Slope Stability Geostudio
Robyn Ruder
GeoStudio 2D offers a range of numerical analysis tools for simulating conditions at and below the ground surface. From natural soil and rock slopes, to dewatering systems or tailings storage facilities, you can use GeoStudio 2D to model the conditions you need for better insights into your geotechnical projects.
SLOPE/W is the leading limit equilibrium slope stability software for soil and rock slopes, analysing both simple and complex problems for a variety of slip surface shapes, pore water pressure conditions, soil properties, and loading conditions.
GeoStudio 2D Advanced has the capabilities of the GeoStudio 2D, as well as the ability simulate steady-state and transient groundwater flow in both saturated and unsaturated soil and rock. GeoStudio 2D Advanced can be used to analyse geotechnical engineering challenges such as rapid drawdown analysis, complex seepage analyses and much more.
SEEP/W is a powerful finite element software product for modelling groundwater flow in porous media. SEEP/W can model simple saturated steady-state problems or sophisticated saturated/unsaturated transient analyses with atmospheric coupling at the ground surface.
GeoStudio 2D Ultimate expands the capability of GeoStudio 2D Advanced with functionality to analyse static and dynamic stress and deformation within soil or rock including coupled consolidation, finite element stress stability, and the ability to use finite element results in the limit equilibrium analysis.
QUAKE/W is a powerful finite element software product for modelling earthquake liquefaction and dynamic loading. QUAKE/W determines the motion and excess pore water pressures that arise due to earthquake shaking, blasts, or sudden impact loads.
GeoStudio 2D offers a range of numerical analysis tools for simulating conditions above and below the ground surface. GeoStudio 2D can be used for a range of applications including natural soil and rock slopes, regional groundwater systems, excavations and open pit mines, dewatering systems, earthen dams and levees, reinforced earth structures, and tailings storage facilities.
Learning content for all GeoStudio products, including courses, example files and product manuals, is available in the Seequent Learning Portal (a free Seequent ID is required to view this content). Additional content like past webinars, how-to guides, industry insights, and new feature information are found on the GeoStudio Blog. Technical support is including when purchasing a license. Find answers to common questions or submit a support ticket in the GeoStudio Support Portal.
GeoStudio 2D (SLOPE/W) offers the foundational capability to perform Limit Equilibrium slope stability analysis for soil and rock. GeoStudio 2D offers a comprehensive list of features, including:
We have bundled a 12-month license for trusted Bentley software with customizable training from experts and call it our Virtuoso Subscription. With lower upfront costs and flexible support options, businesses of all sizes can now compete with the industry's heavy hitters.
The vision of Seequent, the Bentley Subsurface Company, is to provide a series of subsurface solutions that seamlessly integrate into each stage of infrastructure development. The workflow begins with field data collection and management with OpenGround, moves on to subsurface characterization and geological modeling with LeapFrog Works, and culminates in the advanced stage of geotechnical analysis with PLAXIS and GeoStudio.
Geotechnical analysis is a fundamental step in the development of many infrastructure projects. This step is supported by numerical analysis, where changes in stress and deformation in existing and planned structures are examined. Establishing a comprehensive terrain model with accurate design parameters prior to analysis is crucial to reflect expected terrain conditions. The insights gained from this analysis guide the selection, design, and specification of solutions.
GeoStudio has been widely used for geotechnical analysis for well over 30 years. It has several unique features that make it a stronger, more reliable, long-term solution for geotechnical analysis than PLAXIS LE, and it interoperates with a wide range of cloud-based applications.
GeoStudio offers superior functionality and interoperability with other Seequent products, such as Leapfrog, PLAXIS (FEM), and other cloud-based applications. These features make GeoStudio an excellent option for the increasing number of users who are building more connected workflows and embarking on their digital twin journeys.
GeoStudio has a long track record in limit equilibrium slope stability analysis for civil and mining engineering projects, which has made it a robust and trusted solution for a range of slope stability, groundwater flow, and environmental challenges.
A detailed stability analysis of the Ripley landslide in central British Columbia, Canada, was originally performed in PLAXIS LE as part of a graduate research project. This model assessed limit equilibrium stability analysis and investigated the influence of changing pore water pressure conditions at this site. GeoStudio was used to verify the results and observed a failure mechanism in the Ripley landslide. Integral features used in GeoStudio for this analysis were:
GeoStudio can save up to 70% to 80% of design time and provide a deeper understanding of your project. In a slope stability problem, you can create a quick model, simultaneously perform a straightforward slope stability and sensitivity analysis, and access powerful visualization features to interpret model results.
Because this is a project that does not have some sort of prototyping product, a less iterative process was used. The design was started at a high level and gradually moved into more detailed design throughout the course. Initially the team looked into three renewable methods: photovoltaic (PV), wind, and hydro. After evaluation of the environmental factors of the site, such as geographic factors, solar irradiation, and weather patterns, it was determined that photovoltaic electric generation was the most cost effective method.
Before other work could start, the solar panel was chosen. This was done using a python script that ranked and sorted 55 different solar panels by price, power output per area, and efficiency. Weather data including wind speeds and solar irradiance was analyzed based on data provided by a weather station at Cripple Creek and Victor Mine. When the chosen slope for panels changed, all the same calculations were used to calculate power output and panel quantity.
Once the solar plant was determined feasible, detailed civil work began, including a stope stability analysis. Three direct shear tests were also done on a soil sample from the slope to input into GeoStudio. GeoStudio determined:
The team then used The System Advisor Model (SAM) software, created by the National Renewable Energy Laboratories, to simulate the proposed generation site. This software was used to accurately calculate monthly power generation from our area based on solar panel choice, weather data, and slope orientation (S-E). Below in Figure 2 is a screenshot of the software in use.
Economics
For economic analysis, the SAM software was primarily used. SAM considered chosen equipment, power output, current tax credits, the price of power that Newmont pays, and other variables to output NPV, detailed cash flows and other economic models. The SAM software was also used to prove that battery storage is not worth the capital cost.
Under the guidance of technical advisors and Mike Aires, a design for a solar array was developed using typical industry engineering calculations and analysis. The design is a simple, efficient system that will provide the following:
With the help of our professors, we were able to run soil tests and analyse the slope stability in GeoStudio. This concluded that the hillside would not need benches for stability. Without benches, there is more area available for solar panels and therefore more power.
The three direct shear tests and GeoStudio helped to generate the following model, which shows that the piers should be drilled 3-15ft deep, depending on the location, to maintain a minimum safety factor of 1.87.
The solar panels are broken into four branches, each consisting of 1.95 MW connected to a 1.5 MW inverter and a 1500 A breaker. These 1500 A breakers are all contained in the switch gear, which can be used to isolate any branch for maintenance or in case of emergency. The inverters are used to convert DC from the solar panels to AC. The switchgear connects to a transformer which steps up the voltage to 13,200 V. From here, the output is ran 0.3 miles in an overhead line and connects to a 13.2kV bus in the existing substation. Digital relays are used to monitor the circuit.
Figure 7 shows the cash flows of our project for the life of the solar panel or 25 years as generated by SAM. Table 1 shows an economic summary of the project. The cost of electricity that Newmont is currently buying is a little over 9 cents per kW, so the cost was reduced by over 3 cents per kW.
Overall, the team achieved the original goal of the project. Newmont wants to reduce the cost of electricity, reduce carbon pollution caused by the plant, and show industry leadership. As shown above, the installation would reduce the cost of electricity from 9/kW to 6/kW. More importantly the site is estimated to offset 2,216.84 tons of CO2 annually. Furthermore, if Newmont was to act on the design quickly, they would become one of the earliest adopters of renewable energies in the mining industry.
93ddb68554