Foundation Design

BETA provides static and dynamic foundation design services for machinery, such as reciprocating compressors.  In addition to machine loads, we design for local soil conditions (soil allowable bearing capacity, static settlement guidelines), acceptable vibrations, and compatibility with the site characteristics such as frost heave potential.

In each project we optimize the dynamically loaded foundation by considering all types of foundations, including:

  • Concrete block
  • Gravel pads
  • Piles
  • Table top
  • Hybrid (concrete and piles)
  • Modular foundations (Steel structures, FPSO, offshore platforms)

BETA’s expertise in machinery design and dynamics, combined with in-house experts is unique. Few other firms have this broad focus.

Foundation services compliment BETA’s pulsation, mechanical, torsional, and skid design, resulting in an integrated solution.

Scope

  • Design and assess foundations for all types of machinery systems
  • Include all kinds of foundations (concrete, piles, gravel, platforms, etc.), new and old
  • Provide solutions to existing vibration problems
  • Account for geotechnical considerations at the site
  • Evaluate dynamic loading across all operating conditions

Features in BETA’s Approach

  • We accurately identify dynamic loads caused by equipment and soil – structure interaction effects under such loads.
  • For design projects, BETA works directly with the local geotechnical companies to identify soil conditions in their local area. The analysis includes the assessment of the foundation’s natural frequency, damping, resonance, and the impact on vibration and dynamic stress for existing foundations. For existing foundations, field measurements define the problem and help us to define soil properties.
  • We accurately calculate dynamic response due to foundation natural frequencies and dynamic forces from the machinery.
  • We provide a recommended foundation design to limit vibration to safe levels.
  • We provide installation recommendations.

Compressor Foundation Design
Compressor Foundation Design (installation and field testing)

 

Dynamic Foundation Analysis
Dynamic Foundation Study: Model of compressor skid and pile foundation

 Inadequate Foundation
Example of cracks, oil impregnation, and vibration problem due to inadequate foundation
 
 

BETA’s range of software tools are used for

  • Dynamic study of rigid, flexible and pile foundation under harmonic, transient and random loading.
  • Geotechnical modeling of the soil mass, damping and stiffness characteristics.
  • Analysis of steel and concrete structures exposed to lifting loads, quasi-static environmental loads (e.g., wind, transit, storm, earthquake), and dynamic loads.
  • Operating Deflected Shapes (ODS) on foundation repair/troubleshooting projects.
  • Structural design of foundations, including concrete blocks and piles.

Customer Benefits

  • Optimization of the foundation design based on foundation performance and construction costs
  • Elimination of foundation failures –  extremely costly problems for owners
  • Dynamic foundation design – an integral element of a vibration mitigation strategy
  • Lower maintenance costs and improved safety –properly designed foundations reduce stresses on bearings
  • Reduced failure of auxiliary equipment including small bore attachments

BETA Advantages

  • Combination of geotechnical engineering with in-depth knowledge of machinery behavior
  • Comprehensive machinery and foundation models
  • Extensive field experience resolving existing foundation problems
  • Inclusion of dynamic loads from equipment (gas rod loads, unbalance, pulsation-induced forces in vessels, etc.)
  • Database of detailed reciprocating compressor models to accurately simulate system loading and response. Models have been verified with field testing

Representative Project List: Our team has experience field troubleshooting, designing, implementing, and managing large and small foundation projects.

> Click here to see a representative customer list.

 

Skid, Compressor and Foundation Analysis
Skid, Compressor and Foundation Analysis

Top view of Operated Deflected Shape
Top view of Operating Deflection Shape 

 Side View of Operated Deflected Shape

 Side view of Operating Deflection Shape

  Examples of Beta's Field and Design Capabilities for Foundations: 
Inspection of Pile Gravel Foundation Pile Supported Foundation
Inspection of pile - skid connections as a part of modification to an existing foundation (to increase dynamic stiffness) 

Example 1Gravel foundations impacts vibration
High vibrations were measured on the skid and compressor package. An Operating Deflected Shape (ODS) analysis determined that there were several local bending modes of the compressor skid as well as many modes of the piping, vessels and compressor cylinders in the range of the first and second order of compressor speed. Soil and gravel pad properties were evaluated with the compressor skid model to address the resonant condition.

 

Example 2Torsional vibration on piles
When a pile supported compressor foundation was experiencing excessive torsional vibrations, we were able to mitigate these vibrations without using additional piles or imposing very high cost for removal of the compressor skid from the top of piles and moving it back. Using a unique solution, we increased the torsional stiffness, resolving the foundation vibration problem at a fraction of the expected cost.