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Over the last few years, students taking the Introduction to Geotechnical Engineering course at Tufts University have performed term projects where they develop written reports and oral presentations on various topics in geo-engineering. This paper presents how these efforts have enhanced the learning experience of the course. Specifically, the paper presents how the project is integrated into the course, assessment methods used for grading, and the value such projects have had on student learning, based on post-course evaluations. A shortened example of a student’s work is presented. It can be concluded that the project allows not only a deeper appreciation of geo-engineering by the students, but also provides an avenue for students to practice their communication skills; one of the ABET Criterion 3 outcomes.

A complex cleanup project that included dredging and capping of contaminated sediment, construction of two breakwaters, habitat enhancement, upgrade of a seasonal small craft facility and installation of new aids to navigation was completed by the Port of Anacortes, Washington in collaboration with the Department of Ecology, Washington and potentially responsible parties (PRP). The complexity of project site physical processes, extent of dredging, and strict regulatory requirements on the clean-up action necessitated an innovative engineering approach to all above elements of the project. The approach also included application of the most advanced coastal engineering modeling tools including wave, tidal flow, sediment transport and stability, and coastal geomorphology hydrodynamic simulators. Based on analysis of the numerical modeling results, optimal engineering decisions were made for design and construction of detached breakwaters, dredging and removing a portion of the contaminated sediment, capping of the remaining contaminated sediment, and removing the old deteriorating creosoted sheetpile wall breakwater. Also, the results of the study determined the possibility of creating a sheltered eelgrass habitat and year-round small craft facility for different types of activities such as fishing, kayaking, and sailing.

The FEMA P695 Methodology, developed through the recent ATC-63 Project, incorporates ground motion guidelines that include a so-called Spectral Shape Factor (SSF). This SSF adjusts the predicted collapse capacity of the building to account for the spectral shape of ground motions. This paper explains how aspects of this new FEMA P695 Methodology could be adapted for use in refining the target displacement equation (i.e. inelastic displacement demand) in the ASCE/SEI 41 Nonlinear Static Method to account for spectral shape. The final result would be an additional coefficient (termed the “spectral shape coefficient”) that would reduce the target displacement for sites where the ground motion is expected to have a less damaging spectral shape. This paper outlines how one would compute this spectral shape coefficient for any site and building of interest, and then explains the additional work needed to implement this new coefficient into ASCE/SEI 41. An example is provided to illustrate the effect that the new coefficient has on the computed target displacement. For a 2% in 50 year motion at a San Francisco California site, application of the spectral shape coefficient results in a 40% reduction in the target displacement.

Tunnel and large cut-and-cover structure response to earthquakes is dominated by the surrounding ground, and, contrary to shallow-founded structures, does not depend on the inertial properties of the structures themselves. The focus of the underground design is on the free-field deformation of the ground and its interaction with the structure, i.e., a soil-structure interaction phenomenon. This paper summarizes the performance in recent past seismic events of deep, large underground structures, and then elaborates on their design approach: geotechnical, seismic criteria and structural factors. Analytical models are examined and conclusions drawn about their advantages and limitations. A general approach to the design of deep underground structures is illustrated through the on-going design of a particular project.

The Port of Anacortes, Washington is working on implementation of a complex clean-up project that includes excavation and dredging of contaminated sediment, capping the remaining sediment, constructing the detached attenuator, removing the old Port breakwater, and constructing a habitat and a pier for recreational activities. The complexity of the clean-up project is exacerbated by intense wave action and ongoing shoreline and bottom slope erosion. In order to determine a technically feasible and environmentally acceptable engineering solution for the clean-up project, the Port completed a comprehensive coastal engineering study that included extensive numerical modeling to evaluate wave action, tidal flow, and sediment stability. Based on results of the study, an optimal solution was found; preliminary and final engineering were completed; and environmental clearances were obtained. Project construction started in July 2009 and is scheduled for completion in March 2010. Copyright 2010 ASCE.

Waste paper sludge, or fiber-clay as it is often identified when used as a resource for recycling and reuse in new applications, has over the last several years become a vital component in several geotechnical uses and a variety of manufactured products. Among the major reuses of fiber-clay has been its use as a cover material for sanitary landfills, after thorough laboratory and field evaluations. Because of the high kaolin clay content in the manufacturing of paper products, there is a high residual of clay in waste paper sludge from the manufacturer's waste water treatment plants. The reuse of cover material has resulted in a cost avoidance for the waste generator, reducing or eliminating disposal costs as well as eliminating the need for finding a disposal site. There are also cost savings for landfill operator and owners who otherwise would have to secure an adequate clay source. When compacted, most fiber-clays exhibit adequate hydraulic conductivity and shear strength for use in landfill covers. In addition to its use as a cover material, the fiber-clay, when combined with a pozzalonic material such as fly ash and aggregate, has been used as one of the major components for road beds, both as subsurface base and as a finished surface for remote access and secondary roads. Additional uses include the manufacturing of kitty litter and animal bedding. This paper will review the history and technology involved in evaluating the potential uses of fiber-clay. Extensive laboratory and field testing has been done to determine its shear strength, slope stability, hydraulic conductivity, and settlement potential. Information is presented on the various testing techniques and results, together with examples of actual field projects.

Despite a great deal of interest in risk management of dams and water resource facilities during the latter part of the 20 th century, few opportunities to apply these emerging concepts arose in practice. This paper examines the fundamental principles of risk assessment and decisions concerning their management can not be carried out in the traditional way decisions concerning the safety of dams were made in the past. A framework for managing the risks posed by dams is presented as is a proposed approach to determining when risk assessment is appropriate, and the professional and societal structures and institutions that are required to permit implementation of risk assessment in dam risk management.

Widely varying material properties and joint configurations of the different pipe materials in common use have made it difficult to develop a coordinated thrust restraint design practice. This has resulted not only in significantly different guidance from AWWA design manuals for different pipe materials and agency requirements, but also widely varying design practices and company specific best practice approaches within the engineering community. Recognizing the need to develop consensus among practicing engineers as well as industry representatives and experts; in 2008, the members of the American Society of Civil Engineers (ASCE) Technical Committee on Pipeline Installation and Location formed a special task committee "Thrust Restraint Design of Buried Pipelines". The objectives of this task committee were: 1) To document current design practices of thrust restraint systems for various pipe materials; and compare current practices with theory. 2) To document the historical evolutions of the different design approaches, collect and compile field tests completed for different pipe materials. 3) To explore improvements to current practice, develop consensus, and propose recommendations for the development of a manual of practice. Since 2008, the task committee has prepared a white paper documenting the above objectives, held a workshop on thrust restraint design at the 2010 ASCE Pipelines Conference, and begun preparing a manual of practice (MOP) with the aim of improving and consolidating current practice into a more cohesive, if not universal approach. The task committee has also presented several papers at the last three ASCE Pipelines Conferences, documenting findings and progress. This paper briefly summarizes the progress by the committee since its inception in 2008, focusing on the progress made by the committee since the 2011 Pipelines Conference. It includes updates on the progress toward developing an analytical model for thrust restraint that is intended to form the backbone of the MOP. The analytical model will include factors that deal with: pipe-soil interaction including frictional and lateral resistance, pipe and joint flexibility, movement required to develop soil resistance and the limitations of joint materials, type and geometry on movement induced by thrust forces. Both thrust block and restrained joint methods are included. A simplified approach for common applications is also proposed.

This paper suggests a new theoretical lens to understand and manage construction design processes that draws on Heidegger’s theory of deliberate action (Heidegger 1963). The lens interprets the day to day activities of designers as being immersed in practice without deliberate attention to everyday actions. Being immersed, designers do not reiterate the initial problem context and will only design for initially dened criteria. Only if the day to day ow of immersed practice is interrupted or is breaking down designers will involve in what Heidegger calls \involved thematic deliberation" or \theoretical detached deliberation" (Sandberg and Tsoukas 2011) that allows them to reiterate the initial problem context. This early position paper, introduces this new theoretical lens and shows its value by analyzing a number of design episodes that I observed during my ongoing ethnographic research work with designers. The examples show that the new lens allows for a good understanding of the increasing problems of designers to identify the wide range of societal and engineering issues during post-modern construction design eorts upfront. I posit that this better understanding, in turn, will support the better management of the changing problem contexts that occur on almost all post-modern construction design projects.

There are four major types of macro-evaluation on traffic safety traditionally adopted in China and overseas. However, as the number of influential factors of traffic safety increases, these evaluation methods are becoming less capable in practice. The introduction of Fuzzy Theory provides a new approach to this problem. This paper based on the traffic accident data of Shanghai and Suzhou has established a macro-evaluation model for assessing the safety performance of mixed transport modes, which include cars, motorcycles, gas motorcycles (LPG), electric bicycles and traditional bicycles. The model indicates that the safety performances of LPG, electric bicycles and traditional bicycles are much higher than that of cars and motorcycles. Electric bicycles and traditional bicycles have similar safety performances in the two cities. These findings set up a reference for the establisher of urban transport policies.

This short paper presents revised information on the creep reduction factors used in the widely accepted method for geotextile mass per unit area design to prevent geomembrane puncture. The laboratory tests have been ongoing for 6-years and have not failed to date, leading to the tentative conclusion that published values of RF CR are quite conservative.

This study uses lime and class C fly ash, an industrial byproduct of electric power production produced from burning lignite and subbituminous coal, to study the plasticity reduction in highly expensive natural clays from Idabel, Oklahoma. This study is important, especially in Oklahoma, because most of the native soils are expansive and cause seasonal damage to roadways and structures. The addition of lime or fly ash helps to arrest the shrinkage and swelling behavior of soil. Four soil samples with the same AASHTO classification were used in this study to show shrinkage variability within a soil group with the addition of lime and class C fly ash. The plasticity reduction in this study was quantified using the linear shrinkage test. It was found that soils classified within the same AASHTO group had varying shrinkage characteristics. It was also found that both lime and fly ash reduced the lienar shrinkage, however, the addition of lime reduced the linear shrinkage to a greater degree than the same percentage of class C fly ash. Even though it takes much less lime than fly ash to reduce the plasticity of a highly expansive soil, it may be less expensive to utilize fly ash, whichmore » is a waste product of electric power production. Lime also has a lower unit weight than fly ash so weight percentage results may be misleading.« less

[EN] Temporary shoring structures are used in the construction of reinforced concrete buildings to transmit the loads of newly poured slabs onto the lower floors. The main problems involved in the use of shores/props are: a) the possibility of having higher loads than those initially foreseen, and b) the structural efficiency and cost of the system, which is normally over-sized due to being designed to bear the maximum load of the most demanding building operation. This paper describes a test carried out on a full-scale one-story building to analyze the behaviour of load limiters (LLs) installed on shores under actual construction loading conditions. The theoretical approach and development of this new LL concept were described in previous papers. As these LLs still had not been tested in actual buildings, this paper covers the existing need for a test in the form of a "proof of concept". It also includes computer simulations and recommendations for the use of LLs., The authors would like to express their gratitude to the Spanish Ministry of Education, Culture and Sport for funding received under the FPU Program [FPU13/02466], to the Generalitat Valenciana [GV/2015/063] and also to the Levantina, Ingenieria y Construcción S.L. and Encofrados J. Alsina S.A. business companies for their invaluable cooperation.

ADAS (Automatic Data Acquisition Systems) are electronic devices used to automatically read, store and transmit measurements from geotechnical, environmental and structural sensors used for monitoring dams and levees. Because of the specificity of the conditions of their deployment in outdoor, spread-out and sometimes harsh conditions, ADAS used for those applications need to have a number of features and functionalities which are discussed in the paper. The paper will be limited to ADAS for monitoring static measurements, as opposed to systems for dynamic measurements such as accelerations due to earthquakes. Low power consumption, robustness, modularity, ease of deployment, diversified network configurations between units such as line , star and tree networks, a wide variety of telemetry options such as radio and cell modems are all features that are essential for a successful deployment in the field. The paper covers the features that are nowadays mainstream on available solutions for ADAS for dams and levee monitoring, including discussions on network configurations, power supply options, network access options and real-time monitoring. The advent of low-power low-cost radios that open the possibility of eliminating all surface cable runs on dams and levees is also discussed.

Sensitivity analysis involving different random variables and potential failure modes of cantilever sheet pile walls for different soil conditions focuses on the fact that, high sensitivity of a particular variable on a particular failure mode does not necessarily imply a remarkable contribution to overall failure probability (Pf). The present paper aims at identifying a probabilistic risk factor (Rf) for each random variable based on the combined effects of Pf of each mode of failure and sensitivity of each random variable on these failure modes. Three different soil conditions are considered: (1) cohesionless soil above and below dredge line, (2) cohesionless soil above dredge line and cohesive soil below dredge line and (3) cohesive soil above and below dredge line. It is observed that friction angle of both foundation and backfill soils are the major guiding factors for Case 1, while for Cases 2 and 3, cohesion for foundation soil dominates over the other two random variables. Thus the present paper proposes a safe and economic design by assigning different Rf for different random variables for sheet pile walls embedded in different subsurface conditions and varying positions of water table.

When estimating the time-rate of settlement for foundation soils treated with vertical drains, understanding the horizontal drainage behavior of the soil is important because the time of consolidation settlement may be critical to the overall construction schedule and sequencing. This paper explains the process for obtaining the horizontal properties of soft soils in the laboratory using a Rowe cell, a laboratory device that directly measures the horizontal drainage of soft soil samples through a radial consolidation test. The Rowe cell further allows for back-saturation of test specimens and the ability to replicate in situ lateral stress conditions with an applied cell pressure. This paper summarizes how challenges associated with specimen preparation, test setup and procedure, and data analysis and interpretation can be overcome. Finally, this paper demonstrates that this is a viable method that should be considered more often for obtaining horizontal drainage design parameters.

Ground-source heating of bridge decks can be an alternative to the use of salts and chemicals to deice bridge decks. Energy foundations, geothermal boreholes, shallow trenches, or the approach embankment can be utilized as energy storage media and heat exchange pathways to utilize the ground as a heat source. Coupling the energy foundation with a ground-source heat pump can provide higher inlet fluid temperatures and result in more effective bridge heating but at the expense of greater energy consumption and increased system complication. Circulating the fluid directly from the energy foundation to the bridge deck relies heavily on the in situ ground temperatures. This paper outlines the operational principles and how these are related to the design parameters of bridge-deck deicing systems. A series of parametric analyses was performed to investigate the bridge-deck heating process. The analyses considered a variety of tube spacings, inlet fluid temperatures (i.e., ground temperatures), flow rates, wind speeds, ambient temperatures, and thicknesses of concrete cover over the circulation tubes. The results serve as a benchmark to gauge the operational conditions and the energy requirements for designing ground-source bridge deck deicing systems. Ground temperatures serve as a baseline for heating of bridge decks with passive heating in the winter, and this study underlines its limitations at colder environments. This can be overcome by collecting heat from the bridge deck in the summer and injecting the collected heat into the ground to raise the ground temperatures. This stored energy can be reclaimed in the winter when needed. The issues related to heat collection and ground storage are part of a broader study and fall outside the scope of this paper.

This paper discusses the practical aspects of preparing Geotechnical Baseline Reports. Guidelines for the preparation of Geotechnical Baseline Reports were established in the ASCE publication entitled, “Geotechnical Baseline Reports for Construction,” dated 2007. However, the practical aspects of actually writing a Geotechnical Baseline Report and the risk assumptions associated with this document are highly controversial. Not every project needs a Geotechnical Baseline Report and not every geotechnical engineer is equipped to write one. This paper will provide its own set of guidelines for the preparation of Geotechnical Baseline Reports. The paper suggests that Geotechnical Baseline Reports are one contractual format for handling such as third party impacts and differing site conditions that often arise when involved with subsurface construction.

This paper describes a study of the behavior of a group of piles under impact loading. Many structures such as bridge piers, offshore platforms, or berthing foundations can be subjected to the horizontal impacts from ships during their lifetime in which the system failure would have serious consequences. Guardrails for road side safety are another type of impact-resisting system that are extensively used and have a direct relation to human life and cost. Moreover groups of piles can serve as an efficient and relatively cost-effective protective structure around critical and important facilities. Prediction of the system response during the impact can lead to a more effective and economical design. There has been a very limited amount of experimental work on lateral response of group piles under impact loading in particular in the field of full-scale tests. This paper describes a full-scale field test performed on a group of eight side-by-side piles embedded 3 m in a loose sand to sustain an impact of a 6800 kg truck with an approaching velocity of 80 km/h. The instrumentation includes accelerometers on the truck, strain gauges on the posts, and high-speed cameras to capture the deflection. The eight posts and the connector beam have been simulated using an advanced numerical simulation software LS-DYNA (Livermore Software Technology Corporation) to characterize the features of the soil-pile-beam interaction under impact and improve the design methodology.

Bridge scour is a major cause of damage to bridge foundations and abutments. Approximately 17,000 scour-critical bridges exist in the United States. Scour-critical bridges are bridges with foundations that are unstable for calculated and/or observed scour conditions. This designation comes in part from the use of overconservative methods that predict excessive scour depths in erosion-resistant materials. Other available methods capable of overcoming this overconservatism are relatively uneconomical because they require site-specific erosion testing. This paper presents the assessment of two bridge case histories using the observation method for scour (OMS). OMS is a relatively new quantitative bridge-scour assessment method that accounts for time-dependent scour depth using field measurements. This method, which does not require site-specific erosion testing, was developed as a first-order assessment method for use in combination with routine bridge inspections. OMS uses charts that extrapolate or interpolate measured scour depths at the bridge to obtain the scour depth corresponding to a specified future flood event. The vulnerability of the bridge to scour depends on the comparison between the predicted and allowable (threshold) scour depths. The case histories presented in this paper consist of two Texas bridges, one designated as scour critical and the other as stable by the Texas Department of Transportation (TxDOT). Both stable and scour-critical bridges were selected to test OMS and also compare it with TxDOT's scour designation. These case histories serve to demonstrate the validity and applicability of OMS to full-scale bridges and to provide practitioners with two potentially useful real-life case histories that could serve as examples for engineering practice. A validation process was performed on the two case histories using historical scour measurements and flow data. The validation exercise showed that there was good agreement between predicted scour depths using OMS and field measurements. OMS was then applied as a bridge-scour assessment tool to both bridges using the 100-year flood as the future flood and the outcome of OMS compared with the original TxDOT designation. As a result of this, the originally scour-critical bridge was found to be stable according to OMS. The bridge originally designated as stable was also found to be stable according to OMS.

In February of 2011 an earthquake event caused significant damage and loss of life in Christchurch, New Zealand. Such an event serves as motivation for improved foundation design and characterization of the shallow subsurface. In January of 2013, University of Texas engineers acquired surface wave data which has been made available to the ASCE GeoInstitute Geophysical Engineering Committee for a benchmark project. Participants were invited to process and interpret the common data set. This paper reports the results designated as those of “Analyst A”. The active vibroseis and sledgehammer data were combined to produce a composite Rayleigh wave dispersion curve. Alternative soil profile representations were considered. The resulting image is of low velocity zone sandwiched between a faster surface zone and a faster profile down to 30 meters depth. INTRODUCTION The UTexas1 SurfaceWave Dataset was acquired in Christchurch, New Zealand. The site was located approximately 1.5 km from the coast. The Geophysical Engineering Committee of the ASCE GeoInstitute has organized a benchmark project in which participating geophysical engineers have been invited to process and interpret this common data set with tools of their own choosing. The instructions were to work as much or as little of the data as each participant desired. The available data include both active-source and ambient noise sets. This participant has chosen to only work the active-source data. The vibrator data were processed in the frequency domain, the hammer data in the time domain. The resulting dispersion curves were then combined to provide a composite dispersion curve. Inversion of the composite dispersion curve was done employing a 1-D-gradational soil profile in which the objects of the inversion are control points whose depth and shear-wave velocity assignment may vary. The reader is referred to Michaels (2011) for another example of this representation. page 1 This is an author-produced, peer-reviewed version of this article. The final, definitive version of this document can be found online at Geo-Congress 2014: Technical Papers and Keynote Lectures, published by the American Society of Civil Engineers. Copyright restrictions may apply. doi: 10.1061/9780784413272.074

Over the past few years, intelligent compaction (IC) has been a focus of research, demonstration projects, and specification development in the United States. The Federal Highway Administration (FHWA) has recently moved IC to national level implementation. Equipment manufacturers, individual state departments of transportation (DOTs), and the Technology Transfer for Intelligent Compaction Consortium (TTICC), a Transportation Pooled Fund, TPF-5(233) initiative, are also focusing on implementation efforts. What this paper does is describe the results of a series of workshops attended by more than 400 attendees—representing several state DOTs, FHWA, equipment manufacturers, and researchers—that contributed to a detailed roadmap identifying implementation needs and action items. A key outcome of these workshops was the development of a prioritized list initially created in 2008 and updated annually through 2012. This paper describes in greater detail how this list was developed and prioritized and how it has changed since it was initiated in 2008. Accompanying this list is a set of action items to overcome the various barriers identified.

The use of drilled shaft concrete piles is generally not a widespread method of stabilization of landslides along Alberta highways as a result of perceived high costs and the uncertainty of performance of these structures in the long term. However, over the last 30 years, the use of drilled shaft piles has been the preferred method of stabilization of various sites where conventional methods were not feasible either because of site constraints or not considered appropriate. This paper presents a case history of a roadway embankment slide for which the most appropriate remedial measure was determined to be the use of a tie-back drilled shaft concrete pile retaining wall as a result of the deep-seated nature of the slide, inability to relocate the roadway, and concerns over using a toe berm. Stabilized in 1997, the roadway and pile wall are still performing satisfactorily despite some observed roadway undulations and movements of the sideslope behind the pile wall. This paper addresses the details of the site and slide activity, the judgments exercised in deciding the locations and depth of the concrete piles, and the design and construction of the pile wall retaining system.

The presence of groundwater table (GWT) within a flexible pavement can have a pronounced detrimental effect on the mechanical response of its foundations and consequently on the structural performance of the pavement system as a whole. The related literature reveals that little work was done to rigorously model the impact of shallow GWT on the pavement's structural performance and investigate the sensitivity of this impact to the foundation's stiffness. In this paper, statistical factorial analyses were applied to numerical modeling to investigate the effects of GWT, foundations stiffness, and GWT-foundation stiffness interaction factors on the rutting of flexible pavements. A finite element model simulating the pavement foundations as nonlinear porous media governed by the Biot coupled behavior was set up first. The response of the model was evaluated for combination of design values of the GWT and foundation stiffness parameters each of which was defined at lower and upper levels (two levels-factorial design of experiments). Analysis of variance (ANOVA) method was then used to examine the effects of the factors analyzed on the pavement rutting. The analysis results showed that the GWT and its interaction effect with subgrade stiffness have significant influences on the pavement rutting. The detrimental effect of the GWT becomes more pronounced when the subgrade stiffness decreases, while such effect changes insignificantly with changing the stiffness of the granular base. The paper opens a new window for assessing the structural performance of flexible pavements under various GWT and foundation material conditions using the coupled finite element method in conjunction with the statistical factorial analysis approach.

Geothermal piles are increasingly used around the world as an innovative and sustainable method of harvesting shallow geothermal energy. Energy harvested through this technique can be used to partially meet the heating and cooling energy demand for residential and commercial buildings. Despite the growing recognition of the benefits of geothermal piles, the complex heat exchange through these piles is not yet fully understood. This paper describes a series of thermal tests performed on an instrumented model heat exchanger pile installed in a standard F50 Ottawa sand bed. Temperature measurements were obtained at different locations within the soil, on the pile surface, on the tank boundary, and at the inlet and outlet points of the circulation tube. Recorded temperature data are used to obtain time-dependent heat exchange efficiency of the model pile. The thermal tests presented in this paper provide valuable data on the nature of heat exchange through geothermal piles and on the thermal response of soil in the vicinity of a heat exchanger pile.

Micropiles are small-diameter grouted piles (typically of diameters less than 300mm). Micropiles are ideally suited for low headroom and limited work area conditions. Specially developed installation processes mitigate noise nuisance, vibrations to surrounding soils and structures, disturbance to the production operations in individual units, and disruption to the functioning of business locality, which makes micropiles suitable for underpinning and seismic retrofitting of structures. With a wide variety of potential applications, it is necessary to understand the behavior of micropiles under different loading conditions. Reliable experimental data on battered micropiles are rather scarce compared with that of vertical micropiles. This paper presents the results from an experimental study conducted to understand the response of vertical and battered micropiles with different length/diameter ratio (L/D) subjected to vertical and lateral loading conditions. The vertical load-carrying capacity was found to increase with increasing L/D ratio upto a 300 batter. The ultimate lateral load was found to increase significantly with increasing L/D ratios up to a L/D ratio of 30 and 48 for vertical and battered piles, above which the increase in ultimate lateral load for increasing L/D ratios was found to be insignificant. Furthermore, the ultimate load capacity and mode of failure of the micropiles is a function of the angle of batter, direction of batter, and the L/D ratio for vertically and laterally loaded micropiles. The details of the experimental model employed in the study and the associated failure mechanisms are described in this paper.

Geothermal energy is an increasingly demanding energy source in Europe and USA. Louisiana has a huge potential for geothermal energy. This paper describes the potential use of geothermal energy which can be extracted in Louisiana. In the paper, a 4-story building was chosen in New Orleans, Louisiana, which has a pile foundation with a total of 145 driven piles. A total of 16 energy piles from 16 pile groups were simulated in the analysis, and it is found that each 24.38 m-long single pile can extract a maximum of 1.83 (kW/hr) cooling load and 1.68 (kW/hr) heating load. Altogether, the 16 energy piles can give almost 19.9% of the total cooling demand and 68.12% of the total heating demand of the entire building. Further analysis was also done to compare the economic and environmental effects by gas, propane, oil, electricity and geothermal energy to heat/cool the building. If the total demand of heating and cooling is done by each of these energy sources, it is found that natural gas will be 13.6 and electricity will be 16 times more costly than geothermal energy. Moreover, natural gas and electricity will emit 1.8 and 1.7 times more CO2 than geothermal energy.

This paper describes wisdom of ancient engineering practice. The first wisdom is about a biology-based method for bridge-scour protection. A number of historical bridges across waterways in China served for more than 1000 years without significant structural damages. Protection provided by cultivated oysters is believed to be responsible for their excellent performance in scour protection. This offers a green approach to mitigate bridge scour. Another story is about natural hazard warning. A number of historical records indicated that major natural hazards are typically accompanied by abnormal behaviors of animals. The first successful prediction of earthquake occurrence is the Haining earthquake of China. The prediction and evacuation order was partially based on observed abnormal behaviors of animals. The paper also describes an innovative sticky-rick lime mortar used in ancient construction and bio-inspired sensors that potentially can improve existing understanding of bridge-scour mechanisms. In the authors' opinion, these historical heritages will continue to inspire emerging engineering practice.

The concept and structural benefits of prestressing cold-formed steel beams are explored in the present paper. In the proposed system, prestressing is applied by means of a high-strength steel cable located within the cross section of the beam at an eccentric location with respect to the strong geometric axis. The internal forces generated by the prestressing are opposite in sign to those induced under subsequent vertical loading. Hence, the development of detrimental compressive stresses within the top region of the cold-formed steel beam is delayed and thus the load-carrying capacity of the beam is enhanced. Owing to the precamber that is induced along the member during the prestressing stage, the overall deflections of the beam are also reduced significantly. In the present paper, finite-element (FE) modeling was employed to simulate the mechanical behavior of prestressed cold-formed steel beams during the prestressing and vertical loading stages. Following the validation of the FE modeling approach, a set of parametric studies was conducted, where the influence of the key controlling parameters on the structural benefits obtained from the prestressing process was investigated. The parametric results were utilized to determine how the benefits obtained from the addition of the prestressed cable can be maximized, demonstrating the significant enhancements in the performance of the cold-formed steel beam that can be achieved.

Tunnelling beneath piled structures may compromise the stability and serviceability of the structure. The assessment of potential structure damage is a problem being faced by engineers across the globe. This paper presents the outcomes of a series of geotechnical centrifuge experiments designed to simulate the effect of excavating a tunnel beneath piled structures. The stiffness and weight effects of piled structures are examined independently using aluminium plates of varying stiffness (`equivalent beam' approach) and the addition of weights supported by aluminium piles. Greenfield displacement patterns and results from pile loading tests are also provided. The variation of structure displacement profiles with plate stiffness, weight, and tunnel volume loss are used to illustrate the main effects of tunnel-pile interaction and the contribution of the superstructure to the global tunnel-pile-structure interaction. Results indicate that piles have a detrimental role in tunnel-structure interaction problems, whereas the superstructure stiffness and weight can, respectively, reduce and increase structure distortions and settlements. Finally, the potential for structural damage is evaluated by comparing structure and greenfield deflection ratios as well as resulting modification factors. The paper presents a unique set of results and insights which provide valuable guidance to engineers working across the ground and structural engineering disciplines.

Traditional paper-based methods for construction activity monitoring are inefficient and error-prone. In this paper, an automated approach is proposed for monitoring the progress of construction activities by tracking major construction equipment and bulk material, using sensor-based technologies. Data obtained from sensor-based technologies will be fused to determine the completed steps of the activities, and consequently to identify the overall progress of the activities. Also, human-generated data, such as daily site reports, will be used to support the sensor data. A rule-based approach is developed for fusion of the collected data. This paper describes the initial field tests that were performed to monitor the rebar installation activity at a pilot construction site. To collect data about the ongoing rebar installation activity, the embedded sensors (e.g., position and load sensors) of a tower crane anti-collision system, and the site reports and quantity takeoffs were used. Initial results show that the developed approach can estimate the progress of rebar installation activity with 98% accuracy.

In a typical construction project, a significant amount of information is communicated to various stakeholders at different phases of the project lifecycle. The communication of this information tends to be informal and ad-hoc in the majority of the cases, which makes it more susceptible to loss of information or misinterpretation. Earthwork operations, which are one of the main operations of construction projects, also struggle with the challenge of effective information communication. There is an apparent shortcoming regarding the unified structure for data and information exchange in this domain. The existing models and ontologies do not address the explicit semantic representation of the earthwork operations. Accordingly, there is a need for a knowledge model to formalize the communication of information in an efficient manner. An ontological model can be used to organize the domain knowledge so that it can be utilized and reused by the stakeholders, e.g., project managers, designers, etc. This paper purposes a framework to develop an ontology for earthwork operations to support and enhance data exchange and communication among different stakeholders in the project. The main objectives of this paper are (1) to formalize the knowledge in the earthwork domain, and (2) to build an ontology that captures this formalization. The ultimate result of this ontology, which is demonstrated by means of a case study, is to facilitate the development of data standards that can be shared in actual projects to accelerate project execution.

Selected papers from Geo-Risk 2017, held in Denver, Colorado, June 4–7, 2017. Sponsored by the Geo-Institute of ASCE.This Geotechnical Special Publication contains 53 peer-reviewed papers on the us...

ABSTRACT This paper describes an assessment of the bias, error and reliability associated with capacities and performances of axially and laterally loaded piles, designed according to API Recommended Guidelines [1,2]. We first identify the major sources of uncertainties affecting axial and lateral performances of piles in clay and sand, which are then assessed using available field and laboratory test data. These individual components of uncertainties are then integrated through a simple probability model for further reliability evaluation. Results from this research will help to direct future research efforts for reducing major uncertainties affecting pile performances, and to assist designers to better assess differences between various editions of API-RP2A Recommended Guidelines. In the long term, it will facilitate the development of design procedures which maintain a consistent level of safety between different site conditions, alternative pile configurations and structural and foundation subsystems. Only single piles are considered in this paper. Reliability of pile system is currently under investigation. INTRODUCTION Traditionally, the axial bearing capacity of a pile is calculated using a given pile capacity prediction method and a chosen set of soil parameters. In reality, the capacity of an offshore pile subject to storm loadings could differ significantly from the calculated capacity due to various factors and sources of uncertainties. First each pile capacity prediction method rests on some simplifying assumptions. Even if the institute soil properties at the pile location are perfectly known, some scatter is still expected between the measured and predicted capacities. This model error would vary among different prediction methods. For example, to evaluate the model error associated with a given pile capacity prediction method, untrained shear strengths are needed in each site to predict the capacity in clay. However, such strength values are based on a large range of sampling and testing techniques. In order to maintain consistency, a commonly available sampling/test method is generally adopted as the standard strength. Hence, the statistics of the model error assessed according to the standard strength values would only be applicable to a design situation where the same standard sampling/test method is used for its soil strength determination. If any other sampling/test method were used, a correction factor would be required to account for the discrepancy in soil strength values expected between that and the standard method. Second, a pile subject to storm loading does not necessarily have the same capacity as that measured at a conventional load test. For instance, load tests are generally performed within 50 days of pile installation; whereas the maximum load applied to a pile during a structure's lifetime may occur years after installation. For most normally consolidated clay where reconsolidation occurs around a pile, the capacity measured during load tests could underestimate the actual pile capacity. Third, the rate of load application during load test is generally much slower than the loading rate from waves. Since soil strength generally increases with loading rate, the capacity measured during load tests would likely underestimate the actual pile capacity. Correction factors are thus needed to account for each of these and other biases.

[EN] Although bridge fires pose a real threat, the topic is not covered in current design codes. This paper analyses information related to 154 cases of bridge fires, proposes classifying the damage levels suffered by a bridge during a fire, and establishes the main factors involved in bridge fire damage, which include: type of vehicle involved in the fire and its position, vertical clearance of the bridge, and the type of material composing the deck. The analysis shows that wooden bridges are the most vulnerable and that a tanker carrying gasoline under the bridge, or that is on the bridge and causes a serious spill under the bridge, is responsible for most of the fires that result in the collapse or demolition of the bridge., The research presented in this paper is sponsored by the Spanish Ministry of Education (Research Project BIA 2011-27104). The authors also thank Dr. J. Glassman for providing information for the present study and Dr. V. Yepes for his assistance. The authors are also grateful to D. Terrasa Diaz, J. Perez Armino, B. Black, and R. Campbell, who kindly gave permission to use the photos of Fig. 1.

[EN] One of the most critical stages for a structure s safety is its construction process, and this problem is even more acute in buildings with reinforced concrete structures. These structures are usually built by shoring successive floors, so that the most recently poured floor rests on the lower floors by means of shores. It is therefore vitally important to have calculation tools available to estimate the loads to which the shores and slabs will be subjected in each stage of construction. A number of calculation methods have been proposed to date, of which the one proposed by Grundy and Kabaila in 1963 is the best known and most frequently used. This paper analyzes the limitations of Grundy and Kabaila s method by means of a parametric study of finite-element method simulations that identified a large number of situations in which this method presented unsafe results in terms of the estimated loads on slabs. In many situations, therefore, applying this method could gravely affect a building s in-service behavior and durability. The paper s final objectives are to make the reader aware of the limitations of Grundy and Kabaila s method and the need to use the more refined methods that are now available to estimate the loads on shores and slabs in reinforced concrete buildings under construction, The authors would like to express their gratitude to the Spanish Ministry of Education, Culture and Sport for funding received under the FPU Program (FPU13/02466) and to the Generalitat Valenciana (GV/2015/063).

Conventional slope stability analyses have commonly been based on a deterministic approach. Various deterministic-based analysis methods developed to date can assess the stability of a given slope using the factor of safety. However, it has been strongly debated that the use of only the factor of safety does not explicitly account for the uncertainties in soil parameters. In light of this, this paper uses the finite element limit analysis methods and conducts a probabilistic-based analysis of fill slope for the specific case of two-layered undrained clay. Results obtained show that slopes with large variations in soil properties may present an extremely high risk of a slope failure and this cannot be known if only a deterministic-based analysis is performed. Thus, this shows that more soil investigations can be performed to reduce the variation of the soil properties thereby reducing the risk of a slope failure. Different probabilistic charts based on different coefficients of variation in soil properties are provided in this paper. This study demonstrates that the finite element limit analysis methods can be applied in a probabilistic analysis.

Research on the waterproof failure mechanism was conducted using the software ABAQUS based on the project of waterproof design. The method used in the paper was compared with the predecessor method. The results showed that not only the predecessor method was workable but also the method in the paper was reasonable. The waterproof failure mechanism was also revealed. The research showed that the leakage easily occurred on the contact surface of the sealing gaskets during the condition of the joint opening. However, the leakage easily occurred on the contact surface of the sealing gasket and concrete during the condition of joint dislocation.

The management and organization of a transfer station is a key characteristic and plays a decisive role in urban mass transit. This paper focuses on minimizing the transfer waiting time, so as to optimize the issue of synchronized and coordinated train connecting in a transfer station. In addition, three different influencing factors are summarized, including transfer forms, walking distance in the station and congestion degree of passenger flow. The relationships between these factors and transfer time are also revealed. Finally, this paper develops a model to obtain the minimum waiting time of transfer passengers in all of the transfer directions, laying a foundation of coordinating arrival time and departure time.

For a destination, there are many guide signs guiding to it. These guide signs form some guiding paths to the destination. But not all of the guiding paths can guide people to their destinations successfully. This paper presents an efficient model to solve the guiding accessibility optimization problem of guide signs. The goal of this optimization model is a plan for an optimal guiding path for each existing problematic guiding path which can not guide people to a certain destination successfully. In this model, the artificial bee colony (ABC) algorithm is employed as the main optimizer. In this paper, the cost of each planned guiding path includes two parts, the path length, and the number of deployed new guide signs. The optimal planned guiding path is obtained by minimizing the cost. Finally, the proposed model is applied in a typical area and the genetic algorithm is employed as the contrast for comparison. The experimental results show that the ABC algorithm performs better for solving the guiding accessibility optimization problem of guide sign system than the GA algorithm does.

With the development of traffic motorization, urban traffic problems persist. In order to overcome traffic problems, it is imperative to develop a comprehensive bike-sharing system. However, the current bike-sharing system faces the challenges of site selection and determining the number of slots needed for rental stations. Therefore, this paper will take the bike-sharing system as its starting point and focuses on the layout of the stations. Based on the hierarchical model, an optimal model with capacity constraints for the system’s location is studied to minimize the walk cost for users, setup cost and penalties. With the model successfully solved by LINGO, this paper will also demonstrate the whole process of the planning with an instance that verifies the efficiency and feasibility of the model. The study’s results show the significance of optimizing the public bike rental station layout on solving the “last mile” problem.

In order to study the suitable conditions of different reform plans of separating trucks from the passenger vehicles and provide evidence and guidance for reforming the system of separating trucks from the passenger vehicles, this paper provides an index system, including delay, times of changing lanes, coefficient of speed variance and so on. What’s more, this paper carries out the analysis to this index system by applying the method of principle component analysis (PCA) and gets the selection and evaluation methods of reforming the system of trucks from the passenger vehicles. It confirms the effectiveness of the method by comparing it with the other methods, which are the mainstream in current through sequence-number summation theory. The results show that the method of PCA is more effective than other comprehensive evaluation methods when they are used to evaluate the efficiency of reforming the system of separating trucks from the passenger vehicles.

Now it is the trend of government home and abroad more transparency and providing open data for public access and properly tapping. Traffic data are an important part of these data. This paper presents the big traffic data visualizing procedures and illustrates an integrated open source platform with R Shiny. This paper also presents some tapping data tools and illustrates with corresponding traffic feature examples. Properly mining the big traffic data by the interested members will contribute to solve the traffic congestion problem to some degree.