Time filter

Source Type

Indianapolis, IN, United States

Jung C.,Samsung | Bobet A.,Purdue University | Siddiki N.Z.,Office of Geotechnical Engineering
Transportation Research Record | Year: 2011

An experimental investigation proposed a simple, practical method to identify marl soils in the laboratory and to classify the soils. The percentage of calcium carbonate (CaCO3) of the soil was determined with three methods: (a) thermogravimetric analysis (TGA), (b) sequential loss on ignition (LOI), and (c) chemical reaction following ASTM C25. The sequential LOI test has the advantage that both organic and CaCO3 content of the soil can be determined with a conventional furnace. X-ray diffraction, pH, and Atterberg limits tests were also conducted. The percentage of CaCO3 determined from the sequential LOI tests agreed well with those from the TGA tests and from the chemical tests. No correlation was found between the percentage of CaCO3 and organic content in the soil. As the organic content of the soil increases, the liquid limit increases and the plasticity of the soil increases. As the CaCO3 content of the soil increases, the liquid limit of the soil decreases and the soil becomes less plastic. The geotechnical engineering properties of marl soils depend on organic content and CaCO 3 content, and so the soils should be classified according to both organic content and CaCO3 content.

Jung C.,Samsung | Jung C.,Purdue University | Jung S.,Purdue University | Siddiki N.Z.,Office of Geotechnical Engineering | Bobet A.,Purdue University
International Journal of Pavement Engineering | Year: 2013

A field investigation was performed immediately after the construction of a subgrade treated with 5% lime kiln dust (LKD) to determine the degree of uniformity and quality achieved using current construction techniques. A 280-m long section of a road was chosen for the field tests. The first 140 m was treated with LKD over a target thickness of 41 cm (16 inches), which is the current standard practice in Indiana. The second 140 m was treated with a reduced target thickness of 36-cm (14 inches). For the thicker, 41-cm treated subgrade, the increase in california bearing ratio (CBR) with respect to that of the untreated soil at the site was around 100%, as average, while for the thinner, 36-cm treated subgrade it was about 350%. All field and laboratory test results showed consistently better and more uniform results for the 36-cm thick treated subgrade than for the 41-cm thick treated subgrade. © 2013 Copyright Taylor and Francis Group, LLC.

Lee W.,Purdue University | Kim D.,Chosun University | Salgado R.,Purdue University | Zaheer M.,Office of Geotechnical Engineering
Soils and Foundations | Year: 2010

The load capacity of driven piles has been reported to sometimes increase or decrease with time after pile installation. An increase in pile capacity with time is known as setup, whereas a decrease in capacity is referred to as relaxation. In this paper, we review the current understanding of pile setup and discuss how to account for it in design. A total of forty-three dynamic tests were conducted over a period of five months on four H piles and four closed-ended pipe piles driven into layered soil. Test results show that the amount and rate of pile setup are quite different from those observed in other studies. Empirical formulas for predicting setup proposed by several researchers were compared with observations. Of the empirical formulas considered, the Svinkin (1996) lower-bound method predicted the rate of setup on these piles driven in layered soil relatively well. Additionally, some theoretical methods for prediction of evolution of static pile bearing capacity with time were tested against the dynamic pile test results. The bearing capacity from these theoretical methods was found to correspond to approximately 2 times the capacity measured at the end of initial driving by a dynamic test.

Jung C.,Samsung | Jung C.,Purdue University | Bobet A.,Purdue University | Siddiki N.Z.,Office of Geotechnical Engineering | Kim D.,Chosun University
Journal of Materials in Civil Engineering | Year: 2011

An extensive field investigation was carried out to determine the properties of subgrade soils treated with lime in pavements that had been in service for at least five years. Six sites were selected for the field tests. At each site, standard penetration test (SPT), dynamic cone penetration test (DCPT), and falling weight deflectometer (FWD) tests were performed to evaluate the in situ stiffness and/or strength properties of the lime-treated subgrade. In addition, laboratory tests on soil samples taken from the SPT spoon were done to obtain index properties. The long-term performance of the subgrade was evaluated by comparing the soil indexes and stiffness and/or strength properties of the lime-treated subgrade soil with those of the natural soil. In addition, pH, X-ray diffraction (XRD), and thermogravimetric analysis (TGA) tests were conducted for both lime-treated and natural soils. The field and laboratory investigation showed that (1) the lime remains in the soil even after 11 years of service of the road; (2) the addition of lime decreases the plasticity of the soil and increases its California bearing ration (CBR); and (3) the construction quality determined from the field tests was highly variable. © 2011 American Society of Civil Engineers.

Discover hidden collaborations