How Do You Get a Copy of the New GSA Blast Document?

We are often asked how do you get a copy of the new General Services Administration Facility Security Requirements for Explosive Devices Applicable to Facility Security Levels III and IV: GSA’s Interpretation of the Interagency Security Committee (ISC) Physical Security Criteria? 

You asked…we answered!

Why Bother With Site Visits? Because They Are Critical!

When writing an RFP for a Blast Vulnerability Assessment there are a number of things to consider, one of which is whether to pay for the engineers of the assessment team to visit the site in person.  Often, the inclination may be to reduce the cost of the assessment by excluding a site visit.

We do not recommend this approach, as it limits the ability of the assessment team to develop feasible, effective solutions tailored to the requirements of the specific buildings and compounds.

No matter how much information may be available about the buildings and structures, it is rarely as much as is thought and it is no substitute for the engineer-assessors seeing the building and compound for themselves.

Typical Site Visits

Site visits will vary based on the previously available information, the number and complexity of the buildings, the threat-types to be assessed, and the location of the project.    At a minimum, the following should be included:

• Meeting with the Security Staff to identify security concerns, critical areas of the compound, local risks associated with the everyday function of the compound, etc.
• Meeting with the Operational and Maintenance Staff to identify limitations on modifications to the building and compound.  Limitations could include a need to maintain operability of windows, size of trucks requiring entry to the compound, etc.
• Visual evaluation of the compound configuration and surrounding area to evaluate possible non-hardening measures which can be easily implemented to provide protection to building occupants (increase standoff distance, layout and entrance orientation to minimize speed of vehicular approach, etc.)
• Visual evaluation and non-destructive Investigation of the existing structures under consideration and comparison with existing drawings to validate the information required to perform the blast vulnerability assessment of the existing structures.
• Review of the local construction environment in order to understand local contractor skill sets, material availabilities and typical construction approaches.

Destructive Investigation

When there is limited information available regarding the existing building construction and configuration, or when the validity of the information may be suspect (i.e. in countries where there is no established building code and inspection process), destructive testing and investigation may be advisable.    This testing could include:

• Cutting and removing physical samples of concrete, masonry or steel elements of the building for testing by a laboratory.
• Using electronic meters to map reinforcing locations and patterns in masonry and concrete structures.
• Selective removal of concrete or masonry to determine the size of reinforcing bars.
• Removal of architectural finishes to inspect connections between structural members.

What The Heck Is Balanced Design??

If you have been involved with a project that includes blast loads, you have probably heard of “Balanced Design.”   If the project had more than one blast consultant, you probably heard way more about Balanced Design than you ever wanted to hear.  This is because there is no single approach to incorporating it into a project.   So….the million dollar question is:  What the heck is Balanced Design?

Balanced design is a concept commonly used in blast and earthquake engineering that refers to designing supporting elements to the ultimate strength of the supported elements.

The key is to create structural fuses (just like an electrical fuse) designed to be a point of safe failure that will limit damage from a larger than design blast (or earthquake) from cascading to larger and larger areas.

In earthquake engineering, a typical application of this concept is the “strong column/weak beam” concept required in high seismic zones.  This requirement was instituted to avoid catastrophic failure by forcing the beam to fail before a column in case of a larger than design seismic load.  While there would still be a failure, the result of the failure would be less extensivethan if the column failed.

From a blast perspective, balanced design can be applied to both structural and non-structural elements.  There are several ways to achieve balanced design:

• Vary the allowable response limits of elements based on their importance. For instance, while a secondary beam would be designed to no more than heavy damage, its supporting girder would need to be designed to allow only moderate damage. While this approach meets the intent of balanced design, when the overall design is not controlled by blast forces, the final structural system may be unbalanced.
• Design supporting elements to develop the static capacity of the supported elements. While this approach always results in a balanced system, it can result in a highly conservative design as this approach does not include the dynamic response of the system.
• Design the entire load path to the dynamic capacity of the first element loaded. While this approach results in a more precise solution, there are several issues related with the definition of failure of this first element and the associated time-history load.  When using this approach, project stakeholders should agree on definitions and approach prior to commencing analysis.

Balanced Design acknowledges that it is difficult to precisely predict the magnitude of an earthquake or the size of a blast, and it is therefore important to create a controlled failure mechanism to limit the extent of damage.

Presenting….iStandoff a Stone Security Engineering iPad App!

Stone Security Engineering is thrilled to present a great new tool for design teams and security personnel who work on DoD projects incorporating the requirements of the updated UFC 4-010-01 DoD Minimum Antiterrorism Standards for Buildings.

iStandoff  is a free iPad App that has been designed to quickly and easily identify Conventional Construction standoff distances, per the UFC 4-010-01 DoD Minimum Antiterrorism Standards for Buildings, dated February 9, 2012.

Background

As mentioned in the April edition of this Industry Briefing, the Conventional Construction standoff distances “now depend not only on the required level of protection, but also on the exterior envelope construction type, and structural function (load bearing vs. non-load bearing.”

In order to determine the project specific Conventional Construction two tables (Table B-1 and Table B-2) need to be cross-consulted. (The table shown in the application is a reproduction of Table B-1: Standoff Distances for New and Existing Buildings from the UFC document).

The App

This Application automates the process of determining Conventional Construction standoff distances and provide the applicable distances with two taps of the screen.

Additional Services

Note that all wall types are not included in the tables in the UFC document.  If your project has construction configurations not covered, Stone Security Engineering provides design services that will assist you in determining the requirements for your specific situation.   Contact us at Info@StoneSecurityEngineering.com or at +1(646) 649-3169.

Available from the Apple Store

What’s New for Windows? Updated UFC 4-010-01 Minimum Antiterrorism Standards For Buildings

One area of changes in the New UFC 4-010-01, 9 February 2012, is in the design requirements for exterior windows and skylights.   The updates are pretty exciting, from this blast engineer’s perspective, because they explicitly address some of the recurrent questions from design teams and owners, and clarify items that seemed to have differing interpretations, depending on who was doing the interpreting.  Well done PDC!

Historically, exterior windows and their supports, have been one of the primary areas where application of the UFC 4-010-01 has added costs to projects, so any changes to window requirements should be of the utmost interests to design and construction teams, developers, and building owners.

Here are some of the changes that affect exterior windows:

• Standoff Distances for Window Design:   The updated UFC now requires that all exterior windows and skylights be designed for explosive weights I and II located at the actual standoff provided.   A caveat to this is that explosive weight II is waived for window design if the standoff exceeds 200 feet.   This is a big change from the previous version of the UFC, which required that windows be designed for the conventional construction standoff distances, even if the project had larger standoffs.    So….buildings with larger standoff distances could benefit from significant load reductions – which should hopefully translate to cost savings – under the new UFC.
• Analytic Approach:   One of the really useful updates to the document is reference to a new PDC document – PDC-TR 10-02 Blast Resistant Design Methodology for Windows Systems Designed Statically and Dynamically, 19 April 2012 – which provides detailed guidance on the static and dynamic analysis approaches for window systems.  Including dynamic response limits for frames and mullions, appropriate probability of failure for different glass types, design examples, and the introduction of a new DoD software for designing glazed systems (SBEDS-W).  This will help provide consistency in design across DoD projects.   Note that Static Analysis is only allowed for Very Low and Low levels of protection, as   long as the threat size and standoff are covered by Figure 1 in ASTM 2248.
• Minimum Glass Lay-up Requirements:   The only minimum glass requirement is that the interlayer thickness must be greater than 0.030″.  There are no longer minimum thickness requirements for the glass itself.
• Frames and Connections:  When analyzed statically, window frame and connection designs are based on the glazing resistance and are not reliant on the applied load.  This may be useful for window vendors who are interested in being able provide off-the-shelf systems.  However, while this may be convenient to provide off-the-shelf solutions, design teams can still introduce significant savings by using dynamic analysis in projects,  especially projects with high wind and other protection requirements beyond blast.
• Frames:  Window and skylight frames can be designed statically for a load two (2) times the glazing resistance using LRFD with strength reduction factor equal to 1.0.
• Connections:  Connections between the window system and the surrounding wall are to be designed using LRFD with their applicable code reduction factor to meet the ASTM F2248 with a design load of  a) Two (2) times the glazing resistance if the peak dynamic pressure is larger than half (1/2) the glazing resistance, OR b) One (1) time the glazing resistance if the peak dynamic pressure is less than half (1/2) the glazing resistance.
• Window Supporting Elements:  The window supporting elements can be designed statically when the Conventional Construction Standoff Distance for the specific wall type is exceeded. Otherwise, the dynamic approach is required.   The PDC-TR 10-02 Section 4-2.9 also limits the applicability of the static approach to punched openings. Remember, this new version of the document has really shaken up the Conventional Construction standoff distances, and project teams will need to pay close attention to the application of this concept to their specific buildings.

Hopefully this helps in understanding how the updated UFC 4-010-01 will impact your projects.   If you would like additional information or guidance, give us a call at (646) 649-3169, or send us an email at info@StoneSecurityEngineering.com.

Considerations in Collapse Building Assessment for Rescue Environments

As much as we would like to think of buildings as inviolable, it is a fact of life that they can – and do – collapse.   In fact, a quick internet search shows the following collapses in the past six months:

• May 4, 2012:  Residential building collapse in Harlem, New York.
• April 16, 2012:  Factory building in Jalandhar, India
• March 23, 2012: Apartment Building, Alexandria Egypt
• March 18, 2012:  Building floor in NYC collapsed during a party
• January 26, 2012:  Three commercial buildings in Rio De Janeiro, Brazil
• January 16, 2012:  Residential Building in Beirut, Lebanon
• November 8, 2011:  Five story building under construction, Brooklyn, New York

Regardless of the cause (whether it be earthquake, explosion, high winds, snow overloads, or construction/design defects) the result is typically the same – a hazardous and confusing combination of steel, concrete, wood and other materials that needs to be searched to determine if there are any victims to be rescued.

An important aspect of responding to collapses is understanding the hazards of the debris pile and the remaining portions of the damaged building.  While there are many, many, considerations that must be carefully evaluated, this briefing focuses on just two:

• The remaining potential energy in the damaged structure.
• The stability of the remaining structure; from both a global and individual damaged element perspective.

Remaining Potential Energy.  Gravity works – and can be one of the main enemies of a safe and successful search and rescue operation.   The amount of potential energy in a structure, a portion of a structure or a hanging hazard, is based on how much weight remains and the height at which the weight is suspended.    For instance, a broken façade tile on the side of a damaged building has much more potential energy if it is located at the 10^th floor of a building than if it is located at the first floor of the building.    This potential energy translates to damage (or injury) that can occur when the object falls and the potential energy is released.

Stability.  In order for partially collapsed buildings and/or overhead falling hazards to pose a significant risk, they must have an element of instability – i.e. there has to be a chance that it will fall or move from its current location.

Stability is affected by the remaining capacity of the connections (for instance, the remaining capacity of the connection of the façade tile to the building wall shown in the picture above is almost non-existent), and the strength and redundancy of the remaining load path (i.e. the path of supporting elements that allow the weight of the structure to flow down to the ground).

Of the two photos below, the one on the right – that at first glance would appear to be hazardous –is, in fact, fairly stable since it is now supported by another building.   On the other hand, the building in the photo on the left, which has an apparently similar level of damage, is very unstable as there is no new load path to support the weight of the building.

The above are only two of many hazard assessment considerations.  Look for additional information on collapsed building assessments in our future Industry Briefings.

Information contained in this article is based, in part, on the USACE/FEMA Structures Specialist- II course.

Three Reasons to Choose Design-Build For Physical Security Projects

Historically, the most common method for constructing a new building or building improvements was what is known as Design-Bid-Build.   In this approach, the owner hires a design team to create a detailed set of drawings and specifications which completely describes what is to be constructed.  The owner then puts the project out to bid for construction, receiving and evaluating proposals from construction contractors.  Finally – once the owner has gone through the proposals, selected a contractor, and negotiated a contract – the construction can begin.   In many cases, the overall time from identification of need to completion of construction can be quite lengthy, especially for public and quasi-public agencies which have many contracting regulations that extend the bid and bid review process.

An alternative to this is the Design-Build approach.  The Design-Build Institute of America (DBIA) defines Design-Build as “a method of project delivery in which one entity – the design-build team - works under a single contract with the project owner to provide design and construction services.”     There are many varieties of design-build; from an RFP that basically says “I want a wall” to a much more rigorous approach (such as is often used by the US Government) where a set of drawings and performance specifications are developed to between 10% and 35% completion.   In between these two extremes is the “this is generally what I want” approach, which provides a rough sketch of what is wanted  with a list of the essential design requirements.

When talking about security improvement projects such as blast hardening, anti-ram barriers, forced entry/ballistic resistant elements, entry control points, etc; Design-Build can be the best approach to rapid, cost effective implementation.

Less Time.     This can’t be emphasized enough, the design-build approach will reduce the amount of time from identification of a security need to implemented protections – by orders of magnitude.   There are numerous reasons for this, which include:

• The owner only has to go through a single bidding process (this alone can take multiple months off project duration).
• Once the baseline design has been agreed to between the design-builder and the owner, building materials which may have long fabrication and delivery times can be ordered while the rest of the design is being completed.   This can be especially beneficial in remote areas where shipping can be measured in months rather than weeks, in countries where customs clearance regularly cause delays, and on projects that require specialty items (such as forced entry/ballistic resistant doors and windows) that have relatively few certified manufacturers.

Less Cost.     By combining the design and construction responsibilities into one entity (the design-builder), the design process becomes more efficient.   This happens because

• The engineers on the design-build team will be more precise in their design;  taking into account the local material and labor resources, the ease of construction of different solutions, variables such as weather and customs limitations, and potential phasing of the construction  process, and
• The engineers will also be able to create more ‘bare-bones’  set of drawings and specifications.  This is because they will be involved in the entire construction process and will be able to ensure that sub-contractors meet the requirements without describing each element in painstaking detail.

The designers in a design-bid-build scenario do not have control over who the contractor will be, what resources or specialties the contractor will have, or how the final construction phasing will take place and they can therefore not tailor the design to the actual circumstances as much as a design-builder.

Less Risk to Owner.    By having a single point of responsibility, the design-build approach reduces the risk of cost and schedule overruns and decreases the possibility of finger pointing between the contractor and the designer, which can happen in Design-Bid-Build projects when there are conflicts or omissions in the drawings.

While no project is perfect, and there will always be bumps in the road when it comes to construction projects, the Design-Build approach can lessen the effects of these and will provide implemented protection measures in a more timely and cost effective manner.

Field Guide for Building Stabilization and Shoring Techniques (BIPS 08/October 2011)

Stone Security Engineering is pleased to announce publication of a field reference guide for vertical shoring, lateral shoring, and rapid strengthening and/or repair of damaged building components.  This is an exciting project that provides detailed information for first responders and the engineers that support them.  The intended audiences of the guide include:

• First Responders:   Local agencies responding to initial/everyday incidents.    Engine companies, truck companies, police, etc.
• Special Operations and Technical Rescue Teams:  Department based units, companies or teams that have more specialized training and equipment than the First Responders.
• County and Regional Response Teams:  County and regional based teams with specialized training and equipment.
• State & National Response Teams (FEMA US&R and SUS&R teams):  Highly trained, advanced equipment.
• Disaster Engineers:  Trained engineers who may respond as a component of any of the above categories.

The guide refines and expands on the information provided in the existing US&R Structures Specialist Field Operations Guide (FOG) and includes a primer on what it means to stabilize a building in a post-disaster environment.

• Structural Hazards
• Risk Management
• Hazard identification, assessment and mitigation

It also includes detailed information on the current FEMA developed built-in-place shoring systems, newly designed and tested built-in-place shoring systems, the results of the most recent testing of built-in-place shoring systems, and a system by system discussion of the relevant characteristics of Manufactured Shoring and Repair and Strengthening techniques  that may be able to be adapted to rescue operations.

This document was produced under contract from the Department of Homeland Security, Science and Technology Directorate, Infrastructure Protection and Disaster Management Division through URS Corporation.  The authors included our own Hollice Stone, Dr Michael Barker, David Hammond, and John O’Connell.   All the authors have spent years in the FEMA and US Army Corps of Engineers Urban Search and Rescue programs.

GSA Facility Security Requirements for Explosive Devices Applicable to Facility Security Levels III and IV

Stone Security Engineering authored a new GSA blast standard that was approved and released in August 2011:  GSA Facility Security Requirements for Explosive Devices Applicable to Facility Security Levels III and IV. This document provides detailed criteria for implementing the blast and progressive collapse requirements of the ISC 2010 giving specific design and performance requirements for GSA facilities required to meet an FSL III or IV.

In general terms, the security measures implemented for both FSL III and FSL IV require a certain level of blast and progressive collapse hardening of the facility. In an FSL III facility, these security measures are, for the most part, prescriptive including while an FSL IV facility will need to meet more performance based requirements.

The document also provides updated guidance on balanced design for window systems, details of how to implement the modified standoff distance requirements in the 2010 ISC Physical Security Criteria (major change from the 2004 ISC Security Design Criteria), and detailed technical information to implement blast resistant design for GSA Level III and Level IV buildings.

This document is now being implemented on GSA and GSA related projects and it is important for project teams working and bidding on government work to understand the requirements.

NEW UFC 4-010-01 DoD Minimum Antiterrorism Standards for Buildings

The DoD has released a new UFC 4-010-01, dated February 9, 2012. Whenever there is a new version of this UFC, the industry experiences growing pains as they become familiar with the changes and nuances in the new document, and there are quite a few changes in this new version.    However, we see wanted to highlight two updates as being the ones that will have the most far-reaching effects or will cause/remove the most confusion in this time of transition between versions.  These are:

• Clarifications in the levels of protection, applicability and exceptions of the requirements.
• Significant changes in standoff distances.

Clarifications:

The standards in the UFC 4-010-01 are applicable to all DoD components, all DoD inhabited buildings, billeting, and high occupancy family housing, and all DoD expeditionary structures. The updated document includes needed clarification on the applicability of these standards. For example:

• Mandatory for all new construction (regardless of funding source) with the following caveats:
  • Projects programmed or designed under previous standards if design has proceeded past 35% completion (design-bid-build projects) or if the project has progressed past the RFP phase for Design-Build projects.
  • Projects funded by host-nation agreements upon completion of negotiations with the foreign government.
• Non-DoD Tenant Buildings on DoD Installations – are to comply with the new document.
• Enhanced Use Leases  – if facilities associated with Enhanced Use Leases are completely outside the installation controlled perimeters and where access to those facilities does not require access from within the controlled perimeter – the facilities are exempt (unless they meet the DoD occupancy limits)

Standoff Distances

In the previous version of the UFC 4-010-01, standoff distances depended exclusively of the required level of protection.  This new version introduces additional variables into the determination Conventional Construction standoff distances, which are based on blast calculations.   These now depend not only on the required level of protection, but also on the exterior envelope construction type, and structural function (load bearing vs. non-load bearing).   Therefore, in order to identify if air-blast design of the building is required, the design team needs to consider the specific type of construction as referenced in UFC 4-010-01 Table B-2 (including the limitations in Table 2-3) in order to identify the applicable Conventional Construction Standoff. For preliminary information, Stone Security Engineering has developed a spreadsheet that will help design teams identify the conventional construction standoff distances for their particular situations. This spreadsheet can be downloaded from the Resources Section.

Allowable minimum standoff distances have also changed to a minimum of 18 feet to the controlled perimeter or parking and roadways without a controlled perimeter, and 12 feet to parking and roadways within the controlled perimeter and trash containers. This new minimum standoff distances are substantially smaller and will have important implications in the design of buildings to support air-blast loads.