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By Travis Coleman, Elvis Ishimwe

Currently, more than 400 drilled shafts have been constructed by various contractors at the I-90/94 and I-290 Jane Byrne (Circle) Interchange, located near downtown Chicago, Illinois. Cross-Hole Sonic Logging (CSL) and Thermal Integrity Profiling (TIP) tests were performed to evaluate the integrity and concrete quality of the drilled shafts installed at this project. For Phase I of the project the shafts were tested using CSL methods, and the shaft integrity was identified by analyzing the First Arrival Time (FAT) and the signal strength (energy) measurements. For the major portion of Phase II, the Illinois Department of Transportation (IDOT) accepted TIP testing as a substitute for CSL at the request of the contractors. The CSL testing results indicated 54 percent of the tested shafts had anomalies, and 78 percent of these anomalies were located within the lower three diameters of the shafts. To date, TIP testing results indicated the shaft integrity was as expected and acceptable for the all 34 tested shafts. A review of the testing results and a discussion of the detected anomalies are presented. In addition, a comparison of both TIP and CSL measurements is presented in this paper.

By Jamey Rosen

A Project Information Management System (PIMS) was developed to manage and analyze QC data at the Herbert Hoover Dike Rehabilitation Dam Modification Cutoff Wall (owned by the Jacksonville District of the United States Army Corps of Engineers). A special feature of this PIMS was its geospatial component. Data collected from Bauer drill rigs were automatically “geoprocessed” into threedimensional features representing the predrill, jet grout, and Cutter Soil Mixing panel elements, as well as calculated verticality and overlap metrics. These features were visualized in interactive planimetric, profile, and 3D views that facilitated several quality control activities during the project.

By Jason Herron, Joseph Brown

The common couplings for joining sections of helical piles with an outside diameter of 6.625 inches and 8.625 inches are square on square, flange to flange, external pipe sleeve, internal pipe sleeve, and welded joint. Each coupling type has advantages and disadvantages in efficiency, capacity, installation, and economics of the installed pile. All these coupling types have been used in the helical pile market in North America for various applications and designs. Many of these applications require on-site testing, but test records are not typically shared with the helical pile industry. Due to the lack of information available for square on square and flange to flange couplings, testing was done to compare the efficiency of installation, load to deflection response, and torque to capacity ratios of external pipe sleeve, square on square, and flange to flange couplings. Field installations and tension tests were performed in non-cohesive (sand type) soil near Caseyville, IL and in cohesive (clay type) soil in Centralia, MO. The data collected during these tests included rotations per foot during installation, installation torque, applied pressure, and deflection. The results of this testing are analyzed and discussed within this paper. The results indicate that the square to square coupling is the most efficient of the designs tested, but this conclusion cannot be fully justified without further testing due to the variability in the data gathered and the small number of piles tested. INTRODUCTION A helical pile is typically assumed to be a medium-displacement pile when its outside diameter is between 4.5 inches and 8 inches and a high-displacement pile when its outside diameter is greater than 8 inches. A helical pile designer has multiple options when selecting a coupling type for medium- to high-displacement helical piles. Each type of coupling has advantages and disadvantages and must be analyzed on the bases of efficiency, capacity, installation, and economics of a project. Typical couplings that are chosen by designers include square on square, flange to flange, external pipe sleeve, internal pipe sleeve, and welded joint. A helical pile must transfer axial, lateral, bending moment, and torsional loads, and the coupling must be designed to effectively and efficiently transfer each type of load. During the installation of a helical pile, the rate of penetration and the disturbance of soil layers play a critical role in the efficiency and torque to capacity ratio (Kt) of the pile. It is common for a coupling to protrude beyond the outside diameter of the pipe section being used. This is necessary for the function of certain coupling types and can facilitate the connection of couplings. However, it causes increased soil disturbance and reduce the rate of penetration due to soil bearing against the protruding portion of the coupling. A helical pile designer typically will work to minimize the coupling protrusion and create a pile with optimal installation efficiency but may choose a design with lower installation efficiency if it offers sufficient economic advantage.

Jan 1, 2019

By Christian L. Escalera

Over seven years ago, on October 29, 2012, Superstorm Sandy pummeled the Northeast of the United States inflicting heavy damage on New York City Transit’s (NYCT) system. Since then, NYCT has been methodically rehabilitating and hardening its assets to upgrade service and prevent future impacts caused by similar devasting storm surges. Part of these resiliency efforts, NYCT’s 207th St Yard Project is one of many projects that make up the Sandy Repair and Flood Mitigation Program. The work to be performed on the 207th Street Project includes building a perimeter Floodwall along the Harlem River, extending up 215th Street and 9th Avenue with the intent of having the ability to withstand a 500 Year Storm flooding event. The original 1,535 lineal feet of the marine side floodwall design consisted of 937 each W40x235 H-Piles continuously welded to PS 27.5 flat sheet to form an interlocked and composite steel seawall that would protect the NYCT 207th Yard from a storm surge of the Harlem River. However, after the Contract was awarded and a Notice to Proceed was issued, Walsh Construction Company II (WCCII) partnered with Mueser Rutledge Consulting Engineers (MRCE) to propose a redesign of the marine wall section as a Value Engineering Change Proposal (VECP). This VEP redesign is comprised of 279 each 54in Diameter Steel Pipe Piles that are interconnected with continuously welded PZ 35 sheet piles interlocks. The intent of the VEP was to provide a cost savings that could be shared by both parties as well as alleviate some constructability and alignment control concerns that WCCII had expressed to NYCT. The VEP allowed WCCII to substantially lower the total cost which was shared between NYCT and WCCII.

By Alex Ryberg, Matthew L. Becker

Several integrity testing methods exist which may be used to evaluate drilled shafts. Each test method has advantages and limitations. On occasion, the results from different test methods may lead to conflicting conclusions, making it difficult to conclusively know which results more accurately represent the quality and integrity of a drilled shaft. This case study focuses on the integrity testing evaluation for two drilled shafts which were constructed using permanent casings and installed through flowing river water. Integrity testing was performed using Thermal Integrity Profiling (TIP) and Crosshole Sonic Logging (CSL) on each shaft. During testing, the influence of flowing water and soil layering needed consideration in the collected TIP data. Similarly, concrete curing time influenced the CSL test results and required the CSL tests to be performed multiple times with additional wait times following concrete placement. To aid in the shaft integrity evaluations, Low Strain Integrity testing via the Pulse Echo Method (PEM) was performed on several shafts and concrete coring was also performed to help further assess the acceptance or rejection of the questionable shafts. This paper presents an overview of the testing methods that were applied, their basic methodology, as well as potential limitations that should be considered when evaluating their results.

Sep 8, 2021

By Jim Bruce

This paper presents details of a slope stabilization scheme built in late 2003 at a 16m-high railway embankment in southern Ontario, Canada. The owner, faced with continuing maintenance and safety issues arising from numerous nuisance slides, and residential neighbors in close proximity to the slope, sought new proposals to replace a previous recommendation to cut down all trees and undertake a deep soil nailing scheme. A non-reticulated micropile array with surface cap beam was proposed and built on the south side of the embankment with no tree removal required. A detailed FLAC analysis was completed, using multiple iterations to arrive at the eventual, optimized micropile depth and spacing. Analysis predicted an 18% increase in the factor of safety. Short term inclinometer monitoring and performance evaluations in the months since construction so far corroborate the prediction.

Jan 1, 2004

By James M. Tantalla, Jr. Ellman

"Construction of the powerhouse for the Willow Island Hydroelectric Project, located at the Willow Island Lock and Dam, required a 120-ft deep temporary excavation inside the limits of a cellular cofferdam on the Ohio River side of the excavation and a soil-bentonite seepage cut-off wall on the landward side of the excavation. Stability analyses were performed for critical sections to evaluate the stability of the soil slopes and rock cuts using limit equilibrium, tension crack, and buckling analysis techniques. The stability analyses indicated adequate factors of safety through the landside embankment sections, and for the weighting berm soil slopes in front of the riverside cellular cofferdam. However, the results of deep-seated stability analyses through the rock supporting the riverside cellular cofferdam indicated marginal factors of safety for the 100-year flood condition. Consequently, the riverside portion of the excavation required enhanced stability measures, namely the installation of long, high-capacity rock anchors. Also, the dewatering system was modified to lower the site piezometric head to near the top of rock to improve the stability of the rock cuts.Thirty high-capacity rock anchors were installed on the upstream, riverside, and downstream sides of the cofferdam rock cut. The rock anchors consisted of multiple, seven-wire strands designed to provide the full-required design load at 60% of the strand capacity. Rock anchor loads varied from 1,968 to 2,074 kips. The maximum number of strands per anchor was 59. Bond lengths assumed an allowable bond stress of 100 psi based on the rock bond from pull-out tests.Project DescriptionAmerican Municipal Power, a nonprofit organization that owns and operates electric generation facilities for its member communities, has been in the process of constructing hydroelectric power plants adjacent to existing navigation locks and dams along the Ohio River. The Willow Island Hydroelectric Plant was recently completed on the West Virginia bank of the river adjacent to the US Army Corp of Engineers (USACE) Willow Island Lock and Dam. The plant is on the opposite river bank to the locks, and includes two turbine generating units with FERC rated capacity of 44MW at a 20-foot head differential. The Ruhlin Company of Sharon Center, Ohio was awarded contracts to construct both the cofferdam and the powerhouse. Construction began in mid-2011, and was completed in early 2016."

Jan 1, 2016

By Peter J. Jancich

This paper describes the installation of high capacity Augered Pressure Grouted piles which support structural loading from a four level parking garage in west-central DuPage County, Illinois. The subject site is characterized by a variable glacial geology which presented, to the designer, a number of problems with respect to analysis and prediction of pile capacities, and, to the contractor, the very real difficulties associated with estimating the costs of, and installing foundation units in highly variable subsurface conditions. 2. General Site and Subsurface Conditions 2.1 Site Conditions - The subject site is part of an overall 300 acre property. Topographically, the overall site is saddle shaped with higher elevations along north and south boundaries and a subdued, east-west trending swale centrally located. Elevation relief is on the order of 25-30 feet (7.6-9.2m).

Jan 1, 1991

By George J. Tamaro

The design and construction of foundations in the New York City area are usually dictated by the widely varying geologic conditions encountered in the five boroughs, particularly along the spine of Manhattan Island. Rock extends well above sea level at the northern reaches and falls to depths in excess of 250 m at the barrier islands at the southern extremities. These highly variable geologic conditions, significantly affected by glacial activity, dictate different design and construction approaches throughout the five boroughs of New York City. Extensive rock removal is required at the north while long piling is dictated in the south. Similar changes can occur within a project site on Manhattan Island. This paper will describe these conditions in general, will identify the various solutions used to solve these problems and will summarize various foundation types used in the New York City area.

Jan 1, 2000

By Allen Cadden

The type of soil we had was a silty fine sand. It had been placed by hydraulic methods in 1904 so it was quite clean I would say less than 10% silt the rest of it was very loose sand. That I'm not certain, I've only done it on sandy soils but it would stand to reason that some sort of a number should apply because you are measuring the amount of work that you are doing to it so if the soil is fairly consistent over the site it should be able to generalize from there but I don't know for a fact that it works. Well, verifying to ourselves that this method actually worked because we weren't certain at first when we were doing it so then we would develop the numbers and then check the results.

Feb 10, 2003

By Benjamin Jennings, Jason Herron

In the summer of 2016 Xcel Energy experienced a storm event that resulted in the collapse of approximately 8.5 miles of a 345 KV transmission line near Rogers, Minnesota. In design of the new transmission line, Xcel Energy determined that ten tower locations would be replaced with steel H-frame structures supported by helical piles instead of wood H-frame structures supported by driven wooden piles. A steel foundation was proposed for the towers due to time constraints and site conditions unfavorable to large pile driving equipment. Xcel Energy contacted the helical pile manufacturer Hubbell Power Systems, Inc. (HPS) for aid in the design of a complete steel foundation for the structure legs. With the shear, moment, and axial loads provided, the manufacturer used pile group modeling and axial capacity software to design a four helical pile group; and used 3D modeling and finite element software to design a moment resistant grillage to connect to the tower base. The steel grillage utilizes a new moment resistant connection and clamp system to transfer loads from the piles to the grillage. This connection provides a true fixed head condition and reduces lateral deflection issues typical to smaller diameter piles in pinned head connections. The clamp is designed to deform the helical pipe pile shaft and transfer the full axial load of the structure through the mechanical and friction connection. The helical piles and the moment resistant grillage were manufactured with shorter than average lead times and a helical pile installation contractor performed the installation. An expedient plan of install was developed by the contractor that resulted in an average installation rate of one complete set of tower foundations per day. The design of the moment resistant grillage, clamping system, and excellent foundation construction by the contractor provided an expedient and efficient foundation system to be discussed in this paper.

Jan 1, 2017

By Travis A. Shoemaker, Mitchell S. Youmans, Nancy T. Chin, Michael S. Senior

A geologic assessment and stability analysis of the right abutment of Boundary Hydroelectric Dam in Pend Oreille County, Washington was completed in May 2017. The stability analyses identified a potential failure plane of a rock block that supports a bridge abutment, and weight restrictions were established to reduce the bridge loads. To restore full use of the bridge, a long-term stabilization solution was designed. A two-phased construction approach was implemented to reduce risk: (1) cable lashing and wire mesh and (2) 24 permanent post-tensioned tiebacks. The tiebacks were located and sequenced based on stabilization effect and site access to incrementally ease the bridge loading restrictions throughout construction. Due to weight restrictions and site tolerances, all work was performed with rope access construction methods. The contractor’s means and methods, tight drilling tolerances, and an exploratory adit within the rock block made the construction uniquely challenging. Due to limited exploratory data and irregular rock face geometries, the design orientation, location, and tolerances of the tiebacks were established in a 3D Building Information Model (BIM). The 3D model was revised frequently during construction to 1) model the as-drilled conditions of the tiebacks; 2) compare with the remaining proposed anchors; 3) anticipate the contractor’s sequence to reduce risk during drilling; 4) accommodate the contractor’s requests for information; 5) make design changes based on field observations; and 6) incrementally assess rock block stability. The 3D model was created using BIM software and automated using custom programming to link per-plan, proposed, and as-installed tiebacks between the 3D model, field logs, and a stability analysis. This system allowed for a near real-time 3D model and stability analysis, which were easily communicated between the design team and field staff. This workflow and automated model nearly eliminated manual editing of the 3D model, accelerated contract document response time, and helped reduce risk for the owner, contractor, and engineer. Here, we present a successful case study utilizing the Observation Method and a real-time 3D model to complete a project with numerous complexities relating to design, communication, and risk.

By Kalyani Devabhaktuni, Mike Minton, Mark T. Howe, Yan Zhang

During the procurement phase of a Design-Build (DB) project, design-build contractors must often commit to a fixed price based on limited or incomplete geotechnical information. This lack of information can result in an inaccurate assessment and allocation of project risk to either the contracting authority or the DB contractor. This paper presents a case study of an elevated water tank supported by mixed ground improvement techniques, including Vibro-Compaction (VC), Aggregate Piers (AP) and Compaction Grouting (CG) in East St. Louis, Illinois. An adaptive design and contracting approach provided the best value solution for a complicated set of geotechnical problems, including static bearing capacity and settlement concerns as well as liquefaction induced settlement. Close cooperation between the owner, the tank contractor, the geotechnical engineer and the ground improvement contractor was essential to produce an effective solution. Ground Improvement techniques resolved the geotechnical challenges at the site through adaptive design methods, utilizing progressive rounds of verification and real time data acquisition to achieve performance objectives. This paper details the evaluation of geotechnical criteria, the selection of ground improvement techniques, the adaptive design and implementation of ground improvements, as well as contracting methodologies used to ensure that the best value was provided. PROJECT INFORMATION In November, 2016, CB&I Storage Tank Solutions (McDermott) submitted a design/build proposal for an elevated water tank for Illinois American Water Company (IAW) in East St. Louis, Illinois. The purpose of this tank was to have backup water capacity for power generation. In the RFP, IAW requested two alternate styles of tank: Option 1, a 1250 Million Gallon (MG) Composite Elevated Tank or Option 2, a 1250 MG Waterspheroid tank. Option 1 consisted of a steel tank supported on a concrete tower. Option 2 consisted of a steel tank supported on a steel shaft. The height (determined by IAW) was 140 feet to the top capacity line measured from top of floor slab.

Jan 1, 2019

By Jamey Rosen, Georgette Hlepas

"Bluestone Dam is a concrete gravity structure with an overall length of 2,060 feet and a maximum height of 165 feet above the streambed. Several major project modification designs have been implemented and additional modifications are currently in construction and design phases. Due to the various modifications since original construction was completed in 1948, detailed documentation with visualization of the project features is needed. A three-dimensional model of the internal and external features of Bluestone Dam was generated from LiDAR data, survey information, and other data sources. One of the key features of interest in this model is an accurate visualization of over 200 dam anchors based on downhole anchor surveys. The model is accessible in Microstation and Geographic Information Systems (GIS), allowing users to rotate the anchors in three dimensions; view them in the context of geology, internal dam structural features, historical construction records, site photographs, bathymetric data, and instrumentation data. Users can “click” on individual anchors to view associated construction details and open a comprehensive installation packages. The model will be used by the United States Army Corps of Engineers (USACE) as part of a larger Geospatial Data Management System as a historical accounting of the project construction data, and be a long-term living document for use by both design engineers and operations staff to assess dam safety risk and to design future project modifications.IntroductionDuring the life of any project, critical data concerning the construction and performance history are required to be collected and maintained. The data collected prior, during, and post-project construction help with the design process, ensure that the project is built to specifications and is performing as per design intent. During the Post-Implementation Evaluation (an evaluation performed after a major project modification), these data are used to visualize the repairs, verify the construction was performed per design intent, and document the history of the construction phases, associated test results, and overall effect on the project. The project described in this paper is the construction of a system of tools to effectively use these data.Data collected and maintained during the operations phase helps to ensure that the project is continuing to perform as per design and aids in advance warning of any potential failure or required maintenance. Dam Safety, Emergency Management (EM), and Operations and Maintenance personnel can use the system to verify the status of the project in preparation for a high flood event. For example, if there is repair work being performed on a critical feature of the project that would affect the operation of the dam structure during a flood event, Operations personnel would be responsible to update the status of the system such that Dam Safety and EM would be able to identify the feature that is out of service, its date of expected repair completion, and the implications during a flood. In addition, risk assessments typically require a full history of the project and its performance. Any concerns that arise concerning the safety or performance of a project will require a full documented history of the project and its components. Proper documentation and data management are key in this assessment process."

Jan 1, 2016

By Clifford Taylor, Alexander Zöhrer

"The execution of deep basement excavations under narrow conditions is one of the most challenging tasks in geotechnics. The vicinity of neighbouring buildings, roads, and underground structures such as sewers or power lines, quite often prohibits the application of standard solutions. In addition, legal considerations in the use of adjacent properties is becoming increasingly difficult. This paper will present some innovative approaches to overcome the above-mentioned challenges based on several case studies from central Europe. For every project the design approach as well as the techniques used for execution will be explained, detailing both the advantages and the limitations of the applications. One case study shows a deep basement excavation (approx. 17m) in the centre of Prague, Czech Republic. This project featured many challenging boundary conditions (narrow construction area, high ground water table, jet grouting column embedment into bedrock, constraints regarding use of ground anchors due to property rights, etc). The realisation of the complex design is described and illustrated in detail. Other case studies will show the combined application of bored piles with jet grouting and also explain the design of vertical prestressed anchors for retaining walls.INTRODUCTIONThe development of urban areas has always presented challenges, from access for equipment and materials to the rectification of existing foundations in unknown condition. Compounding these is the increasingly stringent requirements to retain, maintain and reduce impact on culturally and historically significant structures. As available space is becoming more limited, optimisation of real estate has resulted in buildings getting higher and their basements deeper below ground. Two or more basement levels are quite common, with typical excavation depths ranging from 5 to more than 10m. Additionally, we are faced with neighbouring buildings that are equally high, deep and massive. These buildings directly adjacent the retaining structure require underpinning to limit settlement, and in cases where they are within just a few meters, this building mass generates additional earth pressure for the retaining wall to support, resulting in complex loading cases.This paper highlights several common challenges and explores the measures implemented to overcome them. The challenges and examples of either design based solutions or practical applications will focus on the following topics – the limitations of conventional geotechnical construction methods, overcoming challenging geology and the requirement for watertight basement constructions."

Jan 1, 1900

By Donald A. Bruce

"The Deep Mixing Methods (DMM), in their current forms, have been employed in the United States since 1986, although an earlier version had seen service from 1954. The earlier developments were strongly influenced by practices in the Nordic countries and Japan, while by the late 1980’s several DMM systems had been developed in the U.S. itself. Since then, DMM has continued its evolution, principally via the challenges of a series of large, landmark projects, but also via distinct, significant technological advances. This paper highlights the key points in the history of DMM in the U.S., and provides an overview of the different methods currently in use.IN THE BEGINNINGIt is a common misconception that the history of applications of the Deep Mixing Methods (DMM) in the United States dates from 1986 when SMW Seiko Inc. — a subsidiary of Japan’s Seiko Kogyo Company — was established in the Bay Area. However, the author believes that Intrusion Prepakt Co.’s patented MIP (Mixed in Place) system had been used, albeit sporadically (about 30 projects are recorded), since 1954 (FHWA 2000, 2001). Ironically, by 1961 this single auger method had been extensively used under license in Japan for excavation support and groundwater control — by the Seiko Kogyo Company. By 1972, the original MIP technique had been succeeded by more advanced Japanese methods, involving multiple augers. Intrusion Prepakt have long since become defunct.The first systematic studies of contemporary Deep Mixing Methods in Japan began in 1967 when the Port and Harbor Research Institute of the Ministry of Transportation began laboratory testing using granular and powdered lime for treating soft marine soils. Fundamental studies continued through the early 1970’s, by which time the development of industrial scale equipment was well advanced, having its first application on a marine trial near Haneda Airport. Coincidentally, laboratory and field research also began in 1967 in Sweden (“Swedish Lime Column Method”) for treating soft clays using unslaked lime. Reportedly the progenitor was a Norwegian, Kjeld Paus, who had made observations on fluid lime columns in the U.S. It would seem that developments in Japan and the Nordic countries proceeded independently until 1975 when the technology leaders from each group (Broms and Boman; and Okumura and Terashi, respectively) presented their — very similar — findings at a conference in Bangalore, India. Limited technical exchanges ensued thereafter.Whereas the Nordic developments continued to focus on the use of dry reagents (cement and lime) and relatively light equipment compatible with operating on and in very soft clays and organics, the Japanese progressed into the use of fluid reagents (cement-based grouts) and heavier equipment for both marine and land-based projects. Thus, by 1986, there were a large number of proprietary (wet and dry) DMM systems in Japan, and a rapidly growing market already by then accounting for over 12,000,000 m3 of ground treatment."

Jan 1, 2015

By Christophe H. Locussol

D.C. United, the professional soccer team located in Washington, D.C., completed a 20,000 seat capacity stadium in July 2018 named Audi Field. The project initially considered a foundation system consisting of roughly 800 prestressed concrete driven piles configured in groups with pile caps. A value engineering alternative proposed in a design-build manner ultimately resulted in the use of 300 single element Auger Cast Piles (ACPs) for the foundation system. The ACPs ranged between 1.5 ft and 4 ft in diameter, were up to 85 ft in length, and were connected through a system of grade beams to accommodate large lateral induced loads. Limitations in conventional analytical methods were encountered during the structural design of the piles due to the complexity of the lateral loading and pile fixity conditions. An innovative approach using advanced finite element modeling that incorporated the framing effects of the grade beams was required to meet the strict movement criteria despite large lateral loads.

By James P. Chivilo, Gregory R. Meeder, Scott J. DiFiore, Matthew H. Johnson

New construction in metropolitan areas has direct impacts on immediate neighbors and abutters. While noise and dust are generally nuisance concerns, demolition, vibrations, excavation, and dewatering can cause structural damage to adjacent structures. Different cities, states, or jurisdictions have different regulations that dictate requirements, roles, or responsibilities for varying parties during construction. The authors will introduce and discuss risks of new construction adjacent to existing structures, and the legal framework in Illinois which requires the owner of the new construction project to provide adequate protections for adjacent existing structures. The authors, who are engineers and attorneys, will discuss technical and legal concerns, and will highlight the importance of early and frequent communication among project participants to manage risks, despite whether or not any local regulations exist to drive the process. RISKS IN ADJACENT CONSTRUCTION New construction in metropolitan areas inherently involves some combination of noise, dust, ground-borne vibrations, earth excavation, and subgrade dewatering. These issues have potential to directly and adversely affect abutters and their property. Noise and dust can be nuisance concerns, while vibrations, excavation, and dewatering can result in damage to abutters’ structures. Noise and dust are unlikely to lead to physical damage to abutters’ property, and can be controlled with limited work hours and good housekeeping practices. Vibrations and excavations, however, if not well understood, planned for, and mitigated, can result in serious damage to abutters’ structures. In turn, this damage introduces additional and often significant costs and schedule delays.

Jan 1, 2019

By Barritt Lovelace

Collins Engineers has been researching and implementing the use of drones on Civil Engineering Projects since 2015. Applications include bridge inspection, asset management, mapping, construction site management and emergency response. Recently this technology was used to map and model construction sites with deep foundations to verify and quantify designs. The ability to collect and use large amounts of data is transforming our world. Drone hardware and software is being used to capture and digitally replicate assets, giving owners unprecedented ability to visualize and manage their projects. Our teams help owners collect and process drone data into deliverables to be analyzed, annotated, stored, and shared. The use of drones can transform the way projects are managed and can improve project workflows. Data collected with drones can be processed into a digital twin of any project site or asset. This digital twin provides owners with a three-dimensional geometrically and geospatially accurate model. These models can be annotated and tagged with information that can be stored and shared locally or on cloud-based platforms. The data can be exported and used in a wide variety of CAD and GIS platforms. Goals When considering the use of UAS for several items need to be considered when establishing project goals. Safety Drones can be used to reduce job site safety risks in two ways. The first is that use of the drone can remove personnel from harm’s way. Surveyors and other project staff will traditionally walk the site to collect survey and other site information. These efforts can be replaced with the use of a drone eliminating much of the need for personnel to be on the job site itself which improves safety. The other way safety can be improved is that a digital model of a job site can be created on a daily or weekly basis that can be quickly analyzed for safety hazards. This analysis could be done remotely by safety officers to identify job site hazards which can then be corrected before injuries happen. Improved Deliverables Perhaps the most important reason to incorporate drones into project workflows it the ability to improve the project deliverables. Drones have the ability to quickly collect large amounts of high quality data which can be processed into orthomosaics, point clouds and 3D models that give engineers and project managers the information they need to make better decisions on design or project management.

Jan 1, 2019

By Vladimir M. Korolev

The field studies conducted at the experimental-production sites allowed to develop the technology of arranging drilling piles in loess subsiding grounds over 25 m deep and over 250 mm in diameter, to select optimal compositions of flush fluids, to assess the carrying capacity and field of use of the piles under test and to produce a special equipment. The dependence of the ultimate axial pressing-in load on pile driving into the non-subsiding section, its diameter and method of fulfillment, as well as the ground moisture dependence of the specific ground resistance along the piles' side surface within the limits of the subsiding section were determined. The study results allowed to reduce the length of the work piles and the number of bars in the reinforcement frames. The obtained experimental data enable to give a preliminary assessment of the piles' carrying capacity under complicated engineering-geological conditions of subsiding grounds.

Jan 1, 2002