Loading patterns in varved Pleistocene sediment in the NYC area

1991

In 1976 James Parsons of Mueser Rutledge Consulting Engineers described the engineering characteristics of the varved silts and clays found in the New York City area. Over the years MRCE has conducted extensive testing of the local soils, including work for numerous

2010

In 2006 a boring investigation was conducted at a site in northwest Brooklyn. The project is located along the east side of the East River bounded by N. 5th Street, N. 7th Street, and Kent Avenue. The glacial deposits in the New York City area generally have similar characteristics. They may have the same grain size mix but different colors, or the same color and constituents with slight variations in the grain size range. The borings at this site, however, revealed a complex sequence of strata that included a couple of units that were unusual and distinctive, not typical of anything else in the area. The lead author has spent over the past 20 years with Mueser Rutledge Consulting Engineers sampling, reclassifying and testing soil and rock in the New York City area. In recent years projects in northwest Brooklyn have encountered some of the unusual strata. This particular site brings the distinctive units together in a way that begins to show how they are inter-related. The nature o...

This standard is issued under the fixed designation D 2435; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.

2004

A thorough understanding of the local geologic and tectonic environment, the seismological history as well as very detailed site specific geotechnical and geophysical data are essential to the proper prediction of local site effects and seismic design in New York City (NYC). The site response in the NYC metropolitan area is affected by the widely varying geologic conditions encountered in the five boroughs. Along the spine of Manhattan Island rock extends well above sea level at the northern reaches, and falls to depths in excess of 250 m at the barrier islands at the southern extremities of NYC. Large areas in the City have been filled to cover soft sediments and marshes to accommodate the need for building space, such as the present area of Chinatown that is built on fills that have replaced a large lake known as Collect Pond; the World Fairs site in Long Island Sound Embayment in Flushing, Queens, and the ground on which JFK Airport is constructed by placing hydraulic sand fill in the south shore of Brooklyn. The highly variable geologic conditions, along with the lack of strong ground motion recordings create uncertainty in predicting site response. This paper will present an overall review of the geological and seismological characteristics of the NYC metropolitan area and will examine how current, applicable codes deal with predicting soil amplification and evaluating liquefaction hazard. Issues of concern not covered in codes, such as the effect of high impedance contrast between hard bedrock and soft soil and the response of soft-high-plasticity organic clays and silts will be examined using typical NYC soil profiles and state-of-practice design motions and hazard levels.

Frontiers of Architecture and Civil Engineering in China, 2008

The main method for the determination of consolidation parameters in Flanders (Belgium) is still the incremental loading test (IL test). This method can take up to several weeks for some typical Flemish overconsolidated (OC) clays. In theory, the same relationship between settlement and vertical stress can be obtained by performing a constant rate of strain test (CRS test). The main advantages of a CRS test are that the data is continuous and that the test can often be completed considerably faster than an IL test. In this paper, results of both IL and CRS tests on two undisturbed stiff OC clay samples of the same geological formation (Maldegem formation deposited during the Paleogene period) were compared. CRS tests were performed based on ASTM D4186, but constant stress stages were controlled using effective vertical stress instead of total vertical stress as most important adjustment to the standard. In addition, special attention was paid to the development of initial swell pressure and selecting an appropriate rate of strain for this clay with a very high plasticity. Similar values for compressibility and hydraulic conductivity were found using both IL and CRS test results. As the duration of a CRS test on this clay with low hydraulic conductivity can also take up to a few weeks, the time saving aspect of the test was found to be limited for the stiff OC clay tested. The uncertainty in estimating the pre-consolidation pressure and swell pressure was smaller using the continuous CRS test results.

2014

The purpose of this study is to determine if grain size modes already present in weathered bedrock sediments can be retained and inherited in derived, or processed sediments. To test this theory, weathered bedrock sediment, as well as Cretaceous aged sands and silts, Glacial sands and silts, Loess-like silt sediment, and glacially transported granitic gneisses were collected and analyzed for grain size. This study is based on the implicit assumption that grain size modes are indicative only of process, and are not reflective of modes present in the parent material of the sediment. A distinct pattern of grain size modes at about 20μm, and 400μm in most if not all pebbly-loess samples from various sites in Suffolk County and modes of 20μm, 80 μm, and 400μm from till and outwash sands on the Stony Brook campus (Zhong, 2002, Kundic, 2005, A. Olaofe, personal communication, 2012 and T. Clare, personal communication 2013). This lead to investigating if these modes are found in other sediment samples. Glacial samples were collected from iv Centereach, Long Island, New York, and also were found to display the same pattern of modes seen at Stony Brook. Investigations of Cretaceous sediments from Caumsett State Park also display the same pattern of modes at about 20μm, 80 μm, and 400μm. Analysis of weathered bedrock from Brookhaven, and mechanically crushed rocks, typical of those believed to be the parent rock of the glacial and loessic sediments was also conducted, showing the same mode pattern. Additionally, petrographic analysis of a sample of bedrock, similar to the weathered bedrock in our study, showed silt sized grains already present in the bedrock. Analysis of possible machine bias towards certain modes was also conducted. All of the samples were analyzed with a Malvern Mastersizer 2000. It appears that the modes seen in sedimentary samples of loess, glacial sands, glacial till, cretaceous sands, weathered bedrock, and manufactured bedrock all show polymodial pattern of modes at about 10.00μm-20.00μm, 100.00μm-200.00μm, and 400.00μm-500.00μm may be inherent in the parent bedrock of the sedimentary material. Furthermore, analysis with a Sediment Grain Size Analyzer program shows that the high rate of 80 micron modes seen in the Mastersizer results are possibly due to a combination of modes seen between 90 microns and 100 microns, regardless of the type sediment. In conclusion, we can state that grain size modes found in weathered bedrock on Long Island, New York, can be retained as common modes in derived sediments, such as Cretaceous materials, and glacial materials, such that process is not the only determination of the sediment mode characteristics. In addition, we can also state that silt sized particles can in fact be created without the aid of glacial grinding, as seen in the thin section analysis. v Table of Contents Introduction: …………………………………………………………………………………...p.1 Geologic Background………………………………………………………………….p.2 Stony Brook University…………………………...…………………………...p.3 Centereach……………………………………………………………………...p.4 Caumsett State Park………...………………………………………………….p.4 Brookhaven………...…………………………………………………………..p.5 Methods: ……………………………………………………………………..………………..p.7 Sampling Protocols…………………………………………………………………….p.7 Stony Brook University………………………………………………………..p.7 Centereach……………………………………………………………………...p.8 Caumsett State Park……………………………………………………………p.9 Brookhaven…………………………………………………………………….p.9 Mastersizer Methods…………………………………………………………………...p.9 Grain Analysis Software……………………………………………………………...p.11 Whole Rock Crushing Experiments…………………………………………………..p.12 Results: ……………………………………………………………………………………….p.15 Stony Brook University………………………………………………………………p.15 Centereach…………………………………………………………………………….p.16 Caumsett State Park…………………………………………………………………..p.18 Brookhaven Sediments (Above Bedrock)……………………………………………p.19 Brookhaven Weathered Bedrock……………………………………………………..p.20 Whole Rock Grinding Experiments…………………………………………………..p.22 vi Discussion: ..………………………………………………………………………………….p.35 Pebbly-Loess and Glacial Sediments…………………………………………………p.37 Whole Rock Samples…………………………………………………………………p.39 Brookhaven Weathered Bedrock……………………………………………………..p.42 Explanation of Silt in Bedrock………………………………………………………..p.42 Cretaceous…………………………………………………………………………….p.45

2006

2020

Working on Janbu’s proposals, for the assessment of one-dimensional consolidation settlement for saturated soils, and on Boulanger and Idriss soil behaviour index to assess liquefaction susceptibility, it appears that soil can be classify in three families, having each their own set of relationships. First, it is interesting to analyse if the 400μm.D part is scattered in the 0.400μm one, or if the 400μm.D grains are in contact with each other’s, D being the smaller dimension of the bigger grains. Secondly, is introduced and analysed the interest of blue methylene values measurements. And then, having well characterised soil identification (gradation curve, blue methylene test, Atterberg limit, water content) is detailed how soils behave for each family, showing the complementary interest of cone penetration tests with induced pore water pressure measurement (CPT’u) and Menard pressuremeter test (PMT) for the first two categories. RESUME : Travaillant sur les propositions de Janbu po...

Japanese Geotechnical Society Special Publication, 2016

The consolidation characteristics of soft sediment dredges from Newark bay area, New Jersey, is investigated through seepage induced consolidation test device. In this paper the seepage induced consolidation test device was constructed and used to evaluate compressibility and permeability behavior of fine, low density sediments. Conventional consolidation tests usually involve restrictive assumptions on the amount of strain, hydraulic conductivity and coefficient of consolidation which makes them impractical dealing with soft sediments at low stress levels. The soft nature of dredged material and mine tailings hinders using conventional consolidometers for testing purposes. It is difficult to test the compressibility and permeability of these types of sediments at low effective stresses. Therefore a consolidation cell, based on seepage force was constructed based on seepage induced consolidation tester (SICT) at University of Colorado at Boulder and the consolidation characteristics of soft sediments dredged from seabed is investigated. Results of this research program showed that this method of testing is applicable to the soft sediment consolidation testing and provides reliable and repeatable results.