PLAXIS 3D transforms geotechnology into accurate and reliable simulation. This Bentley Systems software (Seequent) allows engineers to predict the behaviour of soils and structures associated with 3D finite element analysis. Recent examples, from Japan to Singapore, illustrate how this tool transforms the design of the most demanding infrastructure projects.
In brief:
- In Fukushima, a PLAXIS 3D model confirmed a previously underestimated risk of liquefaction on silt soil.
- In Madrid, PLAXIS 3D validated the digging of a subway tunnel with only 3 meters of clearance under another infrastructure.
- In Hong Kong, PLAXIS 3D saved $16 million and 2 months of construction on a 5 km underwater tunnel.
- In Singapore, PLAXIS 2D secured an 18-metre deep excavation near the longest bridge in the country.
- beCAD, Bentley Systems partner, supports sales, advice and training on PLAXIS 3D.
What is PLAXIS 3D?
PLAXIS 3D allows geotechnical engineers to carry out advanced 3D finite element analyses for ambitious projects in the civil, mining, energy and environmental engineering sectors: excavations, surface foundations, piles and offshore, embankment, improvement of soils and tunnels, taking into account static, dynamic or seismic loads as well as complex hydrological conditions.
Predict the behaviour of the soil before the first shovel.
Four recent megaprojects informed by PLAXIS 3D
From underwater tunnels to skyscrapers on soft clay, PLAXIS replaces the hypotheses by simulation: it does not just validate designs, it optimizes them.
Triple Earthquake in Fukushima, Japan
After the great earthquake of 2011 and the tsunami that followed, the reconstruction of a plant on silt soil posed a challenge: this type of soil is notoriously difficult to model. By combining a PLAXIS 3D model with seismic recordings of neighbouring sensors, engineers simulated the building's behaviour through the three earthquakes. The model not only replicated the observed settlements, but also confirmed a liquefaction phenomenon previously considered unlikely.
Madrid Metro Line 5, Spain
The challenge: pass a new tunnel between the existing metro line 8 and the embankment of the M-11 motorway, with only 3 meters of clearance at the narrowest point. Thanks to a soil-structure interaction model incorporating more than 400 construction phases, PLAXIS 3D demonstrated that the tunnel could be safely excavated by excavating the face in 1.25 metre short segments, limiting ground movements.
Each digging phase can be simulated to anticipate ground movements.
Hong Kong's deepest underwater tunnel
At a cost of $2.33 billion, the Tuen Mun-Chek Lap Kok Link (Southern Landfall) tunnel is a 5 km deep and longest underwater road tunnel in the city. In the face of complex geotechnical conditions (alluviations, marine deposits, thick sand embankment, high water pressure), the use of PLAXIS 3D reduced the number of barlets required by 52 and reduced 46 barlets by an average of 2.8 metres: $16 million saved, 2 months of construction earned and about 1,500 tons of CO2 less.
Marina Bay Sands, Singapore
One of the country's largest and deepest urban excavation sites: a basement of 18 metres deep in soft marine clay, near the Benjamin Sheares Bridge, Singapore's longest bridge. PLAXIS simulation revealed that lateral ground movement would exceed the safety limits of fixed bridge links. Rather than trying to eliminate any movement, engineers adapted the bridge itself, replacing three fixed links with adjustable joints capable of tolerating the predicted movement.
The 10 key points of PLAXIS 3D
| Key point | In practice |
|---|---|
| 1. 3D finite element analysis | Comprehensive assessments of soil and rock deformation and safety. |
| 2. Excavations and foundations | Surface foundations, piles, offshore structures. |
| 3. Soil embankment and improvement | Modelling of land enhancement measures. |
| 4. Construction sequences | Easy generation and adaptation of tunnel digging phases. |
| 5. Static, dynamic, seismic loads | Full consideration of the stresses on the ground and structures. |
| 6. Complex hydrology | Underground flows and temporal variations in water level. |
| 7. Multicore Solver (Advanced) | Faster calculations for flow-deformation coupling. |
| 8. Vibration analysis (Ultimate) | Earthquakes, pile beating, traffic, heavy machinery. |
| 9. Wide range of materials models | Prediction of behaviour of various types of soil and rocks. |
| 10. Multidisciplinary workflows | From importing data from the basement to producing deliverables. |
The soil-structure interaction, from pile to complete structure, to the heart of PLAXIS 3D.
Frequently Asked Questions
What is PLAXIS 3D for?
PLAXIS 3D is used to analyze the deformation and stability of soil and rock by 3D finite elements for excavation, foundation, tunnel or embankment projects, taking into account static, seismic and hydrological loads.
What is the difference between PLAXIS 3D, Advanced and Ultimate?
PLAXIS 3D covers current deformation and safety analyses. Advanced adds flow-deformation coupling, consolidation analysis and a multicore solver. Ultimate extends these capabilities to vibration analysis and to complex and variable hydrological conditions over time.
Can PLAXIS 3D model an earthquake?
Yes. The Ultimate editions analyse the effects of seismic or traffic-induced vibrations and heavy machinery, as well as soil response and liquefaction analyses.
Is PLAXIS 3D suitable for high-risk urban tunnels?
Yes: as illustrated in Madrid, PLAXIS 3D allows to model hundreds of construction phases and validate very precise excavation sequences to protect neighbouring infrastructures, even with minimal clearance.
Why choose PLAXIS 3D with beCAD?
As an approved Bentley Systems partner, beCAD supports geotechnical engineering and engineering offices in consulting, selling and training on PLAXIS 3D and all Bentley solutions (MicroStation, OpenRoads Designer, OpenBuildings Designer, iTwin Capture Modeler...). Our team helps you secure your most demanding geotechnical projects.
