North Mountain Geohazards SOQ

North Mountain

Geohazards

STATEMENT OF QUALIFICATIONS

250+ US OFFICES

130 YEARS IN BUSINESS

15k+ US EMPLOYEES

BY THE NUMBERS

2

North Mountain Geohazards

Geohazard Overview | SOQ

GEOHAZARD OVERVIEW

Geological hazards pose significant safety and eco nomic challenges, particularly in rural, mountainous regions of the United States. Our geohazards consult ing team specializes in comprehensive services, includ ing geohazard risk assessment, geotechnical investi gations, debris flow, landslide, and rockfall mitigation design, and emergency response. With extensive experience across the Mountain West and Southwest, we collaborate with WSP transportation specialists to provide comprehensive solutions to geohazards problems. Our proven track record with state trans portation departments underscores our commitment to reducing geohazard impacts through effective, Future-Ready solutions. We prioritize safety, reliability, and minimal maintenance, ensuring long-term protec tion and enhanced community resilience. Geohazards Investigation Many clients know they have geohazard issues at a site or in an area or corridor, but what do you do about it? How bad is it? Which sites do you mitigate and in what order, and how much should you budget for? These are questions that WSP excels at providing answers to. It begins with a geohazards investigation where an inventory of the geohazard sites is prepared, and field assessments are conducted. We have experience with qualitative ranking systems, as well as quantitative risk assessment where detailed calculations are made for likelihood and consequence of a geohazard event. A conceptual mitigation design is prepared quickly for many of the worst sites based on WSP’s extensive ex perience with mitigation design. With the quantitative risk assessment and high-level cost estimates, a bene fit-cost study can be performed, helping owners make decisions on if and where to mitigate, and how much money to budget.

Question today Imagine tomorrow Create for the future.

3

Geohazard Risk Management Process

1

Inventory

2

Initial Qualitative Screening

A desktop study to collect available geohazard data and prepare a database of geohazard sites.

3

Field Investigation

Perform an initial, expert-based qualitative ranking of the site. Note sites that are not significant or are already mitigated to make the number of sites in subsequent steps more manageable.

4

Inter

Visit sites in the field and collect observations, measurements, notes, photos, and 3D drone models (where necessary).

Interview maintenance personnel and other people with institutional knowledge of the geohazard sites.

4

North Mountain Geohazards

Geohazard Overview | SOQ

rviews

5

Update Qualitative Analysis

6

Quantitative Risk Assessment

Use field data and interviews to finalize the qualitative analysis and site ranking. Agree with owner how many sites advance to subsequent stages.

7

Conceptual Mitigation

Assess likelihood of geohazard events in terms of annual probability of occurrence. Assess consequence in terms of dollars if an event occurs. Compute annual risk (in $$) of a geohazard event for each site.

8

Benefit-Cost and Project Planning

Prepare simple conceptual/high level mitigation designs and cost estimates based on the experience of subject matter experts.

9

Mitigation Design and Construction

Perform a benefit-cost analysis for site mitigation and collaborate with the owner

10

Monitor

Perform final design of mitigation, including additional, more detailed site assessments, and preparation of contract documents. Provide support during the construction phase.

to develop mitigation projects to advance to

Install monitoring where warranted. Continue periodic site visits to watch for increases in likelihood or consequence that warrant sites being reconsidered for mitigation.

planning stage and ultimately design and construction.

5

GEOHAZARD SERVICES

Geotechnical Investigation WSP staff employ a range of investigation techniques to evaluate conditions that pose geotechnical risks for an existing structure, planned development, or mitigation project. As part of our assessment, we look at soil and rock properties, geology and geomorphology, the distribution of faults and fractures in rock, and the groundwater regime below the area of interest. We do this to understand how they interact with proposed construction or instability issues. We are familiar with all methods of subsurface investigations, including various types of drilling and sampling, CPT testing and geophysics. We have local or regional labs available to service most projects and have expertise in advanced geotechnical testing that small geotechnical firms cannot offer. Debris Flow Mitigation Design Our team excels in emergency planning, debris flow modeling, mitigation design, and post fire debris flow assessments. Our expertise in modeling, risk assessment, and mitigation design, combined with our practical experience in emergency response and infrastructure protection, positions us as a leader in the field. The teams experience ranges from designing mitigation for individual basins to large-scale corridor studies and risk assessments. By focusing on quick deployment, field adaptability, and constructability and maintenance, we provide innovative and effective solutions to manage and mitigate debris flow risks, improving the safety and resilience of critical infrastructure and communities.

WSP’s team has more than 30 combined years of providing emergency response to clients.

BY THE NUMBERS ENGINEERING NEWS-RECORD 2024 RANKINGS

#4 #5 #6

TOP 20 DESIGN FIRMS FOR TRANSPORTATION

TOP 500 DESIGN FIRM

TOP 200 ENVIRONMENTAL FIRM

6

North Mountain Geohazards

Geohazard Services | SOQ

Landslide Mitigation Design Whether they are deep-seated or surficial, landslides are disruptive to assets and can be deadly under the right circumstances. Having a team that understands both the geological setting and the geotechnical engineering mechanism of failure is critical to success. WSP has a deep bench of geo-experts with these skill sets. We have been involved in major landslide studies, and have designed mitigation consisting of tieback anchors, lightweight fill, soil mixing columns and shear walls, soil nails, and earth buttresses, etc. There is no one-size-fits-all solution – it requires sound engineering judgement and creativity while factoring in constructability and cost. Rockfall Mitigation Design Typical rockfall hazards include unstable, deteriorating soil and rock cuts, naturally occurring detachment of large blocks from the outcroppings above the road, and remobilization of rock blocks that have been deposited in the slopes, then exposed in the over-steepened, upper soil parts of cut slopes. Our team has extensive experience in rockfall mitigation, demonstrated through numerous successful projects across various challenging terrains. Our team has addressed rockfall hazards to protect critical infrastructure through methods such as trim blasting, mechanical rock excavation, ditch improvements, scaling, installation of lightweight and heavyweight draped mesh and pinned mesh, rockfall fences, rock bolting, and shotcrete buttressing.

Emergency Response Rapid geohazard events usually result in road closures, either to remove debris or out of caution that the event may not be finished and may pose a threat to the traveling public. Immediate response on natures schedule, and accurate evaluation and management of these events is critical for public safety and mobility as well as the safety of maintenance staff and other responders to the scene. Effective incident management from the time the road closes to completion of subsequent activities is key to minimizing corridor performance impacts and promoting a positive image to the public. Personnel responding to events will be qualified to evaluate the source and surrounding area to determine whether scaling or other measures are required for the safety of staff and users. Responders will be trained in rope access and capable of accessing these sites. The use of unmanned aerial vehicles (UAV) for quick observation of source areas, trajectories and potential access routes has become routine whenever possible. Use of a UAV and rapid, in-house data processing will provide greater efficiency and safety and documentation of areas that can be shared digitally with staff during emergencies. WSP will provide our opinion of urgency and follow up with recommendations and designs for future actions including scaling, temporary barriers, permanent barriers, instrumentation, or other stabilization or protective measures. As stated above, we provide construction layout, inspection and engineering assistance to facilitate successful completion and documentation of the project.

7

Foundation Systems Our geotechnical engineering teams have extensive experience designing structural foundations, allowing us to design practical solutions for new development as well as remediation projects. Whether we are dealing with buildings, bridges, roadways, retaining walls, or other infrastructure, our professionals are well suited to gather the information necessary to make appropriate foundation design decisions. Our geotechnical staff has experience delivering economical and dependable foundation systems at sites with challenging subsurface conditions. We have provided analysis, design recommendations, and construction quality control for the following: z Auger-cast piles z Drilled shafts z Driven piles z Shallow foundations z Micropiles z Mats/Slab-on-grade In addition, we have extensive experience in the remediation of structural foundations like compaction grouting, chemical grouting and underpinning.

8

North Mountain Geohazards

Geohazard Services | SOQ

Earth Retaining Structures WSP geotechnical engineers have experience in both the design of new earth retaining structures and the remediation of existing ones. We are experienced with the design of both temporary and permanent wall systems such as sheetpiles, soldier piles, tie back walls, soil nail walls, MSE walls, and cast-in-place concrete retaining walls. We are especially skilled at the selection and design of walls on steep slopes. The design of the most effective wall system is highly dependent on factors including the wall height, aesthetic requirements, foundation soil conditions, water table location, soil corrosivity, and backfill materials. We are accustomed to tailoring our site investigation to provide a thorough understanding of the site conditions important in determining the most effective earth retaining structure to meet the needs of our clients.

Data Collection and Management

Data management is critical for the long term management of geohazards, to properly inventory potential hazards and track them through time (including changing conditions or hazards, assessments and/or remediation that may be completed, etc.). We have experience with designing, implementing, and maintaining data management systems ranging from management of individual site data to overall geohazard management programs. Data management typically involves management of both spatial (e.g., GIS) and non-spatial (e.g., time-series data, photographs, reports, actions items, etc.) data. WSP typically aims to utilize non-proprietary software packages that can be customized to fit project or client objectives and can ultimately be managed and maintained directly by our clients if they desire. The systems can also be expanded to include automated workflows, event detection, weather forecasting for decision-making, real time alerts, proactive and predictive analysis, visualization and reporting, and more.

9

RELEVANT PROJECT EXPERIENCE

NMDOT District 5 (D5) Rockfall Study, Northwest, New Mexico WSP is conducting a rockfall study which includes office and field work to characterize rock fall hazards along 12 highway corridors in northwest New Mex ico. Our team inventoried nearly 200 rockfall sites and rated the hazard with a three-tier ranking system. High-level conceptual cost estimates were developed for 79 of the highest hazard sites. Wilson provided an environmen tal screening of the sites to aid in the assessment of mitigation op tions and provided drone flights of selected sites for generating 3D models. WSP developed a custom database to manage the data using ArcGIS Online and SharePoint. The management and use of this data is a true geotechnical asset management problem and will be used by NMDOT D5 for planning purpos es to prioritize fixing these cor ridors to improve safety, reduce maintenance costs and maintain mobility. WSP met the schedule and budget on this project.

State Highway (SH) 133 Corridor Study and Mitigation Design, Colorado The Colorado SH 133 Corridor is severely impacted by rock fall, debris flows, landslides, avalanches, and the occasional sinkhole. WSP conducted a cor ridor study that involved inven torying 300 geohazard sites and performing quantitative risk assessment on 125 of them. Conceptual mitigation options with preliminary cost estimates were prepared for 50 of the highest risk sites, allowing for benefit-cost ratios to be comput ed. Based on the findings, five mitigation projects were un dertaken, primarily designed by WSP, representing New Mexico Department of Transportation (NMDOT) sites that have been mitigated, are under construc tion, or are under design. When these projects are completed, they will ultimately result in an approximate $18.5 million reduc tion in risk exposure compared to $16.8 million in construction costs. WSP met the schedule and budget on this project.

Interstate 70 Glenwood Canyon Debris Flow Mitigation, Garfield County, Colorado

During the Grizzly Creek fire in 2020 that burned through Glenwood Canyon, significant storms in the summer of 2021 caused major debris flows that caused damage to Interstate 70, closed the freeway for weeks, and exposed additional risks to highway infrastructure. WSP evaluated the debris flow hazard to viaduct piers and spans and provided preliminary mitigation designs. The team designed debris flow fences and micropile pier protection structures as well as gabion walls to protect road way infrastructure. WSP coordi nated plans and specifications packages for this emergency project and provided trouble shooting and support to CDOT during the construction phase.

Client: Colorado Department of Transportation (CDOT)

Client: Minnesota Department of Transportation (NMDOT)

Client: Colorado Department of Transportation (CDOT)

10

North Mountain Geohazards

Relevant Project Experience | SOQ

Highway 40, Colorado

I-25 La Bajada Hill Settlement and Slope Stability WSP was the geotechnical de signer for the I-25 embankment mitigation project between Albuquerque and Santa Fe. The embankment was widened in the early 1980s with high shale content fill, which has subse quently deteriorated and re sulted in excessive pavement settlement and marginal slope stability. Mitigation efforts in cluded comparative cost analysis of mechanically stabilized earth buttressing, soil nail/ground anchor stabilization, and ground improvement. The ground improvement option was selected since it addressed both settlement and slope sta bility. The ground improvement design consisted of soil mix columns supporting a geog rid load transfer platform that bridges the underlying columns and supports a reconstructed pavement structural section. A performance-based design was presented with flexibility for the column diameter and spacing. The contractor selected 10-foot diameter columns, and over 960 soil mix columns were installed, comprising over 300,000 CY of soil cement. The project was successfully completed in 2024.

State Road 39, Ogden Canyon Phase 1 and 2 Transportation Use Study, Utah Phase 1 of the Ogden Canyon Transportation Use Study includ ed a literature search and a brief field trip to provide a high-lev el evaluation of the type and severity of geological hazards that could affect future trans portation improvements within the canyon, as well as east of the canyon along both sides of Pineview Reservoir. Phase 2 of the study provided a more detailed feasibility level invento ry and prioritization of rockfall hazards.

WSP worked directly with CDOT to identify high priority areas for scaling efforts. The project was a two-mile stretch through Byers Canyon along Highway 40. Over a two-week period, the WSP geohazards team directed two scaling crews on which rocks to knock off the rock face based on fractures, surrounding geologic structures, and rock orientation in the slope. Both scale bars and airbags were used to address a variety of different sized rocks. WSP staff also utilized their rope access training to assess the slope from all angles. This work helped reduce the amount of rock that was falling into the road, causing travel hazards throughout the canyon.

Client: Minnesota Department of Transportation (NMDOT)

Client: Colorado Department of Transportation (CDOT)

Client: Utah Department of Transportation (UDOT)

11