services
Geotechnical Subsurface Exploration & Evaluation
Geotech subsurface exploration is required in developing the conceptual site plan and final design to avoid any construction delays due to unforeseen subsurface conditions.
EEDAS has significant experience in providing high-quality services along with field challenges.
Geotechnical exploration and evaluation services include:
- Preliminary & final explorations (soil, rock boring, geoprobe, test pits etc)
- Soil laboratory testing consists of index testing, standard proctor compaction, california bearing ratio (CBR), pH and corrosion, direct shear, and unconfined compression test
- Field electrical resistivity & thermal resistivity testing.
- Recommendations include subsurface soil conditions, groundwater conditions, IBC seismic site classification, soil electrical & thermal resistivity, site preparation and earthwork, foundation design and construction, and site access roads.
Pile Testing & Evaluation
Pile testing is required for the final design of solar rack foundation. We also provide the rack foundation recommendations for unsuitable soil conditions (soft or rock soil areas) including geotechnical FEA analysis if required.
Pile Testing & Evaluation Services include:
- Pile testing under axial tensile (“pull-out” or uplift) load
- Pile testing under lateral load
- Pile testing under compression load
- Recommendations include suitable solar racking foundations per pile test and L pile analysis.
Geotechnical Engineering & Analysis
The EEDAS team has extensive experiences in predictive numerical analysis in geotechnical engineering. We have used pioneering geotechnical analysis software for our projects, for example, PLAXIS 2D/3D, GeoStudio, LPile etc. We have completed works on slope-stability of dams, excavations, settlement analysis of various structures, retaining wall design/retrofitting, Liquefaction analysis and 3D analysis of solar-panel based foundation.
Slope-Stability Analysis
Slope stability analysis is carried out by limit equilibrium method, using SLOPE/W and SLOPE 3D (GeoStudio). SLOPE 3D is a state-of-the-art method of slope-stability in 3D space, which is very accurate for relatively complex topography in a slope. The same is also solved by using the C-Phi reduction technique used by PLAXIS 2D and 3D. Compared the results to increase the reliability of the results and to understand the underlying mechanism of potential failure of the slope.
Fig. Slope-stability analysis of a slope by SLOPE/W & SLOPE3D of GeoStudio.
Fig. Retaining wall design in PLAXIS 3D.
Retaining Wall Design
Retaining wall design is a routine work in geotechnical engineering. A long-term design of a retaining wall needs static analysis as well as dynamic analysis (earthquake) to see the behavior of the retaining wall during the design period of the structure. This is achieved using PLAXIS 2D or PLAXIS 3D. We performed dynamic analysis followed by static analysis of the retaining wall to find out the design envelops of the bending moment/shear force in the retaining wall and ascertained the long-term safety of the wall.
Analysis of the Solar-Panel Foundation
In one of our solar panel foundation projects, one pile failed under proof tensile loading test, the surrounding soil of which was not injected with foam. We analyzed the full assembly of panel and piles to find out whether the failed piles could act better under group action with the torque tube and frames of the solar panels. We used PLAXIS (a finite element program) to simulate the group of piles (in a row) and then continued to do further analysis to find out a solution to this problem.
Fig. The FEM of the Pile group with frames of solar panels (Left), The Deformed shape on the Right.
Fig. Structural models of two high rise buildings (designed by ETABS) are imported into PLAXIS 3D and settlement analysis is carried out following the construction sequence of the buildings to find out the development of differential settlements (Left one). Settlement contours of the rafts of those two buildings (Right one).
Settlement Analysis
The design of every structure depends on the limited nature of the differential settlements at the base of that structure. With the help of the robust material models (Hardening soil, soft soil model, HB Model (rock)) of PLAXIS, it is possible to predict the differential settlement of a structure (short term and long term) and design the structure to withstand that settlement during the lifetime of the structure. We carried out an analysis of two buildings adjacent to each other to see the effect of construction (especially excavation of one to the other).
Dynamic/Static Liquefaction Analysis
Saturated fine particles can give rise to very high pore water pressure under an earthquake event and thus trigger an event of liquefaction under a foundation and damage the structure. We can easily determine the liquefaction potential or site response analysis using PLAXIS. There are two cyclic loading soil models, PM4Sand and UBC PLM 3D in PLAXIS, which can be used to predict any liquefaction related behavior of soil. There is also a static liquefaction model in PLAXIS (NorSand model) which can be used to predict the behavior of tailing dams.
