STEGMAN ENGINEERING, PC

In addition to Geotechnical & Foundation Engineering for tower related projects; we have over 20-years experience in a wide variety of projects including interstate roadways and bridges, structures with shallow and deep foundations, retaining walls, underpinning, embankments, stability analyses, tie-backs, failure investigations, and of course foundation analysis of existing and proposed towers. Contact us at: Geotechnical

Key Areas

Geotechnical & Foundation Engineering

We endeavor to provide innovative yet practical solutions to geotechnical and foundation engineering problems for new and existing structures. We use routine methods such as standard penetration test borings and NX/NQ rock coring to advanced techniques including in-situ testing, instrumentation, and geophysical surveys.

We are completely mobile. We use 4WD vehicles equipped with Global Positioning Systems (GPS); Laptop computers; cellular phones, nationwide toll-free pagers; and the Internet for email and data transfer.  Stegman Engineering serves clients from Florida to New York including architects, engineers, developers, and contractors.

In-situ testing such as the Dilatometer or Pressure Meters allows for a direct evaluation of the engineering characteristics, which permits a more rationale foundation design. The field data is analyzed and provides the geotechnical parameters such as soil type, coefficient of earth pressure (at rest), preconsolidation pressure, undrained shear strength (for clays), angle of internal friction (for sands), and one dimensional (constrained) modulus.

Using conventional drilling, in-situ testing, and or nondestructive testing, Stegman Engineering can analyze existing foundations for capacity to determine the potential for expanding existing buildings, bridges, towers, etc.  In some case, we have determined that certain foundations have reserve capacity of up to 50%, meaning that in some instances, foundation retrofits may not be a necessary part of the client’s cost for expanding an existing structure.

Contact us at: Geotechnical

Unknown Foundations

Using Non-Destructive-Evaluation methods and/or other methods, Stegman Engineering is offering geotechnical and structural analysis of unknown foundations using:

This method of testing uses "Dispersive Wave" or flexural waves of bending, and does not suffer signal loss for long slender piles (whereas pulse echo techniques do).

Lateral capacity of drilled shafts is strongly controlled by the reinforcement. We analyze the foundations using LPILE^PLUS that fully considers the non-linear behavior of the soil and concrete.

GPR is limited in areas of shallow ground water, especially if ground water has salt.

To provide a complete analysis of existing foundations, Stegman Engineering supervises the field exploration directly such that field data can be analyzed on site so:

If foundation rehabilitation is required, Stegman Engineering can restructure our report to provide "performance" guidelines that the Owner can use to acquire specialty contractor proposals.

Contact us at: Geotechnical

Non Destructive Methods

Faced with prolonging the life of our aging infrastructure because of prohibitive replacement costs, assessing existing conditions becomes a critical Stegman Engineering. Non-Destructive-Evaluation are non-damaging, non-invasive testing techniques; the major advantages reducing or eliminating disturbance and restoration costs, but also quick turn-around time. With continually improving technology, the relative cost of NDE becomes less over time. Some of the more common problems frequently solved using NDE:

Contact us at: Geotechnical

Pile/Caisson Length Determination or Integrity Testing

Stegman Engineering is offering a new type of technology that can be used to determine the length of unknown foundations, or perform integrity testing on known foundations. This method uses "Dispersive Wave Technology" developed by FDH, Inc., and can be performed using either top or side impact.  This technology has been used for length/Integrity testing of:

Dispersion is the phenomenon by which waves in a material continuously change their shape and elongate as time passes. This is caused by different frequencies inside a wave traveling at different speeds. (Even minor changes in frequency velocities cause dispersion.) Dispersive wave behavior is a result of the geometry of the material through which the wave travels. Near one end of the spectrum is the earth, through which waves travel and are considered non-dispersive. Near the other end of the spectrum are rods that have small diameters and are long, yet finite, in length. As a pulse travels through a rod, after being created by an end strike, the many frequencies in the wave reflect and refract from the rod’s sides, its end, and any material anomalies. This causes dispersion of the wave since the frequencies’ motion are interrupted, and thus some of these travel to the rod’s end where they reflect and return to the surface, while others never make it to the rod’s tip at all.

The classical wave equation, often called the traditional wave solution, does not account for dispersion. It is an ideal mathematical description of the pulse’s behavior, with its solution saying that a wave will travel through a rod without ever changing its shape or elongating. This is the difference with dispersive signal analysis; dispersive analysis of the wave data to extracts a selected group of frequencies. These frequencies then are analyzed for the individual times in which they require to travel to the pile’s tip and back or from their tops to the location of an area of damage such as a void, break, soil intrusion or material deterioration.

It is this type of analysis that allows testing of piles with a high Length to Diameter ratio. To date, limiting L/D ratio have not been encountered, tested and successfully analyzed data from 14-inch diameter, 90 foot long auger cast piles. There will be a limiting L/D ratio, but it has not yet been encountered since our methods of testing account for the ever-present characteristic of dispersion.