EEI geotechnical engineers have over 30 years of extensive experience practicing in the region that gives us the ability to provide cost effective solutions to complex problems. We have compiled an extensive database of projects & data that allows us to pull information to aide in our evaluations. With thorough site investigations and characterizations we are able to perform analyses and provide recommendations for foundation types and allowable bearing capacities for any type of structure.
We routinely develop foundation recommendations for various types of projects including commercial, industrial, residential and infrastructure. Shallow foundation bearing capacity calculations are performed for all of our projects. Recommendations are developed whenever they are feasible in order to provide cost effective foundation solutions. When shallow footings are not feasible, we then expand our analyses to intermediate, ground improvements, and deep foundation systems.
However, the determination of the bearing capacity for a structure to prevent failure is only part of the picture. The allowable bearing capacity for a structure is predominately governed by the amount of settlement (vertical deformation) that any given structure can tolerate. Estimation of the settlement of a proposed structure is critical to being able to provide an allowable bearing capacity. The weight and configuration of the structure and, of course, the subsurface conditions are major factors in this evaluation. Some of the items that need to be considered are:
- Total settlement
- Differential settlement
- Rate of settlement (Saturated fine-grained silt and clays)
- Angular distortion
Different soil types and foundation types will behave in much different manners, and different structures have different settlement tolerances. All structures settle to some degree. It is our job to make sure that these settlements are within tolerable limits. Examples of allowable settlements are shown below.
Type of Movement | Limiting Factor | Maximum Settlement |
---|---|---|
Total Settlement | Drainage | 6-12 in. |
Access | 12-24 in. | |
Probability of Nonuniform Settlement | ||
Masonry Walled Structures | 1-2 in. | |
Framed Structures | 2-4 in. | |
Smokestacks, Silos, etc. | 3-12 in. | |
Tilting | Stability Against Overturning | Depends on H & W |
Tilting of Smokestacks | 0.004L | |
Rolling of Trucks | 0.01L | |
Stacking of goods | 0.01L | |
Machine Operation – Cotton Loom | 0.003L | |
Machine Operation – Turbogenerator | 0.0002L | |
Crane Rails | 0.003L | |
Drainage of Floors | 0.01-0.02L | |
Differential Movement | High Continuous Brick Walls | 0.0005-0.001L |
One-Story Brick mull Building, Wall Cracking | 0.001-0.002L | |
Plaster Cracking (Gypsum) | 0.001L | |
Reinforced-Concrete-Building Frame | 0.0025-0.004L | |
Reinforced-Concrete-Building Curtain Walls | 0.003L | |
Steel Frame, Continuous | 0.002L | |
Simple Steel Frame | 0.005L |
Some of the tools we use range from classic bearing capacity analysis initially developed by Terzaghi with modifications to finite difference programs for more complex projects that involve unique or overlapping loads due to proximity of foundations as shown in the illustrations below.
The key element in all of our analyses is in estimation of the soil properties. In addition, often times we are engaged in the early planning stages of a project and need to use our experience and judgement estimating building loads and configurations. Since these factors change as the project evolves, EEI can provide value and potential significant cost savings if we are provided the opportunity to review the structure foundation designs at the latter part of the design process.
Earth Engineering conducts Bearing Capacity and Settlement Analysis testing in PA, NJ, and Delaware. Contact one of our directors or project managers at any of our 4 locations to discuss your subsurface investigation needs and how Earth Engineering Inc. can help.
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