Construction recently began for the Vertex project, a commercial site plan designed by LandTech, located at 5320 Kingston Pike in Knoxville, TN. The project includes a commercial retail building and a parking lot with pervious interlocking concrete pavers for stormwater management.
The new 2017 construction general permit (CGP) issued by the Environmental Protection Agency (EPA) went into effect on February 16, replacing the 2012 CGP.
According to the National Association of Home Builders (NAHB):
“The CGP takes effect Feb. 16 and will last for five years. While it’s applicable in only New Mexico, Idaho, Massachusetts and New Hampshire, this permit provides other states with a model for developing their own stormwater management requirements.”
“Thanks to new language, enforcement is much clearer and more reasonable for active construction sites. EPA is signaling a move away from focusing enforcement actions on minor details of onsite Stormwater Pollution Prevention Plans (SWPPPs) to make them a more effective compliance tool. The new permit states, “The SWPPP does not establish the effluent limits that apply to your site’s discharges.”
“Still, the new permit is far from perfect: EPA has introduced controversial language that considers all builders on a shared site “jointly and severely liable” for compliance with permit terms, including violations of “shared” treatment ponds and other features.
NAHB filed comments arguing that this type of liability framework is illegal, because operators often work on a site at different times, and cannot legally or physically control the activities of others.”
source: http://nahbnow.com/2017/01/2017-gcp-big-wins-but-liability-concerns-remain/
The recent flooding event at Lake Oroville Dam in California illustrates the amazing destructive power of water. I’ve done some dam failure modeling and mapping, but this video from PBS News Hour shows the real world results.
There are a lot of recent technologies that have impacted the civil engineering, land surveying and construction industries. Technologies such as GPS, machine control and drones just to mention a few.
Another new technology that could revolutionize the construction industry is 3D printing.
According to Wikipedia, 3D printing is defined as:
“3D printing, also known as additive manufacturing (AM), refers to processes used to synthesize a three-dimensional object in which successive layers of material are formed under computer control to create an object.”
The 3D printing industry is starting to develop technology to use concrete as the material for making objects. The article 3D Printers Can Now Print Concrete from the website Curbed explains how one university is printing concrete structures.
This video was included in the article linked above, and describes the 3D printing process for concrete structures:
In previous posts, we’ve discussed the low pressure pipe (LPP) subsurface sewage disposal system (SSDS) designed by LandTech Engineering & Surveying for the Sunshine Acres Campground in Newport, TN. This week, we conducted a pressure test to confirm the LPP system operates as designed.
According to the EPA LPP System Fact Sheet :
“A LPP system is a shallow, pressure-dosed soil absorption system with a network of small diameter perforated pipes placed in narrow trenches.”
A LPP system is a good alternative for land development projects without public sanitary sewer systems available.
The Tennessee Department of Environment & Conservation (TDEC) requires level trench bottoms, 18″ to 22″ deep, 12″ wide, and spaced with a minimum of 5′ center to center spacing. The perforated pipe diameters typically range from 1″ to 2″, with a minimum 3′ pressure head (1.3 pounds per square inch) at the end of the pipe.
The system pressure is tested by placing a 3′ vertical height pipe at the end of the perforated pipe. Gate valves are operated in the pipe system to adjust the system pressure until water just starts to flow out of the 3′ vertical pipe segment.
Below are photographs from the system test.
1. Photo – Pump tank riser:
2. Photo – Pump control panel:
3. Photo – Force main pipe from pump tank to disposal field:
4. Photo – Automatic distribution valve (ADV) that diverts flow from pump tank to manifold pipes at disposal field cells:
5. Photo – Manifold pipes from ADV to disposal field cell trenches:
6. Photo – Disposal field trenches with 3′ vertical length pipe segments at each end for pressure testing:
As an engineer, it’s always satisfying to see a system work as designed.
Please contact us if you’d like to discuss LPP systems or your land development project. http://landtechco.com/contact_us
Every once in a while I come across an interesting article that I think is of interest to the general engineering and surveying community. I just read a short Tech & Science article on the Newsweek website called “Scientists Create the Superman of Metals”, and thought I would share it on our blog.
A group of scientists say they have created the Superman of metals, a material so strong and lightweight it could lead to the creation of faster vehicles and revolutionize the airline and automotive industries.
Engineers at the University of California, Los Angeles, used a combination of ceramic silicon carbide nanoparticles and magnesium. The new metal boasts a stiffness-to-weight ratio that far surpasses other strong metals that engineers have reliably used for generations. The metal is also capable of absorbing and withstanding high heat without having its integrity altered.
You can read the entire article here: http://www.newsweek.com/scientists-create-superman-metals-409031
LandTech has gotten the opportunity to work on a wide variety of projects that has exposed us to unique construction technology. We’re performing construction surveying stakeout of a project that is utilizing a Rammed Aggregate Pier (RAP) system.
Geopier Foundation Company, a subsidiary of the Tensar Corporation, developed the first RAP system in 1989. According to their website:
Geopier Rammed Aggregate Pier™ (RAP) systems are efficient and cost effective Intermediate Foundation® solutions for the support of settlement sensitive structures.
Geopier® technologies are constructed by applying direct vertical ramming energy to densely compact successive thin lifts of high quality crushed rock to form high stiffness engineered elements. The vertical ramming action also increases the lateral stress and improves the soils surrounding the cavity, which results in foundation settlement control and greater bearing pressures for design.
Depending on site requirements, RAP systems can be installed using replacement or displacement methods. The unique installation process utilizes vertical impact ramming energy, resulting in unsurpassed strength and stiffness. RAP systems are used to reinforce good to poor soils, including soft to stiff clay and silt; loose to dense sand; organic silt and peat; variable, uncontrolled fill; and soils below the ground water table.
See more at: http://www.geopier.com/Geopier-Systems/Rammed-Aggregate-Pier-Systems
Land surveying has seen many technological advancements in recent decades, including electronic distance measurement, global positioning systems, and robotic total stations. The next big advancement could be the use of unmanned aircraft systems (UAS) or drones.
In recent years, the biggest hurdle hasn’t been technology, but rather regulatory. Drones operate in federal airspace, and by law requires an FAA license to operate.
A recent article in Fortune Magazine indicates the FAA has worked with the UAS industry to streamline the approval process for granting licenses to operate drones. http://fortune.com/2015/08/09/faa-commercial-drone-permits/
Just one year ago the ability to operate commercial drones in the U.S. was more concept than reality. Only two companies in the country were cleared by the Federal Aviation Administration (FAA) to operate those types of drones, and they were located in the far northern hinterlands of Alaska. One year later, the commercial drone industry looks drastically different. On Wednesday the FAA announced that it had approved more than 1,000 applications from companies seeking to operate commercial drones, and currently approving applications at a rate of roughly 50 per week.
That news is significant, considering that roughly a dozen companies were approved to operate drones commercially at the beginning of 2015. Since then, the unmanned aircraft systems (UAS) industry and the FAA have worked to streamline the approval process. The agency has also loosened certain aspects of its commercial drone regulations to allow approved companies greater flexibility in how they use commercial drones.
Those efforts have driven a drastic uptick in the number of companies approved to fly under so-called “Section 333 exemptions” as well as a broadening of the applications for which these drones are employed. The Association for Unmanned Vehicle Systems International (AUVSI) recently examined the first 500 commercial drone permits issued by the FAA and found exemptions spanned 20 major industries across 48 U.S. states.
The AUVSI examination also revealed “general aerial surveying” constituted the largest sector for commercial drone permits issued by the FAA.
You can review the authorizations granted by the FAA via the Section 333 exemptions here: https://www.faa.gov/uas/legislative_programs/section_333/333_authorizations/
Drones have a great potential to impact the civil engineering and land surveying industries. It’s sure to be something we keep our eyes on for the future.
The EPA and U.S. Army Corps of Engineers (USACoE) have been working to more clearly define the federal government’s authority to protect waterways by clarifying the definition of “waters of the U.S.”. However, there has been much disagreement about the limits of federal authority versus state authority and private property rights.
A Federal Court has handed down a stay on the new rule by the EPA and USACoE, saying it is likely illegal. http://thehill.com/policy/energy-environment/256493-court-blocks-obamas-water-rule-nationwide
A federal court ruled Friday that President Obama’s regulation to protect small waterways from pollution cannot be enforced nationwide.
In a 2-1 ruling, the Cincinnati-based Court of Appeals for the Sixth Circuit delivered a stinging defeat to Obama’s most ambitious effort to keep streams and wetlands clean, saying it looks likely that the rule, dubbed “waters of the United States,” is illegal.
“We conclude that petitioners have demonstrated a substantial possibility of success on the merits of their claims,” the judges wrote in their decision, explaining that the Environmental Protection Agency’s new guidelines for determining whether water is subject to federal control — based mostly on the water’s distance and connection to larger water bodies — is “at odds” with a key Supreme Court ruling.
These issues are important to civil engineers working on land development projects because it will determine if the regulating authority is the federal government (EPA and/or USACoE), the state (TDEC in Tennessee), or the local government (City of Knoxville for example).
For the State of Tennessee, rules regarding work in waterways are generally regulated by the Tennessee Department of Environment & Conservation (TDEC). For example, anyone proposing to alter a stream, river or lake must obtain an Aquatic Resource Alteration Permit (ARAP). Examples of work requiring a permit include dredging, streambank stabilization, channel relocation, water withdrawals, and road crossings. For more information, visit TDEC’s website https://www.tn.gov/environment/article/permit-aquatic-resource-alteration-permit
Please feel free to contact LandTech’s staff of civil engineers and land surveyors to assist you with any issues relating to ARAP permitting. http://landtechco.com/home
For civil engineers and land surveyors, it’s conventional wisdom that in order to reduce traffic congestion you have to build more roads. However, according to this interesting article in the mathematics magazine “Plus Magazine”, there are several examples where traffic has improved after removing roads.
https://plus.maths.org/content/want-less-traffic-build-fewer-roads
The closing of 42nd street, a very busy crosstown road in New York City, during Earth Day in April 1990, was expected to cause a traffic nightmare. Instead, as reported in The New York Times on December 25, 1990, the flow of traffic actually improved.
In 2003, the Cheonggyencheon stream restoration project began in Seoul, removing a six-lane highway. The project opened in 2005, and besides substantial environmental benefits, a speeding up of traffic was observed around the city.
The article also mentions the reverse phenomenon of negative effects seen with expanding a road network:
If closing roads might help traffic flow, the negative effects of expanding a road network can be observed as well. For instance, in the late 1960s the city of Stuttgart decided to open a new street to alleviate the downtown traffic. Instead, the traffic congestion worsened and the authorities ended up closing the street, which improved the traffic.
The theory behind this phenomenon is described below.
Stories like these abound and as you might suspect, some mathematics is lurking behind them all. Indeed, in 1968, the mathematician Dietrich Braess, working at the Institute for Numerical and Applied Mathematics in Münster, Germany, proved that “an extension of a road network by an additional road can cause a redistribution of the flow in such a way that the travel time increases.” In his work Braess assumed that the drivers will act selfishly, each of them choosing a route based on their own perceived benefit, with no regard for the benefit of other drivers. It’s an assumption that reflects the harsh conditions of rush hour traffic rather well!
The phenomenon Braess observed, now called the Braess paradox, is not really a paradox, but just unexpected behaviour showing that we are not very well equipped to predict the outcomes of collective interactions.
Although there are many positive effects to traffic congestion by expanding roadway networks, there can also be unintended consequences and we may not necessarily realize the benefits we expected.