Geotechnical Engineering

Steel and concrete are manmade materials whose properties can be altered by design. In contrast, subsurface soil and rock properties are heterogenous and vary widely, affecting the performance of structures they support. Presence of water in these materials adds another level of complexity, sometimes assisting and at other times devastating. Keeping this in mind, engineers at DESI are trained to understand the theory of material, appropriate methods of investigation, review pertinent project information, perform project specific evaluation to enable development of ideal solutions to develop foundations, estimate settlement, slope stability, ground improvements, etc. Geotechnical Investigations are essential during the feasibility phase to develop a design complying with regulations, allocate appropriate budget to avoid future cost overruns and avoid delay in project delivery. To ensure success of the projects, DESI recommends appropriate investigation tailored with proposed development for the clients. Often DESI recommends combining geotechnical and environmental investigations as significant information obtained can be used by both disciplines.

Geotechnical engineers constantly deal with varying sub-surface soil, rock, and ground water conditions and developing ideal design parameters is beyond basic review of soil boring records and SPT values. DESI engineers will derive optimum design parameters keeping all aspects of the project in consideration. Depending upon the need, special studies such as seepage analyses, ground stabilization, and pre-consolidation are also conducted. Under the guidance of founder and president of the company Ram Tirumala, P.E., a geotechnical engineer with MS in Geotechnical Engineering from NJIT, DESI has successfully completed many innovative geotechnical projects.

DESI soil laboratory plays an integral part in our geotechnical department, providing an opportunity to undertake, index, and engineer properties of soil encountered in the field.

Services offered include:

  • Subsurface Investigations
  • Settlement, Slope Stability Analyses
  • Shallow & Deep Foundation Design
  • Drilled-in Caissons, mini piles
  • Driven Piles, WEAP Analysis, CAPWAP
  • Waterfront Structures, Piers and Bulkheads
  • Soil and Rock Slope Stability Analyses
  • Landfill Slurry Walls, Jet Grouting, Capping
  • Sheeting, Soldier Pile and Lagging
  • Excavation Support
  • Tunnels / Microtunneling
  • Horizontal Direction Drilling
  • Construction Documents
  • Peer Review
  • Pre-Construction Condition Surveys
  • Engineering Services during Construction

NJTPK Interchange 14A – Bayonne and Jersey City, NJ

DESI is supporting the Gannett Fleming’s team for Final Design Services of the $350 million improvements at Interchange 14A. DESI was retained to prepare and implement the Subsurface Exploration Program, including preparation of the boring contract, retaining a contractor, and oversight of roughly 200 soil borings, collection of rock cores, evaluation and classification of materials, oversight of borehole in-situ permeability tests  estimating infiltration properties for the design of stormwater management facilities; and obtaining observation well groundwater readings through instrumentation. DESI also prepared reports for a foundation of a Retaining Wall and all of the Sign Structures.

NYCDOT – Belt Parkway Reconstruction, Brooklyn, NY

DESI was retained by TPJV (Tully Possilico JV) to provide geotechnical engineering services and monitoring. DESI performed geotechnical investigations of liquefiable soils, slope stability analysis using SLIDE software, and developed the Geotechnical Data Report. DESI also performed settlement analyses to estimate the magnitude of settlement for roadway embankments, drawdown loads on piles, and the effect of surcharge to accelerate consolidation settlement. Work performed by DESI was reviewed and approved by a diverse project team of designers from NYCDOT. DESI’s approach allowed the client to reduce the construction duration by 6 months. DESI won ACEC NY 2014 “Gold” Engineering Excellence Award.

NYCEDC – Rockaway Boardwalk Project, NY.

DESI was retained by CH2M Hill to evaluate the existing condition of the Boardwalk structure following Super Storm Sandy.  DESI adopted a unique method to evaluate 4800 existing piles using nondestructive testing techniques saving considerable amounts of money and time. DESI retained a pile driving subcontractor to restrike selected existing concrete piles and drive new H test piles along the Boardwalk alignment. DESI also performed pile integrity tests for approximately 25% of the total existing pile bents. DESI provided the Pile Capacity Reports and determined existing pile depths. DESI won ACEC NY 2015 “Diamond” Engineering Excellence Award.

NYC EDC & NYC DEP Green Infrastructure Program

DESI is assisting ARUP with the Hazardous Materials Testing Program; Vault Surveys; Geotechnical Investigations and Evaluations including planning, project management and full-time site supervision of a Subsurface Investigation Program that includes in-situ permeability testing and laboratory testing; prepare geotechnical data report; and support in engineering design services through construction. DESI is working on about 600 locations at Newtown Creek, 350 in West Chester Creek, and 600 more in Bowery Bay