There are a wide range of geotechnical engineering problems that fall under the broader category of civil engineering works. These can often involve the construction of roadways, rail beds, bridge abutments, and mechanically stabilized earth (MSE) walls. The challenges associated with designing these structures are varied. Construction sequences in the field often depend on transient changes in pore-water pressures due to consolidation. Embankment construction often requires the interaction of typical soil materials as well as concrete and structural steel or geofabrics. Timing of the placement of these components is often critical to construction and post-construction stability.
GeoStudio is capable of analyzing many different construction projects. Staged construction can be modeled in the same sequence as actual field construction and if the process is time dependent, such as waiting for dissipation of excess pore-water pressures, then it is possible to set actual time durations to the modeled stages so that the results over time can be graphed and analyzed. Data from one construction stage to the next is automatically carried forward and it is possible to branch the analysis to consider different scenarios that both depend on the same previous stage analysis results. In addition, the integration capabilities in GeoStudio allow for a wide range of supporting analyses to be added to the project at any time, such as slope stability, ground freezing, climate interaction, or earthquake stability.
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In the 1970’s, a series of test embankments were constructed on soft clay at Cubzac-les-Ponts in France. These full-scale field tests were well-instrumented and are well-documented, and consequently provide an excellent case history. Two of the embankments are the subject of this article.
GSZ:(1) (2) PDF
SLOPE/W can be used to complete a stability analysis with the objective being to check an ultimate limit state in accordance with various limit state design approaches such as Eurocode 7, Norwegian Standard NS 3480, and British Standard 8006. The stability analysis is completed with partial factors applied to characteristic loads and soil strength parameters.
GSZ:(1) (2) (3) PDF
The purpose of this example is to show how geosynthetic reinforcement (e.g. geogrid and geotextile) is accommodated in a stability analysis. The example file uses multiple SLOPE/W functionalities including distribution of the pullout forces across many slices, factor of safety dependency option for geosynthetic reinforcement, load orientation and more.
This example is about constructing an embankment in delayed stages on a soft foundation so that some of the excess pore-pressure is allowed to dissipate before subsequent lifts are placed. The soft foundation is modeled using the non-linear Modified Cam-Clay (MCC) constitutive relationship.
SLOPE/W is the leading slope stability software for computing the factor of safety of earth and rock slopes. SLOPE/W can effectively analyze both simple and complex problems for a variety of slip surface shapes, pore-water pressure conditions, soil properties, analysis methods and loading conditions.
SEEP/W analyzes groundwater flow within porous materials such as soil and rock. Its formulation enables analyses ranging from simple saturated steady-state problems to sophisticated saturated/unsaturated time-dependent problems.
SIGMA/W performs stress and deformation analyses of geotechnical, civil and mining works. It can perform a simple linear elastic deformation analysis or a highly sophisticated soil-structure interaction analysis with non-linear material models and coupling to seepage analysis.
QUAKE/W enables dynamic analysis of earth structures subjected to earthquake shaking, or point dynamic forces from a blast or a sudden impact load. It determines the motion and excess pore-water pressures that arise due to shaking.
TEMP/W enables analysis of thermal changes in the ground due to environmental factors or the construction of facilities such as buildings or pipelines. TEMP/W can be applied to the geothermal analysis and design of geotechnical, civil, and mining engineering projects.
AIR/W analyzes groundwater-air interaction problems within porous materials such as soil and rock. It enables analyses ranging from simple, single-phase air-transfer analyses to complex coupled air-water systems.
VADOSE/W analyzes interactions at the ground surface to determine environmental impacts on the movement of water through the unsaturated vadose zone and into the local groundwater regime. Potential interactions considered in VADOSE/W include infiltration due to rainfall and snowmelt, root transpiration, gas diffusion, and surface runoff, evaporation and ponding.