NUASCE

Today, Jason Sobel gave a great presentation on the traffic engineering, analysis, and simulation for the preparation of the preliminary environmental studies involving the Bus Rapid Transit (BRT) Route in the Urban Ring Project.  The purpose of the BRT route in the Urban Ring is to facilitate travel between the communities of Boston.  The first step in the analysis of the project was to look at future traffic projections for bus routes and private shuttles in 2030.  There will be greater employment in the area as well as a much greater population, increasing the demand for a system like this.

One of the advantages the BRT would have over the MBTA is having larger and more substantial stations that are spread further apart.  Because they are space slightly less frequently, the busses would make fewer unnecessary stops and would therefore have less travel time for users.  The BRT would also have better traffic controller information as well as still connecting with the MBTA and commuter rail.

The main focus of this presentation of the BRT was the engineering challenges faced at the critical location of Commonwealth Ave. at the Boston University Bridge.  AECOM gave several proposed options for implementing the BRT in this area.   Some options included ideas such as the creation of new structures, a separate route built for the BRT, and the relocation of the Boston University Academy building.  AECOM also played a very interesting simulation video made for one of the proposed solutions.

NSTAR, the largest Massachusetts-based electric and gas utility company gave a presentation today focusing on their environmental engineering activities.  Presenter representing NSTAR included; Principal Engineer Daniel Watton, Senior Engineer Eric LaMontagne, Engineer Kristen Trudell, Co-op Engineer Andy Crawford, and Co-op Engineer Raj Punjabi.

NSTAR has well over 3,000 employees and serves over 100 communities with 1.1 million electric and 300,000 natural gas customers.  The main focus areas for their environmental engineering are environmental sustainability, maintenance and construction environmental compliance, facility environmental compliance, and oil and hazardous material (OHM) release management.

For environmental sustainability, NSTAR recycles materials such as utility pole wood, dielectric fluid, waste motor oil, batteries, copper, aluminum, lead, steel, etc.  They look to use renewable products such as vegetable oil which is non-toxic, bio-degradable, non-petroleum based because it comes from a vegetable source.  Reducing their Carbon footprint is also very important to NSTAR.  The company tries to achieve this by reducing the use of energy and water, efficient fleet fuel use, and reducing the loss of SF6 gas, which has a great global warming potential.

NSTAR also talked about the engineering challenges faced with a specific example of the 2,000 gallon leak found at station 49 in Kenmore Square.

Peter Finch, project director from Amtrak gave a great technical presentation on the work done for the replacement of the vertical lift span of the Thames River Bridge located in Groton and New London, CT.  This bridge has a lot of traffic with about 38 trains per day and over 1600 annual openings, including opening for the United States Navy and Coastguard.

Some of the major design elements for this project were replacing the bascule, modifying the channel piers and constructing two 135 foot lift towers for a span of 188 feet, while retaining the approach spans and finding an efficient way to remove the old counterweights.

A major problem faced during this project was the settling of one of the piers after construction.  This became most important when the settlement did not appear to be stopping.  The settlement caused sinking and tilting of the pier which prohibited the opening of the bridge.  This problem was eventually solved through permeation grouting which filled the voids that had been causing settlement underneath the pier.

Though there were unforeseen challenges in the replacement of this lift span, the problems were solved effectively.  With a goal of July 4th, the bridge was complete for limited scheduled openings by July 1st and the approach spans are ready for painting in the near future.

Number of Students: 56
Number of Advisers: 2
Number of Faculty: 3

This week’s lecture featured Robert Nagi from VHB on the development of wind farms. Wind farms can be land based, shore based, or ocean based. The most efficient locations are offshore in the ocean, because of the constant availability of powerful wind gusts. Civil engineers play a large role in wind farm development. The process requires wind assessment, design, environmental studies, land acquistiion and permitting, manufacturing and construction, and transportation. There is a growing need to test wind blades for characteristics including bending and vibration. Construction and manufacture of the blades usually happens far away from testing facilities, so transportation is a very important issue.

Since wind blades can be huge, around 30 to 40 m in length, transportation can become a difficult procedure, especially through dense areas. There are many factors that need to be taken into account, such as the turning radius of the truck carrying the wind blade. Operators must watch for obstacles in the path of the container in 3 dimensions, including signs above, dips in the roadway, overhead bridges, etc. One example of a VHB job is at the Charlestown site in Massachusetts, which is very close to the ocean. The challenge with this site is that it is necessary to travel through neighborhoods on city streets. A solution to this challenge is the use of a special expandable truck with steerable back wheels, which helps to negotiate turns that would be impossible with a normal static truck. The use of new technology is helping to improve wind blade transport for the future.

For this week’s lecture, Mauro Scali from Simpson, Gumpertz, and Heger spoke about the process and applications of concrete petrography.   Concrete petrography is the study of hardened concrete micro-structure using microscopic techniques.  This study can help with the understanding of concrete conditions that lead to the failure of structures.  Mauro explained that the answers to questions on how and why a structure collapsed can be found by knowing exactly where to look.  It is important to not only understand the problems in the concrete, but also how to repair the issues.

The process begins with an important visual examination of the concrete.  Fractured aggregate and inadequate bonds in the concrete can be discovered just by looking at a photo of a structure.  Photographs of existing conditions are vital because they can show factors in the surrounding environment affecting concrete.  Next a cross cut section sample can also reveal more imperfections in the concrete.  Finally, microscopic examinations of ground down samples will show important information such as the degree of cementation or the water/cement ratio.   There are numerous causes for specific issues in concrete.  Cracking caused by drying shrinkage, corrosion, and freeze/thaw cycles or an improper water/cement ratio will add to structural failures.  One way to counteract cracking is with air entrainment.  Very small air voids added to concrete act as buffers that relieve expansive stress due to freezing, etc.   Concrete petrography is key in determining how a structure will fail.

Special thanks to Abe Finkelstein, our Secretary, for the write up.

Pat Barb S&F Concrete
25 February 2009

Number of Students: 41
Number of Advisers: 1

This week’s lecture featured Pat Barb from S&F concrete.  Pat spoke about the different aspects of concrete construction projects, specifically the Clarendon condominium project in Boston, MA.  This project involved both conventional construction and up-down construction methods.  Up-down construction allows for the development of the building’s superstructure while excavation below grade is still in progress.  For the first time, cast-in-place concrete was used in an up-down construction project.  In order to carry out this process, it was necessary to determine how to transfer temporary loads from the superstructure to prevent a collapse on unfinished supports.  This was accomplished with the use of bearing plates at the top of load bearing elements and continuous reinforcing for columns and shear walls.  Construction began with the pouring of a deep foundation, followed by the slurry wall and caisson installation.  Water underneath the excavation holes caused problems with the curing concrete, so the slurry wall needed to be deep enough to counteract this.

Pat also spoke about the different considerations when choosing form work systems on a construction project.  These considerations included safety and intended use for desired quality, schedule and available equipment, and labor/productivity costs.  Usually, jump systems or rail climbing systems are used.  However, new perimeter protection systems can be used to improve safety, efficiency, and overall construction progress.  These systems involve attaching plywood around construction areas to provide a safe enclosure for workers and for the public below, minimizing fall exposure and falling debris.

Special thanks to Abe Finkelstein, our Secretary, for the write up.

Developing a Unique Centerline Rumble Strip Pattern Professor Daniel M. Dulaski
18 February 2009

Number of Students: 43
Number of Advisers: 1
Number of Faculty: 1
For this week, Professor Dulaski gave a lecture on a multidisciplinary approach for developing rumble strip patterns.  Traffic control devices are used to provide important information to a driver.  Rumble strips are traffic control devices that alert drivers of the edge of the road with sound and vibration.  These rumble strips are positioned mainly on the right hand shoulder, preventing drivers from straying too far off of the road.  However in some areas, a rumble strip has been introduced to the centerline to prevent drivers from drifting into other lanes or traffic medians.  Although helpful in some cases, centerline rumble strips could cause major problems when drivers instinctively veer left into oncoming traffic, especially in conditions with poor visibility.  In an initial study, 27% of drivers corrected left when presented with a rumble pattern.

Possible solutions to this problem involve making the centerline rumble pattern unique enough to be discernible by drivers when encountered in any weather condition.  A great deal of fieldwork was carried out to record vibrations and sound from existing rumble strips.  It was determined that there is no perceptable difference in sound or vibration between the centerline or shoulder, so without a unique pattern, a driver would have trouble correcting properly when veering off the road.  A centerline pattern was developed for new strips with more spacing to create a distinct impression on drivers.  In the previously mentioned study, drivers were able to correct properly after being conditioned to the new centerline rumble strip pattern.  These improvements in traffic control devices will greatly improve lane keeping ability, and help to save lives.

Special thanks to Abe Finkelstein, our Secretary, for the write up.

Transportation Technology

Joseph Herr
VHB
11 February 2009

Number of Students: 39
Number of Advisers: 2
Number of Faculty: 4

This week’s lecture focused on the importance of new technology used in transportation engineering. Transportation technology has evolved a great deal over the years. For example, traffic signals have gone from mechanical boxes to very complex electronic systems that have improved safety and efficiency at nearly every road and intersection. Engineers have developed advanced traffic management systems to control and monitor information to determine the amount and rate of vehicles crossing intersections, vehicle speed, occupancy, size, etc. Breakthroughs in communication equipment have allowed for much more efficient data communication between traffic devices. Where copper wire used to be the main source of data transfer, new fiber optic cables and wireless radio signals have been implemented. Vehicle detection has become more advanced with video based methods using cameras at intersections. Inductive loops placed inside pavement near traffic signals, and magnetic, ultrasonic, or infrared sensors are also now used to detect vehicle information.

Transit signal priority systems have been designed using infrared sensors and g.p.s. locators. These systems have the ability to detect priority vehicles such as ambulances or fire trucks to allow for precedence when crossing intersections. This technology can also be used to assist public transportation, making bus travel times shorter and more accurate. Although successful and helpful in certain areas, transit signal priority systems have not been implemented in Boston or a similar city due to the fact that during busy travel times, changing the flow of traffic lights could block up city streets and delay commutes. VHB has worked on projects such as in Springfield, MA where transit priority was used for a new express bus route. Other projects include the Providence Convention Center garage, the ITS system in the Florida Keys, intersections in Presque Isle, ME, and custom designed technology for Cape Canaveral, Florida to fit rocket sized vehicles through intersections.

Special thanks to Abe Finkelstein, our Secretary, for the write up.

Special thanks to Abe Finkelstein, our Secretary, for the write up.

This week’s lecture was given by Nancy May, the Interim V.P. of Facilities here at Northeastern University.  The lecture was on the past, present, and future for the institutional master plan of the Northeastern campus.   The university has around 15,989 undergraduates, with 7,385 living in on-campus housing.  With such a high demand for housing, the university has seen it as a priority to provide more space around campus for residence halls.
Since Northeastern was originally a commuter type school, most of the free space on campus was used for surface parking lots.  Since that time, most of theses spaces have been converted to dorms or classrooms, with the exception of a few existing parking lots.  These changes have been implemented with the Institutional Master Plan (I.M.P.), which has several different phases.  The I.M.P. phase in 2000 began with the addition of the West Village residence halls.  The plan set up to begin construction on West Village A, followed by West Village B, C, D, E and so on.  Each building would be re-named after a donor was found, hence the naming of West Village D as the Behrakis Health Science Center.  There have been several amendments to the I.M.P. to include new residence halls and renovations of existing buildings on campus.   Amendment 1 was to include West Village H with 16 stories, amendment 2 included more beds in West Village F, and amendment 3 included the new residence hall, Parcel 18 west.  Also the amendments included the renovation of the law school building in Dockser Hall and possible residences in Cullnane Hall.  Of the new construction, the goal was to have both Dockser hall and Parcel 18 get Leed certification.
The planning process for Northeastern University began with an academic plan, followed by strategic plans to have academic goals met.  The physical plan was developed after this academic plan, which allowed for the development of the Institutional Master Plan for new residences on campus.   Although most major construction has finished, there have been minor difficulties during the planning process.  Many of the neighboring communities have had issues with the expansion of the Northeastern campus and have been against new construction in certain areas.  The university is under strict requirements on where and when they have to build new residences.  That being said, a new building is in the planning phase for new apartment style residences on campus near St. Botolph street.

Special thanks to Abe Finkelstein, our Secretary, for the write up.