Separation Function of Geotextile for Road Construction on Soft Subgrade Soil.

Gravel surfacing is commonly used on low-volume roads in rural areas of the United States to form farm-to-market networks that contain more than a million miles of unpaved roads. Some of these roads carry appreciable amounts of trucks and farm machinery. Some of these roads, if properly designed and constructed, can last a long time. One such road is in Hand County, South Dakota. This road was constructed in 1963 and has never been rehabilitated or reconstructed since its construction, and it has shown excellent performance for more than 37 years. This road normally carries less than 200 vehicles per day, but significant numbers of heavy trucks use the road. This exceptional performance led to an investigation of the reasons why that road lasted as long as it did without major maintenance or rehabilitation. Although this type of road construction is common in other nations, under different names, the practice of constructing this type of road in the United States was done without documented specifications. The main objectives of the study were to determine all factors that contributed to the longevity and the remarkable performance of this road through field and laboratory investigations. Field investigations with a dynamic cone penetrometer (DCP) revealed that both the quality and the quantity of aggregate base were more than adequate. Although the subgrade soil was classified as A6 according to AASHTO soil specifications, it provided good support according to DCP data. Tests of the flatness and elongation of the coarse aggregate and the angularity of the fine aggregate also revealed satisfactory results. Gradation tests also revealed compliance with specifications.

Download Full-text

Enhancing soft subgrade soil with a sewage sludge ash/cement mixture and nano-silicon dioxide

Environmental Earth Sciences ◽

10.1007/s12665-016-5432-9 ◽

2016 ◽

Vol 75 (7) ◽

Cited By ~ 2

Author(s):

Deng-Fong Lin ◽

Huan-Lin Luo ◽

Darn-Horng Hsiao ◽

Chien-Ta Chen ◽

Ming-Du Cai

Keyword(s):

Sewage Sludge ◽

Silicon Dioxide ◽

Sewage Sludge Ash ◽

Subgrade Soil ◽

Cement Mixture ◽

Nano Silicon ◽

Sludge Ash ◽

Soft Subgrade

Download Full-text

The strength and microstructural behavior of lime stabilized subgrade soil in road construction

International Journal of Geotechnical Engineering ◽

10.1080/19386362.2019.1598623 ◽

2019 ◽

pp. 1-13 ◽

Cited By ~ 8

Author(s):

Subhradeep Dhar ◽

Monowar Hussain

Keyword(s):

Road Construction ◽

Subgrade Soil ◽

Microstructural Behavior

Download Full-text

Stabilization treatment of soft subgrade soil by sewage sludge ash and cement

Journal of Hazardous Materials ◽

10.1016/j.jhazmat.2008.05.060 ◽

2009 ◽

Vol 162 (1) ◽

pp. 321-327 ◽

Cited By ~ 110

Author(s):

Li Chen ◽

Deng-Fong Lin

Keyword(s):

Sewage Sludge ◽

Sewage Sludge Ash ◽

Stabilization Treatment ◽

Subgrade Soil ◽

Sludge Ash ◽

Soft Subgrade

Download Full-text

Assessment of burned coal shale properties based on cyclic load

E3S Web of Conferences ◽

10.1051/e3sconf/20183603001 ◽

2018 ◽

Vol 36 ◽

pp. 03001

Author(s):

Marcin Grygierek ◽

Piotr Kalisz ◽

Krzysztof Pacześniowski ◽

Andrzej Pytlik ◽

Magdalena Zięba

Keyword(s):

Cyclic Load ◽

Road Construction ◽

Cyclic Loads ◽

Preliminary Assessment ◽

Pilot Studies ◽

Subgrade Soil ◽

Road Surfaces ◽

The Subject ◽

Mechanically Stabilized ◽

Pavement Construction

Road surfaces that are subjected to cyclic loads generated by vehicle wheels must meet the requirements concerning the durability in the assumed period of use. The durability of the layered pavement construction systems depends on the value and frequency of the load as well as on the mechanical features of its individual layers. Layers of unbound, mechanically stabilized mixtures are a significant aspect of surfaces that are susceptible. Mixtures of this type can be applied both to the subgrade layers as well as to the bottom pavement layers, including the improved course. Considering the cyclic nature of the load on the surface of the entire system, mechanically stabilized layers are subject to continuous, but slow, densification during the period of use, which results in the formation of permanent deformations and so-called structural ruts. Post-mining waste is frequently used in road construction. which is the so-called burned shale that can be used for the bottom layers of the surface and layers of the improved subgrade (soil replacement). This material was the subject of the analysis. The evaluation was based mainly on the results of pilot studies covering cyclic loads of the layer/course made of the so-called red shale. The applied research method was aimed at preliminary assessment of its suitability for the assessment of the behaviour of the disintegrated medium under the conditions of test loads simulating the movement of vehicles.

Download Full-text

Impact of subgrade soils on pavement roughness

Canadian Geotechnical Journal ◽

10.1139/cgj-2015-0131 ◽

2016 ◽

Vol 53 (4) ◽

pp. 687-695

Author(s):

Michel Vaillancourt ◽

Daniel Perraton

Keyword(s):

Road Construction ◽

Soil Variability ◽

International Roughness Index ◽

Long Wavelength ◽

The Road ◽

Subgrade Soils ◽

Road Section ◽

Pavement Roughness ◽

Subgrade Soil ◽

The Impact

To highlight the impact of subgrade soil variability on the pseudo-profile and roughness at the end of road construction, a research program has been carried out at the Laboratoire sur les chaussées et matériaux bitumineux at École de technologie supérieure (ÉTS). The analysis is intended to highlight the variability of materials’ characteristics according to the longitudinal and vertical axes of the road. The proposed approach aims to calculate potential settlement variations through a global numerical simulation of a road section, in a bid to identify the expected pseudo-profile and to quantify the roughness quality by calculating the international roughness index (IRI). The proposed methodology was tested at a new road construction project in Québec. Here, the results of the simulations are compared to the details of the actual pseudo-profile obtained at the end of road construction for the project under study. It is shown, through the finite difference modeling of the mechanical behavior of the subgrade soil (FLAC calculation code), that the long wavelength pseudo-profile of the road at the end of construction can be determined, and that it is strongly influenced by subgrade soil variability. This article presents a second analysis carried out by Vaillancourt and Perraton in 2015 as part of a study of the impact of subgrade soils on pavement roughness.

Download Full-text

OPTIMUM CONSTRUCTION EQUIPMENT FLEETS FOR ROAD SURFACE OPERATIONS

Proceedings of International Structural Engineering and Construction ◽

10.14455/isec.res.2014.101 ◽

2014 ◽

Vol 1 (1) ◽

Author(s):

Tarek Gomaa ◽

Maged Georgy ◽

Moheeb Ibrahim

Keyword(s):

Genetic Algorithms ◽

Retaining Wall ◽

Discrete Event ◽

Road Construction ◽

Good Decision ◽

Actual Case ◽

Simulation Engine ◽

Subgrade Soil ◽

Hybrid Mechanism ◽

Surface Work

Poor subgrade soil condition which is very sensitive to moisture presents a construction challenge for all pavement engineers. One of the case histories which became a dilemma for the Azadegan freeway in Tehran is the presence of waste material in subgrade soil. This paper discusses the site investigation to gather some useful information about the principal causes of these problems and deals with some in-depth Laboratory tests which have been done in the soil and asphalt laboratory of Tehran municipality. The pavement condition index known as PCI has been calculated to address all the deteriorations and causes to make a good decision. After analyzing all the gathered data, several methods has been discussed, for example, deep mixing, short concrete piles, shredded tires, and injection. Finally based on the lack of facilities and budget shortage, a retaining wall with geogrids has been chosen for this very special case which is right now under traffic flow. The optimum selection of equipment fleets in surface work operations is a key element to the success of any road construction project. For years, computer simulations have been used to predict the performance of construction operations based on process flows and resources utilized. However, simulations in essence are not a resource optimization platform, since all possible resource combinations should be examined within the simulation process itself. This paper proposes a hybrid mechanism that integrates discrete event simulation and genetic algorithms to efficiently determine the best resource combination for the surface work operations in road construction. The paper employs genetic algorithms (GAs) for minimizing the total cost of surface work operations examined. A dynamic link utilizes a simulation engine, which models a road’s surface work operations, to calculate the fitness of the generated chromosomes. An actual case study is further utilized to illustrate the effectiveness and performance of this hybrid mechanism.

Download Full-text