Stabilization of High Soil and Rock Cut Slope by Soil Bioengineering and Conventional Engineering

Author(s):  
Robbin B. Sotir ◽  
Michael A. McCaffrey

Construction of a 274.5-m-long (900-ft) and 24.4-m-high (80-ft) soil (upper) and rock (lower) cut slope on the eastbound side of the Massachusetts Turnpike at mile mark 94.1 eastbound for the proposed interchange with Route 146 combined conventional engineering and soil bioengineering solutions. Geologic mapping identified three sections (east, middle, and west) that had different patterns of rock discontinuities, which controlled rock cut design. Each required a different slope design for a stable rock cut. The soil cut design was controlled by soil density, groundwater seepage, and erosion potential from seepage and surface runoff. Soil bioengineering was used to control surface drainage and erosion on the cut soil slope above the 12.2-m-high (40-ft) rock cut and rapidly revegetate the disturbed soil slope, which addressed the project's environmental and aesthetic goals. Conventional crushed-stone drains augment the living soil bioengineering drains. Woody vegetation was used to reinforce the cut soil slope surface. Branches from native living woody plants were installed into the slope face, offering surface reinforcement. Root development along branch lengths provided additional reinforcement. The hydrologic regime was modified as growing plants remove moisture through transpiration and embedded bundled branches channel water off the slope. Basic soil bioengineering stabilization principles by using live fascines and brush layers for soil and rock cut slope stabilization are presented. Discussions include preconstruction conditions, environmental benefits, vegetation harvesting and design, installation, and performance as of October 1996. Cut slope stabilization through soil bioengineering produced an environmentally, aesthetically, and mechanically sound solution, illustrating the benefits of combined technologies.

Author(s):  
Marco A. R. Nascimento ◽  
Electo S. Lora ◽  
Guido A. Sierra R. ◽  
Manuel A. Rendon

Biodiesel is an alternative fuel that has become more attractive recently because of its environmental benefits and the fact that it is made from renewable resources. As it can be blended in any proportion with mineral Diesel, and there are several reports which presented substantial reductions in emissions of unburned hydrocarbons, carbon monoxide and particulate in IC engines without reducing the output power significantly. The aim of this work was to perform an emissions and performance experimental analysis to evaluate and compare the use of Biodiesel obtained from different sources, Castor, Soy and Palm Oil, on a 30 kW regenerative gas micro turbine engine installed in the laboratories of the Federal University of Itajuba´ – Unifei, Brazil, at different power levels at steady state condition. All the fuels were characterized in terms of its viscosity and heat value, and the thermal performance and the emissions were measured. In all cases, it was performed a comparison between the obtained results with Biodiesel and Diesel. None of the fuels presented any problem related to atomization process in the related tests, and have shown no significant changes in performance of the microturbine reaching levels of around 26% of thermal efficiency. The minimum Heat Rate obtained at full load, was for the Biodiesel from Palm oil case, and the maximum was for Castor oil with a value 8.38% higher than when operated with Diesel. In Addition, when measuring pollutants emissions in the exhaust gases, it was observed a slightly increment in CO and a reduction in NOx concentration.


Author(s):  
Barbara Widera

The paper addresses the topic of nature-based solutions applied in the architectural and urban design. These ideas are analyzed in the context of the opportunities they create for the humanity in terms of the sustainable growth and environmental protection. Nature-based solutions are inherently taken from nature. The first part of the paper presents their tremendous potential to be energy and resource-efficient, and resilient to change. In the second part of the research particular concepts driven from nature (copied form nature or inspired by nature) proposed for the buildings and cities are described and evaluated. The author discusses their functional usefulness, spatial appropriateness, adaptation to local conditions, end-user comfort, environmental benefits and the possibility of duplication. Nature-based solutions applied in urban planning can make cities more climate resilient and contribute to ecosystems restoration. The paper describes how sustainable urbanization can stimulate economic growth, make cities more attractive and enhance well-being of the inhabitants. It is also explained how particular buildings can benefit from the concepts driven from nature e.g. by increasing their energy efficiency and performance in terms of raw material consumption. In purpose to properly response to the climate challenge, humanity has to establish a new kind of partnership with nature. Using nature-based solutions should be considered as an important part of this approach. The concepts presented in this paper show some of the most promising options, such as integration of living systems with built systems and innovative combinations of soft and hard engineering. In conclusion some of the most promising nature-based solutions for climate resilient buildings and cities are indicated


2010 ◽  
Vol 41 (3) ◽  
pp. 13 ◽  
Author(s):  
Elena Bresci ◽  
Federico Preti

Quotations and references, taken from old texts on stream channel works (today classified as belonging to soil bioengineering interventions), are presented and discussed. Part I of the same study previously showed a similar analysis on slope stabilization [Bresci 2002]. The selected quotations are reported in a chronologic order to highlight the historical evolution in each work description and, in particular, the instructions and adjustments to put on when carried out. Where suggestions for vegetation material selection and numerical indications are found in the analyzed texts, they have been reported translated into English. The selection of the analyzed works has been carried out among those utilized for streambank protection, a sector where more often vegetation is utilized. Also in this case (Part II) it is demonstrated that bioengineering techniques clearly originate from forest watershed management.


2020 ◽  
Vol 124 (1277) ◽  
pp. 1016-1054
Author(s):  
R. Norouzi ◽  
A. Kosari ◽  
M. Hossein Sabour

ABSTRACTExtensive research in recent years has focused on improving the current loss-of-control prevention systems and developing new strategies for safe path planning of the impaired aircraft. Success in developing such systems requires a comprehensive perception of the influence of damage on the aircraft’s dynamic behaviour and performance, and the effect of various failure degrees on the flight envelope confinement and the remaining safe maneuvers. This paper comprehensively describes the effects of lateral control surface failure on the NASA Generic Transport Model (GTM) flight envelope, defined by a set of attainable steady-state maneuvers herein referred to as trim points. The study utilises a large database of high-fidelity maneuvering flight envelopes computed for the unimpaired case and wide ranges of the aileron and rudder failure cases at different flight conditions. Flight envelope boundary is rigorously investigated, and the key parameters confining the trim points at different boundary sections are identified. Trend analyses of the impaired flight envelopes and the corresponding limiting factors demonstrate the effect of various failure degrees on the remaining feasible trim points. Results can be employed in emergency path planning with potential uses in the development of aircraft resilient control and upset recovery systems.


Author(s):  
A. Alexiou ◽  
A. Tsalavoutas ◽  
B. Pons ◽  
N. Aretakis ◽  
I. Roumeliotis ◽  
...  

At present, nearly 100% of aviation fuel is derived from petroleum using conventional and well known refining technology. However, the fluctuations of the fuel price and the vulnerability of crude oil sources have increased the interest of aviation industry in alternate energy sources. The motivation of this interest is actually twofold: firstly alternative fuels will help to stabilize price fluctuations by relieving the world wide demand for conventional fuel. Secondly alternative fuels could provide environmental benefits including a substantial reduction of emitted CO2 over the fuel life cycle. Thus, the ideal alternative fuel will fulfil both requirements: relieve the demand for fuels derived from crude oil and significantly reduce CO2 emissions. In the present paper, the effects of various alternative fuels on the operation of a medium transport/utility helicopter are investigated using performance models of the helicopter and its associated turboshaft engine. These models are developed in an object-oriented simulation environment that allows a direct mechanical connection to be established between them in order to create an integrated model. Considering the case of a typical mission for the specific helicopter/engine combination, a comparative evaluation of conventional and alternative fuels is then carried out and performance results are presented at both engine and helicopter level.


1984 ◽  
Vol 21 (4) ◽  
pp. 657-662 ◽  
Author(s):  
Edward Nicholas Bromhead

Recently, J. N. Hutchinson has collected data on the design and performance of trench and counterfort drains. This article presents an analytical solution to one of these cases, that of seepage into counterfort drains which penetrate the full thickness of a layer of soil, down to the impermeable base on which it rests. The soil is assumed to have uniform permeability.The findings of a small study, by Hutchinson, of seepage patterns to such drains, made with the use of finite element methods, are found to be validated by the theoretical approach in this article. This solution also provides a convenient benchmark against which approximate numerical methods can be assessed.Finally, a design chart based on the theory is presented, with examples of its application to the design of counterfort drain installations for slope stabilization.


2018 ◽  
Vol 15 (1) ◽  
pp. 37-50 ◽  
Author(s):  
Luca Giupponi ◽  
Gigliola Borgonovo ◽  
Annamaria Giorgi ◽  
Gian Battista Bischetti

Sign in / Sign up

Export Citation Format

Share Document