studied from two main perspectives:

  • Chemical reactions
  • Electrochemical and electrical theories

In this work, I combine both approaches from a practical engineering point of view. Engineers ultimately need practical solutions, but understanding the corrosion mechanisms is critical before selecting the appropriate repair strategy.

The most common causes of reinforcement corrosion include:

  • Chloride attack
  • Carbonation
  • Sulphate exposure
  • Aggressive environmental conditions

These agents may originate from:

  • Marine environments
  • Contaminated soil
  • Groundwater
  • Construction materials
  • Industrial exposure

The propagation of carbonation and chloride diffusion inside concrete can be predicted using engineering models and mathematical equations. These methods help estimate:

  • Corrosion initiation time
  • Cracking and spalling of concrete cover
  • Remaining structural service life

“Do Not Jump to the Conclusion”

One of the most important principles in structural assessment is:

“Do Not Jump to the Conclusion”

Before starting any repair work, a detailed structural assessment must be performed to identify the real root cause of deterioration.

For example:
If corrosion is caused by chlorides, it is essential to determine whether the chlorides originated:

  • from outside the concrete, or
  • from within the concrete mix itself.

The repair strategy and cost can vary dramatically.

In some cases:

  • External chloride contamination may require relatively economical repair methods.
  • Internal chloride contamination may increase repair costs by 10 to 50 times.

This is why proper condition assessment is always the first and most critical step.

Service Life of Concrete Structures

The time required for corrosion to initiate varies significantly from one structure to another depending on:

  • Design quality
  • Construction practices
  • Concrete quality control
  • Environmental exposure
  • Maintenance history

With good construction quality and proper environmental conditions, many concrete structures can remain in service for more than 60 years before significant corrosion begins.

Predicting the remaining lifetime of a structure is a complex engineering task that depends on:

  • Structural reliability
  • Durability performance
  • Inspection results
  • Exposure conditions
  • Maintenance and repair history

Repair or Replacement?

Another important engineering question is:

Is repair really necessary now?

Or:

Can the repair be delayed until funding becomes available?

The answer depends on:

  • Structural reliability
  • Structural system behavior
  • Method of construction
  • Design code requirements
  • Consequences of failure
  • Risk assessment

This concept forms part of the modern approach known as:

Structural Integrity Management

In many cases, the economic evaluation also becomes important. As a general engineering rule of thumb:

If repair costs exceed approximately 75% of the replacement cost, constructing a new structure may become the better option.

Learn More Through My Books and Engineering Courses

If you are interested in:

  • Structural durability
  • Corrosion engineering
  • Concrete assessment
  • Offshore structure reliability
  • Structural integrity management
  • Repair and strengthening techniques

You can explore my engineering books and online professional courses available through:

Publications:

https://elreedyman.com/publications/

Udemy Engineering Courses:

https://www.udemy.com/user/mohamed-a-el-reedy/

These resources are designed for:

  • Structural engineers
  • Civil engineers
  • Consultants
  • Asset integrity engineers
  • Researchers
  • Engineering students
  • Offshore and industrial professionals

If you have technical questions, engineering challenges, or special structural assessment cases, feel free to contact me.

Dr. Mohamed A. El-Reedy
Structural Engineering Consultant
Expert in Structural Reliability, Corrosion, Offshore Structures, and Integrity Management

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]]> Understanding Live Loads in Parking Garages: What About Electrical Car https://elreedyman.com/understanding-live-loads-in-parking-garages-what-about-electrical-car/?utm_source=rss&utm_medium=rss&utm_campaign=understanding-live-loads-in-parking-garages-what-about-electrical-car Mon, 09 Mar 2026 19:36:14 +0000 https://elreedyman.com/?p=82904  Introduction When designing parking garages, accounting for live loads is essential. The required live load values differ greatly depending on […]

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 Introduction

When designing parking garages, accounting for live loads is essential. The required live load values differ greatly depending on whether the structure serves passenger vehicles or heavier vehicles, such as trucks and buses. In this article, we will explore how design live loads are calculated and touch on the potential influence of electric vehicles on parking garage design considerations.

Live Loads for Passenger Vehicle Garages

For parking garages designed for passenger vehicles—including cars, SUVs, and pickup trucks with a gross vehicle weight rating up to 44.5 kN—the 2024 International Building Code (IBC) specifies a minimum uniformly distributed live load of 1.9 kN/m² (Table 1607.1). This load generally cannot be reduced under the code’s live load reduction provisions, except for vertical members supporting two or more floors, where a reduction of up to 20% is allowed. The same minimum live load is also specified in ASCE 7-22 (Table 4.3-1). Historically, prior to ASCE 7-02, passenger vehicle garages required a uniformly distributed live load of 2.4 kN/m², subject to reduction. In ASCE 7-02, this was reduced to 1.9 kN/m² non-reducible, based on a 2001 study by Y. K. Wen at the University of Illinois at Urbana-Champaign.

ASCE 7-02 Commentary Section C4.8.3 explained that:

  • “…Compared with the design live load of  2.4 kN/m2 given in previous editions of ASCE 7, a 1.9 kN/m2 live load represents a 20% reduction but is still 33% higher than the  1.4 kN/m2 one would obtain were an area-based reduction to be applied to the  2.4 kN/m2 value for large bays.”

Both the 2024 IBC and ASCE 7-22 account for concentrated loads in addition to uniform loads. While these concentrated loads usually don’t control the design, engineers should always check whether they could be critical in specific situations.

  • For garages designed for passenger vehicles carrying up to nine passengers, a single concentrated load of 13.3 kN acting on an area of 112.5 mm × 112.5 mm must be considered. This load simulates the force applied by a jack when changing a tire on a single vehicle. The load should be positioned to produce the maximum effect on the structural member under consideration. In some cases, this concentrated load may govern the punching shear design of garage slabs or the flexural design of double-T sections, particularly when applied near the end of the flange.
  • For mechanical parking structures without slabs or decks, designed to store passenger vehicles only, a concentrated load of 10 kN per wheel must be applied.

Designing Parking Garages for Heavy Vehicles: Live Load Requirements

For garages accommodating heavy vehicles—those with a gross vehicle weight rating over 44.5 kN, including trucks, buses, fire trucks, emergency vehicles, forklifts, and other movable equipment—live load requirements are provided in Section 1607.8 of the 2024 IBC.

Structural elements or areas where heavy vehicles may be driven must be designed using vehicular live loads in accordance with locally adopted codes for roadway and bridge design, such as the AASHTO LRFD Bridge Design Specifications. Section 1607.8.1 of the 2024 IBC also requires consideration of impact and fatigue effects in these cases.

However, for structures intended solely for parking heavy vehicles, such as dedicated heavy vehicle garages, impact and fatigue design is not required (Section 1607.8.3). Additional guidance is provided in ASCE 7-22 Commentary Section C4.10.2.

  • …For heavier trucks and buses, the vehicular live loads in the AASHTO LRFD Bridge Design Specifications (AASHTO) are to be applied. The AASHTO provisions for fatigue and dynamic load allowance are not required to be applied as the vehicle speeds in garages and vehicle storage areas are much lower than typical highway speeds.

Electric Vehicles and Parking Garage Design: How Live Loads Are Affected

The rise of electric vehicles (EVs), which made up over 10% of U.S. passenger vehicle sales in 2024, has raised questions about whether current parking garage live load standards are sufficient. While EVs are still under 2% of vehicles on the road, their heavier weight—similar to the trend toward SUVs and pickups—could affect load assumptions. Ongoing research, including a new study funded by the Charles Pankow Foundation, is examining how increasing EV adoption may influence parking garage design.

A major concern regarding electric vehicles (EVs) is the risk of fire caused by battery thermal runaway. Thermal runaway is an uncontrolled, self-heating process in which a battery’s temperature rises rapidly, potentially resulting in fire or explosion. Fires involving EVs have proven to be more difficult to extinguish than those in traditional internal combustion engine vehicles. Research by the Fire Protection Research Foundation indicates that while EV fires may develop more slowly and do not reach the same peak intensity, they tend to burn for much longer durations. It may take several years before any recommendations arising from ongoing structural and fire safety research are adopted as mandatory building code requirements.

Reference:

 (https://www.structuremag.org/article/electrical-vehicles-and-parking-structures/) 

  • Wen, Y.K, and Yeo, G.L.. Design Live Loads for Passenger Cars Parking Garages. Journal of Structural Engineering,  Mar 2001 280-289

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]]> Wind Load Calculation for Temporary Structures https://elreedyman.com/how-to-calculate-wind-load-in-temporary-structure/?utm_source=rss&utm_medium=rss&utm_campaign=how-to-calculate-wind-load-in-temporary-structure Tue, 27 Jun 2023 21:06:05 +0000 https://elreedyman.com/?p=82150 As per my last project an aluminum helideck over the highest tower in Alamain-North coast, I go deeply in wind […]

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As per my last project an aluminum helideck over the highest tower in Alamain-North coast, I go deeply in wind load charactristic. On the mean time, there are a lot of advertsing  board panel fall due to high wind speed in Cairo. So ifind it is mandatory to start my webinars and online courses about wind load calculation.

The main challenge  is a temporary structure due to their short design life compared to regular structures, it is expected that the temporary structures would be less likely to be subjected to the design wind speeds specified in ASCE 7.  Most of codes like ASCE, BS and EC excepet API for offshore structure consider the high 3 second wind speed for 50 years; so if the temporary structure life is  days, weeks or even months it should be less than the permenanat structure 

According to Gorlin (Journal of Architectural Engineering, ASCE, June 2009, pp.35-36), “Temporary structures encompass a wide range of items such as concert and theatrical stages, tents, public art projects, temporary roofs and shade structures, lighting and speaker towers, temporary grandstands and bleachers, and many other facilities.” However, there is no nationally recognized standard specifying design wind loads for such structures.

The 2015 IBC addresses temporary structures only superficially in its Section 3103. This section applies to structures erected for a period of less than 180 days, excluding tents and other membrane structures. However, nothing is mentioned on how to determine the design loads on such a structure except for a generic statement that “Temporary structures and uses shall conform to the structural strength, fire safety, means of egress, accessibility, light, ventilation and sanitary requirements of this code as necessary to ensure public health, safety and general welfare.”

In the absence of any clear requirements or guidelines, it is important to go through another standard: ASCE 37, Design Loads on Structures during Construction. ASCE 37 incorporates provisions for adjusting wind loads to reduce them for short-term exposure during construction for up to five years. This document provides the following reduction factors for the design wind speeds given in ASCE 7 based on the duration of construction.

Construction Period

Factor

Less than six weeks

0.75

From six weeks to one year

0.8

From one to two years

0.85

From two to five years

0.9

 

As per Another document that discussed  the temporary structures is one of the Unified Facilities Criteria (UFC) documents issued by the U.S. Department of Defense – UFC 1-201-01 dated 1 January 2013, Non-Permanent DoD Facilities In Support Of Military Operations. In this UFC, Non-permanent facilities are broken down into three construction levels: Initial, Temporary, and Semi-permanent. The levels of construction are based on life expectancy of the facility. This reasech done by S.K.Ghosh

Initial facilities are set up on an expedient basis with minimal external engineering design support. For construction, service, host nation, or contracted equipment and systems are used. Common facility types include tents, containers, and fabric shelters.

Temporary buildings and facilities are designed and constructed to serve a life expectancy of five years or less using low-cost construction.

Semi-Permanent buildings and facilities are designed and constructed to serve a life expectancy of less than 10 years. With maintenance and upkeep of critical building systems, life expectancy of facility can be extended to 25 years.

According to this UFC, it is permissible to multiply the basic wind speed, V, as applicable to a permanent structure, by a reduction factor of 0.78 for structures that meet the definition of temporary construction except in regions defined as Hurricane Prone Regions.

There is another code that is focused on entertainmenet event like a temporary concert stage roofs that considers the limited duration of exposure and human factors. This standard, developed by ANSI and Entertainment Services and Technology Association (ESTA) is ANSI E1.21, titled: Temporary Ground-Supported Overhead Structures Used to Cover the Stage Areas and Support Equipment in the Production of Outdoor Entertainment Events. This ANSI document specifies the design wind speed to be 0.75 times the basic wind speed defined in ASCE 7.

Engineers should use his common sense approach to more significant engineered structures and also incase of taking the loads combinations as it is different from one structure to another. keep in mind how to minimize the risk on the same time have an economic structure.

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]]> Reliability for USA Bridges https://elreedyman.com/reliability-for-usa-bridges/?utm_source=rss&utm_medium=rss&utm_campaign=reliability-for-usa-bridges Thu, 17 Dec 2020 08:25:21 +0000 https://elreedyman.com/?p=24143   The average bridge in USA is now 43 years old. According to the U.S. Department of Transportation, of the […]

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The average bridge in USA is now 43 years old. According to the U.S. Department of Transportation, of the 600,905 bridges across the country as of December 2008, 72,868 (12.1%) were categorized as structurally deficient and 89,024 (14.8%) were categorized as functionally obsolete.

From 2005–2008, the number of deficient (structurally deficient plus functionally obsolete) bridges in rural areas declined by 8,596. However, in urban areas during the same time frame, there was an increase of 2,817 deficient bridges. Put another way, in 2008 approximately one in four rural bridges were deficient, while one in three urban bridges were deficient. The urban impact is quite significant given the higher level of passenger and freight traffic.

A structurally deficient bridge may be closed or restrict traffic in accordance with weight limits because of limited structural capacity. These bridges are not unsafe, but must post limits for speed and weight. A functionally obsolete bridge has older design features and geometrics, and though not unsafe, cannot accommodate current traffic volumes, vehicle sizes, and weights. These restrictions not only contribute to traffic congestion, they also cause such major inconveniences as forcing emergency vehicles to take lengthy detours and lengthening the routes of school buses.

With truck miles nearly doubling over the past 20 years and many trucks carrying heavier loads, the spike in traffic is a significant factor in the deterioration of America’s bridges. Of the more than 3 trillion vehicle miles of travel over bridges each year, 223 billion miles come from trucks.

To address bridge needs, states use federal as well as state and local funds. According to the American Association of State Highway and Transportation Officials (AASHTO), a total of $10.5 billion was spent on bridge improvements by all levels of government in 2004. Nearly half, or $5.1 billion, was funded by the Federal Highway Bridge Program—$3.9 billion from state and local budgets and an additional $1.5 billion in other federal highway aid. AASHTO estimated in 2008 that it would cost roughly $140 billion to repair every deficient bridge in the country about $48 billion to repair structurally deficient bridges and $91 billion to improve functionally obsolete bridges.

Simply maintaining the current overall level of bridge conditions that is, not allowing the backlog of deficient bridges to grow would require a combined investment from the public and private sectors of $650 billion over 50 years, according to AASHTO, for an average annual investment level of $13 billion. The cost of eliminating all existing bridge deficiencies as they arise over the next 50 years is estimated at $850 billion in 2006 dollars, equating to an average annual investment of $17 billion.

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]]> How to Calculate Offshore Structure Probability of Failure https://elreedyman.com/how-to-calculate-offshore-structure-probability-of-failure/?utm_source=rss&utm_medium=rss&utm_campaign=how-to-calculate-offshore-structure-probability-of-failure Fri, 14 Aug 2020 20:36:22 +0000 https://elreedyman.com/?p=15815 Most of the owner companies are focus about the integrity of its facilities and specific of its platform which is […]

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Most of the owner companies are focus about the integrity of its facilities and specific of its platform which is the major asset. The structure integrity management present the structure reliable along its lifetime which required to calculate its probability of failure and to have a criteria for the reliability index or the probability of failure based on the consequence in case of failure.

There are many researches and development know to define the structure probability of failure which is the reverse to the definition of the structural reliability. The offshore structure reliability analysis (OSRA) are often required in the reassessment of existing structures; this is particularly the case for fixed platforms which would experience wave-in-deck loading at high return periods. An OSRA allows the risk of platform failure to be quantified and the effect of any measures to mitigate the consequences to be understood. A key input into this analysis is the metocean loading in extreme conditions. Another is the probability of those conditions occurring. 

There are mainly two methods to define the structure reliability and its probability of failure are the first order reliability meth of (FORM) second order reliability method(SORM) or simulation by using Mote-Carlo simulation technique. Most of the researches are going to use second moment methods as they can calculate the variability of load and resistance.

In DnV report (1995) was used second moment method but the report used four limit state  equations which are Ultimate limit state (ULS), which present  danger failure like inelastic member, free drifting or sinking of the structure in case of tension leg platform (TLP.) and Fatigue limit states(FLS), which present the failure due to cyclic loading as in case of fatigue in the joint, Collapse limit state (CLS) which present a complete collapse in abnormal effect and also the serviceability limit state (SLS) which present the failure to do its function under the normal condition.

Another method, which is used in recent years, is the one proposed by Ersdal (2005). Ersdal in his thesis proposed a simple probabilistic model including a relation between the RSR indicator and the annual failure rate for existing structures installed in the North Sea in shallow or intermediate water depth. In this study, wave load was calculated in terms of the annual maximum wave height with probability of exceedance equal to 10-2. The annual maximum wave height was also assumed to follow a Gumbel distribution. The ultimate capacity was assumed to be equal to the calculated wave loading multiplied by the RSR using the equation UCR = RSR × (C1x H100 C3) in which RSR is the Reserve Strength Ratio, C1 xH100 C3 is assumed to be the design loading. C1 and C3 are the load coefficients that have to be extracted from a curve fitted to the results of load calculation. Probability of failure is then estimated using Monte Carlo approach based on the total number of simulations and the number of samples falling into the failure domain.

 The relationship between the RSR versus annual probability of failure has also been established as Pf = 10-0.0886-1.9976 RSR     it is also important to note that there is some limitation in this study and some possible hazards like corrosion and pile related failure mode have not been included.

 

More reseraches in this topics and its application practically is presented in this book.

 

There are a recent  researched in 2006 and 2007  focused on the calculation of the probability of failure such as studies on seasonal storms in the GoM. In these studies performance of fixed steel jacket platforms in Katrina and Rita has been assessed.

However, some researches do the simulation but also considered these two variables only so the benefit of the simulation is not obtain. As by using simulation we can present the variability for each element which is very complicated and factors which is very complicated to be done in case of the offshore structures.

Therefore most of researches define the variability on the load and present the wave by its statistical parameters and some of other considered resistance and load as probabilistic and all other factors are deterministic.

As an ideal case which provide us more accurate and need further research and development is to consider all the variables and us the simulation and there will be an integration between the simulation by using monte-carlo like crystal ball software or B-risk and the offshore structure analysis by SACS in this case it is required to run SACS software for at least 10,000 times as discussed in the above section.

 As presented in the  book a new approach by software development to connect monte-carlo with the offshore structure analysis package. It will be costly but it is the actual case to calculate the offshore structure probability of failure.

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]]> Comparison Between Project Management and Operations https://elreedyman.com/comparison-between-project-and-maintenance-organization-and-culture/?utm_source=rss&utm_medium=rss&utm_campaign=comparison-between-project-and-maintenance-organization-and-culture https://elreedyman.com/comparison-between-project-and-maintenance-organization-and-culture/#respond Tue, 03 Dec 2019 17:55:11 +0000 https://elreedyman.com/?p=4256 As the concept of a project differs fundamentally from that of daily or routine operations and maintenance, it follows that […]

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As the concept of a project differs fundamentally from that of daily or routine operations and maintenance, it follows that a number of principles and conceptions of project management must also diverge from those followed in the realm of maintenance management.
In maintenance management, tend generally to focus on maintain the facilities reliability during its lifetime production.

Project management may be defined as the planning, organization, direction, and control of all kinds of resources in a specific time period for achieving a specific objective comprised of various financial and non-financial targets.

This should help clarify the difference in outlook of the project manager and the maintenance manager. The project manager’s goal is to finish the project on time. Then he evaluates where he will relocate after finishing the project. The maintenance manager, on the other hand, never wants daily production to stop, and cannot dream of work stopping as distinct from the project manager’s goal of overall task completion.
The challenge here is in case of major rehabilitation project which is the major maintenance project and it called also “brown field” project. So my question; Are the engineers in engineering or construction phase in brown field project can have the same competency as the new project “green field” project?

Sure No as the attitude is different but it is easy to learn with time. The maintenance engineers usually work in existing facilities so the repair concept in his mind so his plan and vision and attitude is flexible to have a fast action if some thing happened. His experince and vision assist him to predict what is expected to happen rather than the project engineer he is more organize and always thinking about his scope borders and prepare himself to the scope only. Really this difference is not an easy as the project engineer need to think about. On the otherside for the maintenance engineer require to switch to project engineer he should be more organized and restrrict him to the project scope definition and define its border clearly he should tailored himslef about it.

There are big contractor firm in middle east performed a lot of mega projects from long time but fail in implementing maintenance contract due to bad performance and he loose a money  until the owner fire him. Can you imagine that as it is not only a person but also the organization if it is capable to switch from green field project to regular maintenance or not. It is not the engineer only we consider about the PSCM system and adminstration system also.

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]]> https://elreedyman.com/comparison-between-project-and-maintenance-organization-and-culture/feed/ 0 Protecting Steel Reinforcement from Corrosion https://elreedyman.com/protecting-steel-reinforcement-from-corrosion/?utm_source=rss&utm_medium=rss&utm_campaign=protecting-steel-reinforcement-from-corrosion https://elreedyman.com/protecting-steel-reinforcement-from-corrosion/#comments Sun, 20 Oct 2019 12:58:04 +0000 https://elreedyman.com/?p=3230 The most frequent questions, I got asked  in all of my lecturers  is how to protect the steel bars, the […]

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The most frequent questions, I got asked  in all of my lecturers  is how to protect the steel bars, the second one is how to repair the concrete structure members. 

First let me ask you a question, Can the Doctor Provide you with the appropriate  Medicine  before Diagnosis  your case?

If your answer is NO, then you are certainly aware that you must have have a strong background about this problem and study it  well..Then, start to preparing the action plan and the required steps to get it in perfect way.

Therefor, the first step you should understand very well the Corrosion Phenomina and then the Causes of the Corrosion and the different between them, as it is described in brief in last two articles.
The choose of the best type of the protecting the steel reinforcement depends on your structure system, your structure life time and also the environmental condition surrounding the structure and the expected cause of corrosion. We can use one or two method in the same time or we can use nothing. These methods as:
  • Use Anodic inhibitor
  • Coating steel bars by epoxy

  • Using zinc coating
  • Replacing steel bars by FRP for more data you can visit this website www.tuf-bar.com  they have a valuable data with the project done by using FRP.

Reinforcing steel mesh, close up image of construction material.

  • Cathodic protection painting
  • Cathodic protection system
All these methods are illustrated in detail in the ebook, Methods of Protecting Steel Reinforcement from corrosion, please on the comment ask for your code to download the ebook. The ebooks series there are a references list, at the end if any one need a further reading or assist him/her in his/her research. 
Every method has its advantages and disadvantages, that should be known before take decision to apply it or not. For example cathodic protection with impressed current request an electrical source near to your structure if you are in remote area it will not be  practical option and so on. The other main factor which is the criticality of the structure it is mean that a risk analysis should be done by defining the consequence in case of the structure failure or need a major maintenance . On the other side to obtain the probability of occurrence failure of the structure or required a  major maintenance. In addition to that the cost of each system and its reliability for example  CP system has a higher cost but can withstand for over 60 years without any major maintenance.

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]]> https://elreedyman.com/protecting-steel-reinforcement-from-corrosion/feed/ 2 CONCRETE STRUCTURES REPAIR https://elreedyman.com/concrete-structure-repair/?utm_source=rss&utm_medium=rss&utm_campaign=concrete-structure-repair https://elreedyman.com/concrete-structure-repair/#comments Sat, 31 Aug 2019 13:37:19 +0000 https://elreedyman.com/?p=2100 For mature reinforced concrete structure, there is always a cracks appear that make the owner or who are using the […]

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]]> For mature reinforced concrete structure, there is always a cracks appear that make the owner or who are using the building  afraid to live on it.

Then you need to do some repair for this structure to be safe in use. The first step usually is to do a site visit to see what is the cracks shape and nature, PLEASE in this stage and specific for junior engineers advice this statement should be in your mind. “DO NOT JUMP TO THE CONCLUSION”. As the engineers is happy to tell the people that he has a solution in their problem to be self satisfaction. But please take care and take your time by collecting the required data and then define the solution after studying in the office with a cup of coffee and take time of thinking. I know that, they are always pushing you to provide a solution during your site visit, but you should be professional in dealing with it.

Mature structure like an old man when he goes to the doctor, can you imagine if the doctor diagnosis is wrong, so the medicine shall be wrong. The result is DEATH. This is the same situation as we face in the old building. The treatment should be match with his existing condition same as in our case. The repair procedure you can find it in any text book but the challenge is to choose the best method to your structure

Even in case of corrosion as its repair procedure is known and easy, but you should know the reason of the corrosion as there are many reason, as it may be due to carbonation, chloride and even in case of chloride attack it should be defined if it is from outside or inside. Some times it will be  from bacteria as in case of foundation.

The type of epoxies and repair procedure is varied depending on diagnosis to define the reason of that cracks. The repair procedure  depends on the as-is-condition of the structure itself; in some cases the structures was failed during the repair.

It is very important to study and do your calculation precisely based on the collected information about the building to define the location of the temporary supports. As you need to define the load path of the load and do some sort of risk assessment if any of the element fail.

There are many ways of repair which are summarized in these 4 methods:

  • Traditional method

In this method we can add steel reinforcement or not add more steel depend on the remaining diameter of the steel bar as a rule of thumb if the reduction is more than 20% it is mandatory to add steel bars.

  • Using epoxy injection method

This technique is used to fill the cracks in the wall and also it can be used with CFRP to close the cracks on the wall from opening. This methods should be applied by higher professional team to have a good repair.

  • Using strengthening by steel sections

This method is very fast by using steel sections and plates to fix the concrete member or increase its strength; as example in the below photos but the thickness of the member will increase and you need some decoration and finishing scenario to cover its ugly shape.

 The CFRP can be used in repair and also in strengthening for any members based on some constrain and the design of CFRP is follow ACI 440.

The old method of strengthening is to use hot rolled sections but its applications is not  reliable and it increases the member thickness however CFRP its thickness measure by mm so there is no increasing in member dimensions, and it is not easy in application but it need a professionalism during the application.

These methods of repair are described in detail in this link.

The best repair method shall be defined based on the good assessment. At the END ” DO NOT JUMP TO THE CONCLUSION“

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]]> https://elreedyman.com/concrete-structure-repair/feed/ 9 Risk Assessment For Oil and Gas Project https://elreedyman.com/risk-assessment/?utm_source=rss&utm_medium=rss&utm_campaign=risk-assessment https://elreedyman.com/risk-assessment/#comments Wed, 14 Aug 2019 20:41:57 +0000 https://elreedyman.com/?p=1744 Risk assessment can be used in many ways. In oil and gas construction activity focus about the safety risk assessment […]

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Risk assessment can be used in many ways. In oil and gas construction activity focus about the safety risk assessment , which in general is qualitative. The other view of the risk assessment is to do for business or the projects in general. For business it can be used in Economic study. For the project management it can be used in cost estimation to define the contingency value and in probabilistic schedule plan which is discussed in many text book as PERT method  which depends on the probability of activity duration.

 
 
 
 
 
There are many methods can be used to calculate the probability of occurrence but the most traditional method and can be used practically is  Monte-Carlo simulation technique. This method can be used also in calculating the structure probability of failure or structure reliability as per the discussion in How to predict the structure failure?

There are many software’s that are based on Monte-Carlo simulation, the best one is the Crystal-ball software.

The idea of Monte-Carlo is very easy, but it needs more knowledge and care in defining the probability of the input data as presented in the above video which is discussed in detail in project management for oil and gas eLearning.

This video presents the economic study for oil and gas development project and how to calculate the net present value (NPV) to evaluate the project risk and to assist in take decision on the project Go/No Go.

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