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Assessing, Coding, and Marking of Highway Structures in Emergency Situations, Volume 1: Research Overview (2016)

Chapter: Chapter 3 - Evaluation of Assessment Technologies and Coding/Marking Practices

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Suggested Citation:"Chapter 3 - Evaluation of Assessment Technologies and Coding/Marking Practices." National Academies of Sciences, Engineering, and Medicine. 2016. Assessing, Coding, and Marking of Highway Structures in Emergency Situations, Volume 1: Research Overview. Washington, DC: The National Academies Press. doi: 10.17226/24608.
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Suggested Citation:"Chapter 3 - Evaluation of Assessment Technologies and Coding/Marking Practices." National Academies of Sciences, Engineering, and Medicine. 2016. Assessing, Coding, and Marking of Highway Structures in Emergency Situations, Volume 1: Research Overview. Washington, DC: The National Academies Press. doi: 10.17226/24608.
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Suggested Citation:"Chapter 3 - Evaluation of Assessment Technologies and Coding/Marking Practices." National Academies of Sciences, Engineering, and Medicine. 2016. Assessing, Coding, and Marking of Highway Structures in Emergency Situations, Volume 1: Research Overview. Washington, DC: The National Academies Press. doi: 10.17226/24608.
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Suggested Citation:"Chapter 3 - Evaluation of Assessment Technologies and Coding/Marking Practices." National Academies of Sciences, Engineering, and Medicine. 2016. Assessing, Coding, and Marking of Highway Structures in Emergency Situations, Volume 1: Research Overview. Washington, DC: The National Academies Press. doi: 10.17226/24608.
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Suggested Citation:"Chapter 3 - Evaluation of Assessment Technologies and Coding/Marking Practices." National Academies of Sciences, Engineering, and Medicine. 2016. Assessing, Coding, and Marking of Highway Structures in Emergency Situations, Volume 1: Research Overview. Washington, DC: The National Academies Press. doi: 10.17226/24608.
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Suggested Citation:"Chapter 3 - Evaluation of Assessment Technologies and Coding/Marking Practices." National Academies of Sciences, Engineering, and Medicine. 2016. Assessing, Coding, and Marking of Highway Structures in Emergency Situations, Volume 1: Research Overview. Washington, DC: The National Academies Press. doi: 10.17226/24608.
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Suggested Citation:"Chapter 3 - Evaluation of Assessment Technologies and Coding/Marking Practices." National Academies of Sciences, Engineering, and Medicine. 2016. Assessing, Coding, and Marking of Highway Structures in Emergency Situations, Volume 1: Research Overview. Washington, DC: The National Academies Press. doi: 10.17226/24608.
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Suggested Citation:"Chapter 3 - Evaluation of Assessment Technologies and Coding/Marking Practices." National Academies of Sciences, Engineering, and Medicine. 2016. Assessing, Coding, and Marking of Highway Structures in Emergency Situations, Volume 1: Research Overview. Washington, DC: The National Academies Press. doi: 10.17226/24608.
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Suggested Citation:"Chapter 3 - Evaluation of Assessment Technologies and Coding/Marking Practices." National Academies of Sciences, Engineering, and Medicine. 2016. Assessing, Coding, and Marking of Highway Structures in Emergency Situations, Volume 1: Research Overview. Washington, DC: The National Academies Press. doi: 10.17226/24608.
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Suggested Citation:"Chapter 3 - Evaluation of Assessment Technologies and Coding/Marking Practices." National Academies of Sciences, Engineering, and Medicine. 2016. Assessing, Coding, and Marking of Highway Structures in Emergency Situations, Volume 1: Research Overview. Washington, DC: The National Academies Press. doi: 10.17226/24608.
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Suggested Citation:"Chapter 3 - Evaluation of Assessment Technologies and Coding/Marking Practices." National Academies of Sciences, Engineering, and Medicine. 2016. Assessing, Coding, and Marking of Highway Structures in Emergency Situations, Volume 1: Research Overview. Washington, DC: The National Academies Press. doi: 10.17226/24608.
×
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Suggested Citation:"Chapter 3 - Evaluation of Assessment Technologies and Coding/Marking Practices." National Academies of Sciences, Engineering, and Medicine. 2016. Assessing, Coding, and Marking of Highway Structures in Emergency Situations, Volume 1: Research Overview. Washington, DC: The National Academies Press. doi: 10.17226/24608.
×
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Suggested Citation:"Chapter 3 - Evaluation of Assessment Technologies and Coding/Marking Practices." National Academies of Sciences, Engineering, and Medicine. 2016. Assessing, Coding, and Marking of Highway Structures in Emergency Situations, Volume 1: Research Overview. Washington, DC: The National Academies Press. doi: 10.17226/24608.
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39 C H A P T E R 3 The objective of this chapter is to evaluate existing and emerging structural assessment prac- tices and technologies for use in emergency situations and recommend methodologies appropri- ate for development of an assessment procedure and coding and marking guidelines. This chapter is divided into the following sections: • Damage Characterization—This section summarizes the anticipated scale of damage to each structure type based on the hazard type and groups the various forms of damages reported in the literature into general types: structural, geotechnical, hydrological, and special case. • Applicability Categorization—Each approach and practice identified in the literature review was categorized based on its suitability for use in assessing, coding, and marking highway structure damage in emergency situations. High-level categorization of technology application consists of human-centric, generic, and specific techniques. The maturity level of the technologies was also considered. Finally, the applicability rating was also presented in context of damage extent, scale, and type. • Detailed Evaluation—Operational readiness as well as the technical data requirements of each technique was evaluated based on 13 categories: necessity for baseline data, frequency of updates, training requirements, measurement resolution, measurement accuracy, spatial coverage, opera- tion, technology availability, processing and analysis time required, technological maturity, level of automation, security, and speed. A scoring system ranging from 1 to 5 was used to rank each technique’s capabilities within each category. Explicit definitions are provided for each ranking to minimize subjectivity. In general, there are a lot of technologies available to aid in the assessment, coding, and marking process. Because of the various levels of sophistication, each technology has its own place within the context of a damage assessment timeline [Fast Reconnaissance (FR), Preliminary Damage Assessment (PDA), Detailed Damage Assessment (DDA), and Extended Investigation (EI)] as well as within an SHA’s current level of maturity or comfort with the technology. Hence, the focus on this chapter is to provide a solid understanding of each technology or process, and its potential applications, capabilities, and limitations, which will allow SHAs to select technologies that are appropriate for their organization. 3.1 Damage Characterization In this section, two-dimensional matrices of the expected damage to highway structures by emer- gency event and type of damage are presented. The main objective of these matrices is to provide a basis for the transportation agencies to establish emergency response priorities and to facilitate select- ing assessment methods that may need to be performed in case of different emergency situations. First, the anticipated damage to highway structure types by emergency events is categorized in Table 3-1 as either significant, moderate, minor, or unlikely. This categorization is based on the Evaluation of Assessment Technologies and Coding/Marking Practices

40 Assessing, Coding, and Marking of Highway Structures in Emergency Situations: Research Overview assumption that an emergency event has occurred that is significant enough to produce notice- able to significant consequences to at least one structure of interest. However, it is possible that a structure could experience a higher level of damage at extreme intensities of an emergency event or when subjected to prolonged exposure (i.e., the damage could jump one or two scale levels for specific combinations). Next, Table 3-2 groups the various forms of structural damages into four general types: struc- tural, geotechnical, hydraulic, and special case. These damage types were simplified from extensive literature review of the damage reports of previous emergency events. Structures Emergency Event Ea rth qu ak es Ts un am i To rn ad o an d H ig h W in ds H ur ric an e an d St or m S ur ge Fl oo di ng Sc ou r Fi re Bridges Tunnels Walls Culverts Embankments Overhead Signs Damage Scale Significant damage – Several collapses and irreparable damage to multiple structures across a large area. Moderate damage – Repairable damage to several structures. Minor damage – Localized damage to a few structures, most do not need significant repair. Damage unlikely. Table 3-1. Damage matrix in terms of emergency events and highway structures. Damage Type Damage Geotechnical Ground failure such as liquefaction, lateral spreading, landslides, etc. Slope instability Erosion Bearing capacity failure Active or passive failure Foundation settlement Structural Cracking and spalling of reinforced concrete members Flexural and shear failures of reinforced concrete or steel members Buckling, fracture, and tension failure of steel members Fatigue damage, including low-cycle fatigue Inelastic deformation and buckling Hydraulic Scour Debris impact Inundation leading to hydrostatic and hydraulic pressures Washout Special Cases Thermal expansion Reduction of strength and material properties due to thermal effects Efflorescence causing deterioration Decay of timber members Corrosion Table 3-2. Common forms of damage per type.

Evaluation of Assessment Technologies and Coding/Marking Practices 41 3.2 Applicability Categorization 3.2.1 Background This section categorizes technologies, approaches, and practices identified in the literature review according to their technical applicability toward assessing, coding, and marking struc- tures under emergency situations for potential damage identified in Table 3-1. The primary intent of this section is, from the perspective of technical applicability, to help agencies to select assessing techniques that match their backgrounds and current capabilities. Hence, the categori- zation is done from the user perspective, particularly to identify techniques that are most helpful for PDARs. For a detailed review of various sensing technologies and their use, the interested reader is referred to Ahlborn et al. (2010) and Vaghefi et al. (2012), which classify and rate technologies based on their capabilities for specific bridge elements and measurements of interests. Most of these advanced technologies would be more appropriate for later assessment stages (e.g., DDA and EI). The term “technique” used herein is a generalized notion, which includes all the assessing tech- nologies identified in the literature review; more importantly, it includes no- or low-technology manual assessing, coding, and marking techniques. In this section, these methods will be mostly categorized as “human-centric” techniques. For technological methods (that involve use of technological devices or equipment, or comput- ing methods), the maturity of the technology and the maturity of the organization (or institution) that will be using the technology should be clarified. To proceed with the technology applicability evaluation, the research team considered the three MCEER maturity categories—operational, developmental, and research—and systematically selected the technologies that are mostly in the maturity category of operational (Tralli 2000). 3.2.2 Technique Applicability Category The following categories of technique applicability are proposed: 1. Human-centric techniques. This category of techniques indicates that equipment or devices are not the dominant means in the practice; rather, a procedure is more emphasized that involves and is dominated by use of a human’s scientific and empirical knowledge in the field. The applicability of human-centric techniques is general or simply “general use.” 2. Generic techniques. This category is further divided into “generic simple” and “generic high- tech” techniques. The basic feature of this category is use of equipment or devices in the field, which generate data aiding or subject to a human’s further analysis and decision making. The term “generic” implies that the applicability of generic techniques is general or “general use.” 3. Specific techniques. Different specific situations will be defined in Subsection 3.2.2.3 for the tech- niques in this category. The applicability of specific techniques will be labeled as “specific use.” Each of these categories is described in more detail in the following subsections. 3.2.2.1 Human-centric Techniques Human inspection using the trained “naked-eye” plays a significant role in routine practice and emergency response; even though, as reviewed earlier, human inspection-only techniques are significantly limited to identification of visually observed distresses and anomalies. It is rec- ognized that almost all existing coding and marking practices are essentially a human-based in-situ operation. Therefore, human-based visual assessment, and existing coding and marking techniques, can be grouped and categorized as human-centric techniques.

42 Assessing, Coding, and Marking of Highway Structures in Emergency Situations: Research Overview 3.2.2.2 Generic Techniques There are many technological means, from simple to sophisticated ones, which can aid damage assessment. First, many of the assessment technologies in the literature review [e.g., digital cameras, smartphones/tablets, personal mobile computers, personal global position system (GPS) devices, and digital or paper-based GIS maps] are so simple to use and versatile that they can further facilitate human inspection in nearly all types of disaster events by identifying visible damage conditions. Second, a large number of sophisticated equipment/devices can be used in the field for performing advanced or accurate inspection in nearly all situations as well. Use of these techniques typically requires high-technology data interpretation and training prior to their use. These techniques may include optical or radio satellite platforms; airborne optical imaging platforms [including unmanned aerial vehicles (UAVs) / unmanned aerial sys- tems (UASs)]; airborne, terrestrial or water-borne geodetic sensing (e.g., lidar) equipment; and a few types of non-destructive sensing/imaging equipment. Therefore, the use of these tech- nologies can be grouped into two subcategories: generic simple techniques and generic high-tech techniques. 1. Generic simple techniques. The simple techniques include many consumer-grade global navi- gation satellite system (GNSS) devices, portable computers, and mobile imaging devices (e.g., photo cameras or smartphones), which have become ubiquitous and can be used to aid human- centric inspection, assessment, and coding techniques. Simple devices require no minimal training or expertise to operate. 2. Generic high-tech techniques. Techniques that need either expert-level training for operation or advanced processing packages for data interpretation are considered high tech. Several high- tech imaging or point-cloud generation devices are in this subcategory. They include (1) satel- lite or airborne imaging, which can be used for all types of regional-scale disasters; (2) advanced geodetic devices such as laser scanning/lidar, which can be used along with different platforms, for example, fixed-wing, helicopter, vehicle, static and hand-held; and (3) thermal imaging, ground penetrating radar (GPR), sonar, and other simple non-destructive techniques. High- tech devices require significant training and experience to operate. 3.2.2.3 Specific Techniques Many other equipment/device-based techniques are specific for applications in particular situations. Thus, from an applicability point of view, these technological techniques are catego- rized as specific techniques. These techniques may be used only for a certain type of emergency, structure damage type, or distress state or only when a certain condition is satisfied. Therefore, these techniques should be individually considered before use. For example, bathymetric devices are well suited to underwater scouring detection during flooding events. Although applicable to general structures, structural sensing devices for real- time monitoring, such as strain gauges and optical fibers, are mostly applicable to the monitor- ing of stress and strain field in structures; more importantly, practical deployment of structural sensing devices is only for critical transportation structures. The use of crowdsourcing or other citizen-scientist techniques involve special call-to-action for public involvement, which is a spe- cific condition to satisfy before using these technologies. In addition to the foregoing categorized techniques, agencies should consider many non-device/ equipment-based computing techniques (e.g., management software, databases/inventories, and emerging techniques such as crowdsourcing or smart apps). These databases, software, or comput- ing applications are either necessary for a certain specific hardware device when used in specific situ- ations or can facilitate the speed of analysis or communication. Therefore, they too are categorized as specific techniques.

Evaluation of Assessment Technologies and Coding/Marking Practices 43 3.2.2.4 Applicability Categorization Table Table 3-3 is a high-level categorization of these assessing, coding, and marking techniques based on their individual applicability. Two notes are given regarding this table: 1. Common features of using any high-tech equipment are the generation of large data sets and the burden of data processing, which often require specialized software and training. It follows that one of the primary limitations that prevents most transportation agencies from using generic or specific high-tech assessment technologies is the preparedness and training that is required to support the complex data processing efforts. Therefore, many digital data process- ing and information management software packages are developed and treated as necessary accessories for using high-tech devices. Therefore in Table 3-3, it is assumed that, for all high- tech techniques (generic or specific), software packages for data processing and interpretation are associated with the high-tech device or equipment. 2. “Limited general use” is used to describe two non-destructive evaluation techniques—infrared and ground penetrating imaging methods—that can be used to inspect damage associated with multiple structural materials. The reason for categorizing them as “generic techniques” is that portable and easy-to-use devices for the two technologies are available and can be implemented quickly for a relatively wide range of applications; however, their use is restricted by their inability to be operated in all environments because of their hand-held or portable features. 3.2.3 General Technical Applicability Evaluation Based on the applicability categorization scheme presented in Table 3-3, three additional high-level technical applicability evaluations are conducted in this subsection. The applicability evaluation is based on a straightforward decision-tree selection of assessing, coding, and mark- ing techniques. The decision tree (Figure 3-1) starts with a basic identification of the extent of damage. If the damage extends to only a single structure, the level of damage and the type of damage are then determined. Subsequently the applicable technique is selected. The simple deci- sion tree proposed in Figure 3-1 serves to evaluate technical applicability herein only. The actual technique selection process by transportation agencies relies on many other factors (which is further elaborated in Section 3.3). Based on this decision tree, the following subsections present the details of the high-level technical applicability evaluations. 3.2.3.1 Applicability in Terms of Damage Extent When technical applicability of techniques is being evaluated, two basic levels of damage extent—multiple/distributed structures and single object—are considered as follows: 1. Multiple/Distributed Structures a. Definition: Disaster induces damage to transportation structures at a large geospatial scale that extends to multiple transportation structures or a distributed network of transporta- tion structures (effectively the disaster extent may be at a community, city, state, and even a multi-state national scale). b. Applicable technique: Different remote sensing/GIS products are preferred (e.g., tech- niques 11, 12, 16, 19, and 20 in Table 3-3) and particularly crowdsourcing and modern mobile- and cloud-computing-based smart apps can be exploited (technique 34), if they are effectively deployed. 2. Single Structure a. Definition: All hazards may eventually damage individual structures, leading to local dam- age to different single structures. When selecting an assessing technique, two high-level identifications are necessary: the damage level and the damage type. b. Applicable techniques: Rely on the decision of the actual damage level and damage type.

44 Assessing, Coding, and Marking of Highway Structures in Emergency Situations: Research Overview Assessing, Coding, and Marking Short Description and Uses Applicability Maturity Category # Technique H um an -c en tr ic 1 Human damage inspection Naked-eye inspection of structural damage (e.g., collapse degree, crack/delamination types/degree and other surficial damage types). General use Operational 2 In-situ coding Manual coding using established protocols in the field. This is typically accomplished via a paper-based form completed by an inspector or a digital technology-based coding. General use Operational 3 In-situ marking Manual marking using established protocols in the field. This can include use of chalk, crayon, tapes of various colors, or digital codified patterns to communicate a structure’s status or identify locations of damage warranting extended investigation. General use Operational 4 Digital cameras Digital imaging of damage or recording of events; retagging may be available for some cameras (including special portable cameras, e.g., camera on a stick). General use Operational 5 Smartphones/tablets For field communication, photo capturing, and processing simple tasks as personal computers. General use Operational 6 Personal laptops/mobile computers For personal field data logging, reporting, and simple computing, and other simple computing tasks. General use Operational 7 Personal GPS/GNSS devices For personal positioning, navigation, or tracing paths. General use Operational 8 Cloth types/tape measures/Carpenter level/Calipers For local marking, and obtaining distance/width/thickness or other measurements. General use Operational 9 Compass/level Mechanical or simple digital direction/level finding devices. Used to determine tilts and rotations on structures. It also can be helpful in determining impact direction in the case of hazards such as tsunamis. General use Operational 10 Laser distance measures For quick and short-distance measurements, especially for hard to reach locations. General use Operational 11 GIS maps Digital or paper-based maps for field guidance, such as general maps, terrain maps, and other special-purpose maps, e.g., FEMA flood maps, municipal parcel maps. General use Operational 12 Satellite/airborne (optical or visually interpretable) images Optical or other satellite/airborne images that have been processed hence enabling simple visual interpretation of damage extents. General use Operational 13 Mobile (hand-held) three-dimensional imaging Emerging technologies that capture “depth” in scenes besides 2D imagery intensities. General use Developmental 14 Mobile imaging/video logging systems Mobile (e.g., vehicle-mounted) imaging for recording surface damage or video-based surveillance of many types of events. General use Operational 15 Inspection equipment Simple inspection equipment (sounding hammer, chain drags, ice picks, dye penetrant, range pole or probe, plumb bob, etc.). General use Operational G en er ic H ig h- Te ch 16 Mapping resource grade GPS Advanced, mapping-grade GPS for large-scale positioning, locating, or tracing features. General use Operational 17 Advanced laser range finder(Disto) Advanced, laser range finding for large-scale applications, enable more advanced calculations such as area and volume to be calculated in field. General use Operational 18 Simple airborne imaging (radio-controlled UAVs/UASs) Simple imaging using unmanned technologies using low-cost miniature UAVs with radio control. General use Developmental 19 Advanced airborne imaging tools (UAVs/UASs) Advanced imaging using unmanned technologies involving geo- referenced imaging systems. General use Under research 20 Lidar—all platforms (airborne, mobile, static terrestrial, underwater) Advanced point-cloud mapping of structural damage for most damage types. Static terrestrial and underwater systems are applicable for component/site analyses, mobile for highway-level analyses, and airborne for large-extent applications. General use Operational 21 Robotic total station These systems can be used to measure deformations, deflections at discrete locations on structures. General use Operational 22 Real-time kinematic GPS, permanently mounted GPS units Trace features, measure centimeter-level deformations on a structure. General use Operational 23 Thermal imaging (including analysis software) Non-destructive infrared imaging of different types of surficial damage/distresses; expert-level visual interpretation is necessary. Limited general use Operational 24 GPR (including analysis software) Non-destructive radio imaging of different types of shallow- surface damage/distresses; expert-level visual interpretation is necessary. Limited general use Operational G en er ic S im pl e Table 3-3. Technique categorization in terms of applicability.

Evaluation of Assessment Technologies and Coding/Marking Practices 45 Assessing, Coding, and Marking Short Description and Uses Applicability Maturity Category # Technique 27 Bathymetric vessel or robot-based survey Advanced point-cloud underwater survey for scour or other hydraulic damage detection. Specific use (underwater) Operational 28 Vehicle-mounted inspection system Advanced NDE systems featuring real-time (considering real traffic speed) sensing and processing. Specific use (traffic disturbance) Under research 29 Structural-monitoring sensors Structural health monitoring technologies based on vibration signals and software-based data processing is usually needed. Typically capable of real-time information. Specific use (technical and non- technical factors) Operational 29a Accelerometers Acceleration response for identifying structural modes or global damage condition. Specific use (detailed global) Operational 29b Strain gauges Local strain gauges for identifying local deformation or damage. Specific use (detailedlocal) Operational 29c Fiber-optics-based sensors Fiber-optics sensors or Bragg grating-based sensing that can be modulated for acceleration, strain, and temperature sensing. Specific use (detailed global and local response) Operational 29d Wireless sensor network Wireless (without use of conventional cable for data acquisition)based on different wireless communication protocols. Specific use (large- span critical structures) Developmental 30 Transportation structures inventory/databases (e.g., NBI) State-level or national transportation data infrastructure; usually used for geospatially large-extent investigation or research purpose. Specific use (when necessary and ready) Operational 31 Asset management software Used for digital editing or adding of structural damage/condition information based on latest acquired data. Specific use (when necessary and ready) Operational 32 Specific data analysis methods and software Image processing, machine learning methods for semi- or automatic interpretation. Specific use (when necessary and ready) Operational 33 Inspection management software (e.g., BIM) Used for in-field inspection and data management. Specific use (when necessary and ready) Operational 34 Emerging crowdsourcing, smart apps, and other citizen-scientist methods Used for public-involved disaster damage reporting or informing the public; modern mobile and cloud computing and communication infrastructure supports are necessary. Specific use (when public is called) Under research Sp ec ifi c 25 Simple mechanical devices Simple non-destructive or semi-destructive sampling devices for specific material strength evaluation (e.g., Schmidt hammer). Specific use (field material types) Operational 26 Other non-destructive methods Advanced non-destructive evaluation (NDE) methods for imaging and reconstruction of internal damage, such as x-ray, microwave Specific use (internal damage) Developmentalimaging. Table 3-3. (Continued). Assessing Method Selection Multiple or distributed Damage Extent Damage Level Single-Structure Remote sensing imagery/GIS products Damage Type Damage-level dependent methods Damage-type dependent methods Figure 3-1. Assessing, coding, and marking technique selection based on technical applicability.

46 Assessing, Coding, and Marking of Highway Structures in Emergency Situations: Research Overview 3.2.3.2 Applicability in Terms of Damage Level For a structure extent, the level of damage determines the applicability of each assessing, cod- ing, or marking method described in Table 3-3. The four damage levels are (1) undetermined damage, (2) intact to minor damage, (3) moderate damage, and (4) major damage to collapse of structure. The most applicable techniques for each of the four levels of damage are summarized in Table 3-4. 3.2.3.3 Applicability in Terms of Damage Type When the type of the damage can be simultaneously determined by human-centric techniques while deciding the damage level, the applicability of assessing, coding, and marking techniques depends on the types of damage. Table 3-5 identifies the techniques that are applicable to each damage type. For a detailed analysis based on specific indicators of interest, consult Ahlborn et al. (2010) and Vaghefi et al. (2012). 3.3 Detailed Evaluation of Techniques 3.3.1 Introduction This section will provide a detailed evaluation of each technique, both human inspection and assessment technology identified in Section 3.2. The intent of this evaluation is to aid in the decision-making process of when each technique would be suitable for use based on the emergency response timeline, magnitude of the event, availability of resources, skill set, and area impacted. A total of 13 categories were used to evaluate the operational readiness as well as the technical data requirements of each technique in light of the emergency timeline. A numerical scoring system, designed with the intent of removing as much of the subjectivity from the process as possible, was used to establish a relative ranking of each technique. 3.3.2 Methodology The approach begins by establishing the four critical stages of the emergency response timeline: • Pre-event preparation • Data collection/access • Data interpretation • Communication/reporting Damage Level Most Applicable Assessing, Coding, and Marking Techniques Undetermined damage Besides all possible generic techniques (4–24), all specific techniques (25–34) are needed for determining the type of damage. Intact to minor damage If damage is visible, human-centric techniques (1–3) and generic simple techniques (4–15) can be used. If damage is hidden, generic high-tech and specific techniques (16–34) can be used. Moderate damage Human-centric techniques (1–3) and generic simple techniques (4–15) are sufficient; some generic high-tech techniques (16–24) may be used as needed. Major damage to collapse Remote sensing (12) and human-centric techniques (1–3). Table 3-4. Applicability of techniques in terms of damage levels.

Evaluation of Assessment Technologies and Coding/Marking Practices 47 Thirteen categories (Table 3-6) were then established to specifically evaluate the way in which each technique supports the sub-tasks of these four primary workflows. A scoring system rang- ing from 1 to 5 was used to rank each technique with the desired or most beneficial condition within a category receiving the highest score and the least beneficial receiving the lowest score under normally expected conditions. For example, when evaluating the requirement for train- ing, a technique that involves a minimal level of training to complete a specific sub-task would receive a high score. 3.3.3 Assumptions Given the potentially broad interpretation that could be applied to a number of the categories when scoring the techniques, the following assumptions were made to focus the evaluation on the primary scope of this project and to provide a more narrowly defined, objective context: 1. The intent is for the technique to be evaluated based on its use to rapidly assess, code, and/or mark highway structures during emergency situations. Damage Type Damage Most Applicable Assessing, Coding, and Marking Techniques G eo te ch ni ca l Ground failure such as liquefaction, lateral spreading, landslides, etc. Slope instability Erosion Bearing capacity failure Active or passive failure Foundation settlement All human-centric and generic simple techniques will be applicable because of the visibility of the damage in most cases. For quantification, the generic high-tech technique, terrestrial lidar (20), is the most suitable for ground failure, slope instability, erosion, various capacity failure mechanisms, and foundation settlement. St ru ct ur al Cracking and spalling of reinforced concrete members Flexural and shear failures of reinforced concrete or steel members Buckling, fracture, and tension failure of steel members Fatigue damage, including low- cycle fatigue Inelastic deformation and buckling Subsurface cracking/void/ delamination damage of concrete; corrosion of steel rebars Interior (invisible) damage When damage is visible, all human-centric and generic simple techniques (1–15) and simple to complex strength devices (25) for material strength characterization. To enhance visibility, two generic high-tech techniques can be used: thermal imaging (23) for surface damage (e.g., cracking, spalling, flexure/shear/buckling/fatigue induced other damage patterns, etc.) and GPR imaging for other shallow subsurface damage; vehicle-mounted inspection system (28) for bridge deck. For interior damage, advanced non-destructive evaluation techniques (26). For all above structural damage, structural- monitoring solutions (29a–d) may be applicable for critical structures. H yd ra ul ic Scour Debris impact Inundation—leading to hydrostatic and hydraulic pressures Washout All human-centric and generic simple techniques (1–15). For volume (e.g., debris, inundation, and washout) characterization: terrestrial lidar (20). For bridge foundation scour, either manual scuba diving or the bathymetric survey (27). Sp ec ia l C as es Thermal expansion Reduction of strength and material properties due to thermal effects Efflorescence causing deterioration Decay of timber members Corrosion All human-centric and generic simple techniques (1–15). For strength characterization, simple to complex strength devices (25) for material strength characterization. Generic to specific NDE techniques (23, 24, 26). Table 3-5. Applicability of techniques in terms of damage types.

48 Assessing, Coding, and Marking of Highway Structures in Emergency Situations: Research Overview St ag e Category Score 1 2 3 4 5 Pr e- ev en t P re pa ra tio n Necessity for Baseline Data Continual in- situ measurements Multiple, periodic surveys required Detailed data set/survey required Basic data set required (e.g., drawings) No data necessary Frequency of Updates Real-time data, logged continually Monthly Annually Every several years Not required Training Extensive (years of experience) Significant (requires a course(s) months to years in length) Moderate (up to speed with a few short courses) Some (basic training in forms of short workshops and seminars) Little to none D at a C ol le ct io n/ A cc es s Measurement Resolution Several meters Meters Decimeters Centimeters Millimeters Measurement Accuracy Several meters Meters Decimeters Centimeters Millimeters Spatial Coverage Component/ element Structure/ site City/county Statewide Regional/ national Operation Duration Very slow (weeks) Slow (days) Moderate (hours) Fast (minutes) Very fast (seconds) Technology Availability Difficult to find/not available Requires specialist to collect and obtain Team can be mobilized or generally available consultant can be hired quickly to collect Readily available for commercial fee Readily available, free access D at a In te rp re ta tio n Processing and Analysis Time Required Very slow (weeks) Slow (days) Moderate (hours) Fast (minutes) Very fast (seconds) Technological Maturity Research Pilot projects Develop- mental Becoming standard of practice Operational Level of Automation Full human interaction, manual data collection Significant human interaction Semi- automatic— mix of human interaction and automated tools Automated, but results are available upon return to office Automated, results are available in situ C om m un ic at io n/ R ep or tin g Security Insecure Basic security in place Password protection Password protection and encryption Advanced security protocols combining hardware and software Speed Paper-based or uncommon medium (weeks to days) Hard-drive delivery (weeks) Flash- or hard- drive delivery (days) Internal data Internet server Table 3-6. Categories and corresponding score.

Evaluation of Assessment Technologies and Coding/Marking Practices 49 2. The primary scope of the investigation is based on an individual, single structure, unless otherwise indicated. The technique is being evaluated under the normally expected use conditions. In special cases, a system may be capable of higher performance than what is described in this evaluation. 3.3.4 Definitions of Categories Table 3-6 provides a brief description of how the scoring is defined for each category. The fol- lowing definitions are intended to provide additional insight into the scoring process: 1. Necessity for baseline data – Refers to the level of baseline data needed in order to effectively apply the technique. The range is from continuous to none. 2. Frequency of updates – Refers to the need for baseline data updates in order to effectively apply the technique. The range can be from real-time continuous to none. 3. Training – Refers to the need for training in order to make effective use of the technique. The range is from years of experience to none. 4. Measurement resolution – Refers to the spatial, temporal, and/or spectral resolution or density of measurements or observations that can be normally obtained with the technique for the entire structure. The range is from several meters to millimeters or, when applicable, frequency range from low to high. 5. Measurement accuracy – Refers to the absolute measurement accuracy of the technique. The range is from meters to millimeters. 6. Spatial coverage – This category is an exception to the proposed scoring system in that the extent goes beyond an individual structure to include larger geographic regions. The range is from an individual structural component up to the entire United States. 7. Operation duration – Refers to the amount of time required to obtain the desired result from the use of the technique. The range is from weeks to seconds. 8. Technology availability – Refers to the relative availability of the technique, considering the availability of equipment, software, and experts. The range is from difficult to find to readily available. 9. Processing and analysis time required – Refers to the requirement for processing the data obtained by using a specific technique. The range is from weeks to seconds (real time). 10. Technological maturity – Refers to the stage of maturity of the technique. The range is from the technique being in the research stage to fully operational (discussion of this is found in Section 3.2). 11. Level of automation – Refers to how automated the process is for obtaining a result. The range is from completely manual to fully automated. 12. Communication security – Refers to the level of security associated with the transmission of data via manual recording, digital storage, or digital communication network (e.g., Internet, 3G/4G network). The range is from no security to the highest level. 13. Communication speed – Refers to the speed of digital data transfer. The range is from days/ weeks to the speed delivered by a high-speed digital network. 3.3.5 Evaluation Table 3-7 provides the scoring for each technique as evaluated within each category. These scores are an important relative indicator of the potential value of each technique in the assess- ing, coding, and marking of structures in emergency situations.

Assessing, Coding, and Marking Techniques Pre-event Preparation Data Collection/Access Data Interpretation Communication/ Reporting Necessity for Baseline Data Frequency of Updates Training Measurement Resolution Measurement Accuracy Spatial Coverage Opera- tion Duration Technology Availability Processing and Analysis Time Required Technological Maturity Level of Automation Security Speed H u m a n - c e n t r i c Human damage inspection 5 5 1 to 4 4 5 2 3 2 to 3 4 5 5 2 n/a In-situ coding 5 n/a 1 to 4 n/a n/a 2 5 3 5 5 5 4 n/a In-situ marking 5 n/a 3 to 4 n/a n/a 2 5 3 5 5 5 4 n/a G e n e r i c S i m p l e Digital cameras 5 5 5 2 3 2 5 5 5 5 5 4 5 Smartphones /smart tablets 4 5 5 2 2 2 5 5 5 4 5 4 5 Personal laptops/mobile computers 3 5 4 2 2 2 5 5 5 5 5 3 5 Personal GNSS devices 5 5 4 2 2 3 5 5 4 5 5 4 4 Cloth types/tape measures/ carpenter level/calipers 5 5 5 1 4 to 5 1 4 5 4 5 5 5 5 Compass/level 5 5 4 1 4 1 to 2 4 4 4 5 5 5 5 Laser distance measurement devices 5 5 3 1 5 2 4 4 4 5 5 5 5 GIS maps 3 3 to 4 3 1 to 2 2 to 3 5 5 4 4 5 5 5 4 Satellite/airborne (optical or visually interpretable) images 3 3 to 4 3 3 1 5 2 3 2 5 5 5 4 Mobile (hand-held) three- dimensional imaging 5 5 3 4 4 2 4 3 3 3 4 5 3 Mobile imaging/video logging systems 5 5 4 3 2 5 3 3 2 5 3 5 3 Inspection equipment 5 5 5 3 3 1 4 5 4 5 4 to 5 1 1 G e n e r i c H i g h - T e c h Mapping resource grade GNSS 5 5 3 2 3 2 4 4 4 5 3 5 4 Advanced laser range finder (Disto) 5 5 3 1 5 2 5 4 5 5 5 5 5 Simple airborne imaging (radio-controlled UAVs/UASs) 5 5 2 4 3 2 4 2 3 2 3 4 4 Advanced airborne imaging tools (UAVs/UASs) 5 5 1 5 4 3 4 2 3 2 3 4 4 Table 3-7. Evaluation of assessing, coding, and marking techniques for use in emergency situations.

Ge n e r i c H i g h - T e c h Lidar—all platforms (airborne, mobile, static terrestrial, underwater) 5 5 1 5 4 to 5 2 to 5 3 to 4 3 3 4 3 5 3 Robotic total station 5 5 2 1 5 2 3 4 4 5 5 5 5 Real-time kinematic GPS, permanently mounted GPS units 1 1 2 1 4 to 5 2 3 to 5 4 2 5 3 4 4 Thermal imaging (including analysis software) 5 5 1 3 3 1 to 2 3 2 2 5 3 5 3 GPR (including analysis software) 5 5 1 3 3 2 3 2 2 5 3 5 3 S p e c i f i c Simple mechanical devices 5 5 5 1 4 1 5 4 4 5 5 5 5 Other non-destructive methods 5 5 3 1 4 1 5 3 4 5 5 5 5 Bathymetric vessel or robot- based survey 5 5 1 3 2 to 3 2 3 3 2 5 3 5 3 Vehicle-mounted inspection system 5 5 2 3 4 3 3 3 2 4 3 5 3 Structural-monitoring sensors a. Accelerometers 1 1 2 1 5 2 3 3 3 5 3 5 4 b. Strain gauges 1 1 2 1 5 2 3 3 3 5 3 5 4 c. Fiber-optics-based sensors 1 1 2 1 5 2 3 3 3 5 3 5 4 d. Wireless sensor network 1 1 2 1 5 2 3 3 5 3 3 3 5 Transportation structures inventory/databases (e.g., NBI) 2 3 2 1 4 4 to 5 4 3 4 5 5 4 4 Asset management software 3 3 3 1 2 5 4 4 4 4 5 4 4 Specific data analysis methods and software 2 2 3 1 2 5 4 3 2 4 4 4 4 Inspection management software 2 3 3 1 2 2 4 3 4 5 5 4 4 Emerging crowdsourcing, smart apps, and other citizen-scientist methods 4 3 4 1 1 5 4 5 4 4 5 1 4 n/a = not applicable

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TRB’s National Cooperative Highway Research Program (NCHRP) Research Report 833: Assessing, Coding, and Marking of Highway Structures in Emergency Situations, Volume 1: Research Overview provides background information and an overview of the process, supporting manuals, and training materials used to help agencies assess highway structures in emergency situations.

NCHRP Research Report 833, Volume 1, Volume 2, and Volume 3; along with NCHRP Web-Only Document 223: Guidelines for Development of Smart Apps for Assessing, Coding, and Marking Highway Structures in Emergency Situations provides guidelines for related coding and marking that can be recognized by highway agencies and other organizations that respond to emergencies resulting from natural or man-made disasters.

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