BACKGROUND

Advances in technology have introduced equipment and tools to facilitate three-dimensional (3D) engineered models for construction, including the use of automated machine guidance (AMG) for grading and excavating; fine grading and base preparation; and concrete paving. Contractors traditionally use the contract plan sets to create their own 3D models, but a trend to deliver digital data as a supplement to the plan sets is emerging. Incorporating 3D model-based design has enabled project teams to communicate design intent to downstream users more effectively, and offers opportunities to improve overall efficiency of the highway infrastructure project delivery process. However, changing the medium of construction contract information also creates a procedural challenge for field inspections.

To replace two-dimensional (2D) plan sheets with 3D models could make it challenging for inspectors to accomplish field verification of contract requirements, which requires user-friendly tools specifically designed for construction inspection tasks to review contract requirements in a new, digital medium. Therefore, research is needed to aid state departments of transportation (DOTs) to evaluate the technical requirements for the selection of 3D model viewers to be implemented for model-based construction inspection.

OBJECTIVE

The objective of this research is to develop a guide for state DOTs to evaluate the technical requirements for the selection of 3D model viewers for construction inspection.

RESEARCH PLAN

The research plan should (1) include a kick-off teleconference with the research team and NCHRP convened within 1 month of the contract’s execution; (2) address how the proposer intends to satisfy the project objective; (3) be divided logically into detailed tasks necessary to fulfill the research objective and include appropriate milestones and interim deliverables; and (4) incorporate opportunities for the project panel to review, comment on, and approve milestone deliverables.

Accomplishment of the project objective will require at least the following tasks.

TASKS

Phase I — Planning

Task 1. Conduct a literature review of relevant research and current state-of-practice related to 3D model viewers for construction inspection. The review shall include published and unpublished research conducted through the NCHRP; Federal Highway Administration (FHWA); and other national, international, state, and pooled-fund sponsored research.

Task 2. Conduct a survey of DOTs to identify 3D model viewers currently used for construction inspection. Collect data needed to achieve the research objective with consideration of the maturity of applications of 3D model viewers.

Task 3. Synthesize the results of Tasks 1 and 2 to identify the knowledge gaps for evaluating and selecting 3D model viewers for construction inspection. These gaps should be addressed in this research or in the recommended future research as budget permits.

Task 4. Propose a methodology to achieve the research objective to be fully developed in Phase II. At a minimum, the methodology shall address the following:  

• Identify the construction inspection activities that can utilize 3D model viewers;
• Define a list of disciplines that can utilize 3D model viewers (e.g., utilities, drainage, structures, etc.) and the elements that are typically included in a 3D model;
• Define a glossary of standard terminologies and applications used with 3D model viewers;
• Identify 3D model viewer technology to support construction inspection using 3D engineered models. This should include, but not be limited to, the functionality of software/hardware and technology, the ability to provide simple interface via mobile applications, the capability to connect with construction administration systems, and the capacity to function without Internet or Wi-Fi connection;
• Identify the data exchange standards and requirements (e.g., industry foundation classes (IFC)) to ensure compatibility and continuous flow of data from inception to asset management, including the creation or development of digital as-built drawings;
• Identify the advantages and disadvantages using 3D model viewers for construction inspection activities and elements;
• Identify any desired features and capabilities not currently provided by existing 3D model viewers;
• Develop a criteria-based assessment to assist construction inspectors, to include, but not be limited to, hardware requirements, offline capabilities, user capability functions, and data input/output format compatibility; and
• Develop resources that identify potential implementation requirements, procedures (including quality control (QC) and quality assurance (QA)), strategies, training needs, and challenges as it relates to 3D model viewers.

Task 5. Propose a preliminary outline for the guide based on the proposed methodology.

Task 6. Prepare Interim Report No. 1 that documents Tasks 1 through 5 and provides an updated work plan for the remainder of the research. This report should include a presentation to demonstrate examples of the capabilities of 3D model viewers with corresponding inspection activities assessed from Task 4. This report must be submitted to NCHRP no later than 6 months after contract execution. The updated work plan must describe the process and rationale for the work proposed for Phases II though IV. 

Note: Following a 1-month review of Interim Report No. 1 by the NCHRP, the research team will be required to meet in-person with the NCHRP project panel to discuss the interim report. Whether in-person in Washington, D.C. or online, NCHRP will host the meeting and be responsible for any panel member costs to attend the meeting. Work on Phases II through IV of the project will not begin until authorized by the NCHRP.

PHASE II — Methodology Development

Task 7. Develop the methodology according to the approved Interim Report No.1.

Task 8. Develop examples to demonstrate the developed methodology. The selection of the examples should include at a minimum the identified 3D model viewer technologies in Phase I and should include at a minimum 4 to 6 representative case studies of state DOT construction projects on different infrastructure types that showcase:

• Successful integration of 3D model viewers for construction inspection;
• Varying expertise levels of 3D model viewer product delivery; and
• Utilization with cross-agency disciplines to include, but not limited to, maintenance, utilities, bridge, and right-of-way.

Task 9. Provide a detailed description of every chapter and section of the proposed guide and complete a sample chapter that is publication-ready of the proposed guide. The guide should include a proposed implementation plan for state DOTs to integrate 3D model viewers for construction inspection.

Task 10. Prepare Interim Report No. 2 that documents the results of Tasks 7 through 9 and provides an updated work plan for the remainder of the project. This report is due no later than 8 months after approval of Phase II. The updated plan must describe the work proposed for Phases III and IV. 

Note: Following a 1-month review of Interim Report No. 2 by the NCHRP, the research team will be required to meet in-person with the NCHRP project panel to discuss the interim report. Whether in-person in Washington, D.C. or online, NCHRP will host the meeting and be responsible for any panel member costs to attend the meeting. Work on Phases III and IV of the project will not begin until authorized by the NCHRP.

PHASE III — Guide Development

Task 11. Develop the guide according to the approved Interim Report No. 2.

Task 12. After NCHRP approval of the draft guide, plan and conduct a workshop with 20 representatives of DOTs and other stakeholders to review the draft guide and implementation plan. Revise the draft guide according to the outcomes of the workshop. The invited representatives shall be approved by NCHRP.

Task 13. Prepare Interim Report No. 3 that documents the results of Tasks 11 and 12 no later than 8 months after approval of Phase III. The updated work plan must describe the work proposed for Phase IV.

PHASE IV — Final Products

Task 14. Revise the draft guide and workshop materials considering the NCHRP’s review comments.

Task 15. Prepare a final deliverable that documents the entire research effort. Final deliverables should include, at a minimum (1) a research report documenting the work performed and used to develop the guide, (2) the guide as a stand-alone document, (3) presentation material, and (4) technical memorandum on implementation. 

STATUS: Research in progress.