W. David Dennis, Jr., P.E.
M.S./Geotechnical Engineering/1975/University of California, Berkeley
B.S./Civil Engineering/1971/Mississippi State University
Professional Engineer: Mississippi and Louisiana
Burns Cooley Dennis, Inc., Senior Consultant, October 2017 – Present
Burns Cooley Dennis, Inc., Principal, December 1990 – October 2017
Burns Cooley Dennis, Inc., Senior Geotechnical Engineer, June 1990 – November 1990
Woodward-Clyde Consultants, Manager of Geotechnical Division, Baton Rouge, Louisiana, March 1987 – May 1990
Burns Engineering, Inc., Geotechnical Engineer, June 1985 – February 1987
Ware Lind Engineers, Principal, 1980 – May 1985
Ware Lind Engineers, Geotechnical Engineer, 1978 – 1980
U.S. Army Corps of Engineers, Vicksburg District, Vicksburg, Mississippi, 1971 – 1978
Background. Mr. Dennis has over 46 years of experience in the geotechnical engineering profession. Prior to his return to Burns Cooley Dennis, Inc., in 1990, he served for three years as Manager of the Geotechnical Division of Woodward-Clyde Consultants’ Baton Rouge, Louisiana office. Before joining Woodward-Clyde Consultants, he was associated with Ware Lind Engineers and Burns Engineering of Jackson, Mississippi. Prior to that, he was an employee of the U.S. Army Corps of Engineers, Vicksburg District, in the Foundation and Materials Branch.
Corps of Engineers Experience. As an employee of the Vicksburg District, Corps of Engineers (COE), Mr. Dennis was responsible for the completion of all phases of soils analysis and soil mechanics design of dams, navigation locks and dams, flood and retaining walls, channels, levees, revetments, drainage structures, pumping stations, ports, seepage and stability berms, etc. Mr. Dennis is knowledgeable of COE analysis criteria governing slope stability, underseepage and dewatering, sliding stability of structures, settlement of structures, and foundation design. He has experience in the use of computer-aided geotechnical analysis techniques. Mr. Dennis is knowledgeable of COE criteria for soil sampling, soil classification and laboratory testing.
Structure Foundations. Mr. Dennis has completed numerous foundation investigations for commercial and industrial single and multi-story structures. These investigations have included analyses and recommendations for shallow footings, driven piles, drilled piers, and for special foundation elements to support structures upon highly expansive soils. Foundation studies completed by Mr. Dennis have also included detailed analyses to determine long-term settlements within fill and natural materials and rebound/swell movements within expansive clays. As examples of his foundation engineering experience, Mr. Dennis conducted geotechnical investigations for a major industrial plant expansion on the Gulf Coast in DeLisle, Mississippi, and for a large Nissan vehicle assembly plant near Canton, Mississippi. Those investigations included extensive subsurface exploration programs, laboratory testing, evaluations of shallow foundations and deep foundations for heavily loaded structures, design analyses for light and heavy-duty pavements, and recommendations for construction of railroad spur embankments. Mr. Dennis has been involved in the monitoring of earthwork and foundation construction for various projects.
Utilities and Towers. Mr. Dennis has performed geotechnical investigations for utilities such as sewer lines, substations and transmission lines. The sewer line investigations have included exploration of subsurface soil and foundation conditions along the proposed alignment of sewer pipes, and at manhole and lift station locations; the performance of laboratory tests to investigate soil classifications, moisture content variations, and pH and resistivity properties of the soils that are indicative of corrosiveness; and the preparation of engineering reports including recommendations concerning excavation and dewatering, pipe bedding material, select backfill, compaction of backfill soils, and foundations for lift stations. Mr. Dennis has performed foundation investigations for substations, transmission lines, microwave and television towers. Mr. Dennis has also performed investigations for lighting systems including high-mast poles requiring single foundation elements subjected to significant moment and lateral loads.
Earth Dams. Mr. Dennis is experienced in the performance of slope stability and seepage analyses for dams. He has completed slope stability studies for Roosevelt Lake Dam, Lake Tangipahoa Dam and Whitens Creek Dam. Analyses for the Lake Tangipahoa Dam and Whitens Creek Dam included an assessment of embankment through seepage and underseepage and the design of a downstream seepage berm. Mr. Dennis was the geotechnical representative on the team of specialists charged with the inspection and review of earth dams throughout the State of Mississippi under the National Dam Inspection Program.
Slides. Mr. Dennis has conducted investigations for numerous earth slides. Many of the slides were found to have occurred progressively under long-term conditions within very stiff to hard, slickensided clay soils. The field exploration phase of the slide investigations typically included continuous sample borings and the installation and monitoring of piezometers and slope inclinometers. For each slide investigation, the soil boring information, piezometer and slope inclinometer data were utilized in slope stability analyses to determine the effective stress strength parameters which would produce a factor of safety of 1.0 along the failure plane. Then stability analyses were performed to assess the feasibility of remediating the slide by means of alternative techniques such as berms, subsurface drainage, stone columns, etc.
Gaming Facilities. Mr. Dennis conducted a geotechnical investigation for a major dockside gaming facility constructed along the eastern bluff of the Mississippi River in Vicksburg, Mississippi. The investigation included: 22 exploratory soil borings, six of which were made in the river; installation and monitoring of seven piezometers with tips set in various formations; laboratory testing; and extensive slope stability analyses for the planned facility configuration which required relatively deep excavations into the existing loessial soil slopes along the bluff. For construction, inclinometer casings were installed and monitored on a daily basis for ground movements. Other construction monitoring services included earthwork, concrete and asphalt testing.
Pavements. Mr. Dennis has conducted pavement investigations for numerous roadways and parking areas. He is familiar with the AASHTO Guide for Design of Pavement Structures and has utilized the procedures included in this guide to develop design curves for flexible pavements consisting of full-depth asphalt concrete and asphalt concrete underlain by a gravel base course. Design curves were also developed for the inclusion of a geotextile stabilization fabric beneath the base course materials. Mr. Dennis conducted geotechnical pavement investigations for a major trucking terminal for Con-Way Southern Express in Richland, Mississippi, for improvements to East County Line Road in Ridgeland/Jackson, and for the Wynndale Industrial Park.
Landfills. Mr. Dennis has participated in geotechnical analyses and design for hazardous and solid waste landfills. This work involved: slope stability analyses; investigations of groundwater seepage and cell bottom heave; settlement analyses; design of leachate collection/removal systems and liners; and the preparation of plans and specifications. Mr. Dennis’ experience with landfills includes: a hazardous waste landfill with a triple composite liner system for an industrial facility in Lake Charles, Louisiana; a nonhazardous industrial solid waste landfill for the Oxy Chemical facility near Convent, Louisiana; a proposed solid waste landfill to be constructed in relatively weak natural soil deposits with high groundwater levels at a site in St. James Parish, Louisiana; a Waste Management, Inc. municipal solid waste landfill located near Walker, Louisiana; and the municipal solid waste landfill in West Carroll Parish, Louisiana.
Papers. Mr. Dennis co-authored a paper entitled “Effect of Load Form and Sample Reconstitution on Test Results” which was presented at the Earthquake Engineering and Soil Dynamics Specialty Conference held in Pasadena, California, in June 1978.
AFFILIATIONS, HONORS AND AWARDS
American Society of Civil Engineers
National Society of Professional Engineers
Mississippi Engineering Society
Louisiana Engineering Society
American Council of Engineering Companies
Tau Beta Pi
Phi Kappa Phi
Award of Merit, Mississippi Section, ASCE, 1971
Secretary-Treasurer, Vicksburg Branch, ASCE, 1976-1977
President, Jackson Branch, ASCE, 1982-1983
President-Elect, Mississippi Section, ASCE, 1984-1985
President, Mississippi Section, ASCE, 1985-1986