N. Matasovic - Profile on Academia.edu (original) (raw)

Papers by N. Matasovic

Geotechnical Engineering Circular No. 3: Design Guidance: Geotechnical Earthquake Engineering for Highways, Volume I - Design Principles

This document has been written to provide information on how to apply principles of geotechnical ... more This document has been written to provide information on how to apply principles of geotechnical earthquake engineering to planning, design, and retrofit of highway facilities. Geotechnical earthquake engineering topics discussed in this document include: deterministic and probabilistic seismic hazard assessment; evaluation of design ground motions; seismic and site response analyses; evaluation of liquefaction potential and seismic settlements; seismic slope stability and deformation analyses; and seismic design of foundations and retaining structures. The document provides detailed information on basic principles and analyses, with reference to where detailed information on these analyses can be obtained. Design examples illustrating the principles and analyses described in this document are provided in Volume II - Design Examples, FHWA-SA-97-077.

iptv 환경에서의 지식구조 기반 방송프로그램 검색 및 다중 랭킹 기법

Korean Institute Of Information Technology, Nov 1, 2010

The performance of 22landfills in the Los Angeles area during the January 17, 1994 Northridge ear... more The performance of 22landfills in the Los Angeles area during the January 17, 1994 Northridge earthquake has been investigated. Observations of damage at these landfills indicate that the overall performance of solid waste landfills was encouraging. None of the surveyed landfills showed any signs of major damage. However, one geosynthetic-lined landfill experienced two tears in the geomembrane liner. Most landfills within 30 km of the zone of energy release experienced some form of cracking in the soil cover. Beyond approximately 40 km from the zone of energy release, little to no damage was observed.

Modulus Reduction and Damping Curves for Landfill Covers

Geotechnical Frontiers 2017, 2017

Unlike dynamic properties of municipal solid waste (MSW), the dynamic properties of engineered fi... more Unlike dynamic properties of municipal solid waste (MSW), the dynamic properties of engineered fill landfill covers at MSW and other landfill sites have not been extensively investigated. The two main reasons for the dearth of research on this topic are: (i) design engineers realize that modern landfill covers are relatively thin (on the order of 1.5 m, or less), and hence, their influence on the overall landfill response is assumed to be small; and (ii) there are readily available sets of dynamic soil properties of cohesive soils that could be assigned to landfill covers soils based upon the results of index testing. However, not all landfill covers are " thin, " and the readily available sets of dynamic soil properties may not be applicable for low-plasticity compacted and overconsolidated soils such as landfill covers. At many old landfills and Superfund sites, landfill cover thickness readily exceeds 5 m, and covers can be as thick as 10 to 15 m. These thicker covers may have significant influence on the overall response of landfills, and hence, careful evaluation of cover material properties is warranted. In this paper, results of in-situ nonlinear testing of landfill cover soils was used to develop modulus reduction curves. Shear strains in the cover soils ranging from 10-4 % to 2×10-2 % were induced by Vibroseis shakers. The material damping curves were estimated from modulus reduction curves by means of a nonlinear constitutive model, Masing rules, and engineering judgement. The modulus reduction and damping curves presented herein may be used for seismic design of landfill covers and other engineered fills constructed of soils of similar plasticity and with similar stiffness (i.e., shear wave velocity) and compaction characteristics.

Training Course in Geotechnical and Foundation Engineering - Nhi Course No. 13239 - Module 9. Geotechnical Earthquake Engineering - Reference Manual. Chapter 4 - Ground Motion Characterization; Chapter 8 - Liquefaction and Seismic Settlement

This manual was written to provide training on how to apply principles of geotechnical earthquake... more This manual was written to provide training on how to apply principles of geotechnical earthquake engineering to planning, design, and retrofit of highway facilities. Reproduced here are two chapters that deal with (1) ground motion characterization and (2) liquefaction and seismic settlement, respectively. These chapters supersede chapters 4 and 8 in the FHWA Circular on Geotechnical Earthquake Engineering for Highways, Volume 1.

Discussion of “Procedure for Estimating Shear-Induced Seismic Slope Displacement for Shallow Crustal Earthquakes” by Jonathan D. Bray and Jorge Macedo

Journal of Geotechnical and Geoenvironmental Engineering, 2021

Newmark Deformation Analysis with Degrading Yield Acceleration

This paper presents a seismic deformation analysis in which a degrading yield acceleration has be... more This paper presents a seismic deformation analysis in which a degrading yield acceleration has been implemented. The degradation of yield acceleration is modeled with a simple linear degradation model. Using a typical solid waste landfill composite cover configuration and actual interface shear strength testing results, the conservatism associated with seismic deformation analysis performed using the classical Newmark approach and a constant yield acceleration based upon residual and/or large deformation interface shear strength is investigated. The influence on permanent seismic deformation of the normal stress acting on the interface is also examined. Results indicate that Newmark seismic deformation analysis based solely on residual or large strain shear strength parameters is conservative.

Seismic Stability of Flysch Slopes

The article deals with various approaches to the analysis of seismic stability of flysch slopes i... more The article deals with various approaches to the analysis of seismic stability of flysch slopes in the adriatic coastal region. The existing data are systematized and the calculation models are designed to meet these specific requirements. It presents practical recommendations for the calculation, and analyzes two cases of landslide caused by an earthquake.

Landslide deposits are geologic features that show signs of movement ("failure") which occurred o... more Landslide deposits are geologic features that show signs of movement ("failure") which occurred outside the historical record. Unlike recent landslides, they do not show evidence of recent movement such as a defined head scarp, tension cracking, and/or bulging at the toe, but are identified by geomorphic evidence of past movement. Back analysis of landslides is a common technique used to assess shear strengths for design wherein a factor of safety (FS) equal to 1.0 is assumed along a pre-defined failure surface. However, as landslide deposits may no longer be "at the verge" of failure, a back analysis with an assumed FS equal to 1.0 may result in excessively conservative shear strength properties. Therefore, back analysis of landslide deposits should be performed assuming a FS greater than 1.0. As there is no consensus on how much higher than unity FS should be, values typically used in practice range between FS = 1.05 and 1.25 with little, if any, justification provided for FS selected. Consensus on seismic FS and/or calculated maximum permanent seismic displacement for use in back analysis is similarly lacking. In this paper we evaluate parameters that affect back analysis of landslide deposits and provide illustration using a recent case history from our practice.

Cyclic Characterization of Liquefiable Sands. Discussion and Closure

A discussion of a paper with the aforementioned title by Matasovic and Vucetic, published in this... more A discussion of a paper with the aforementioned title by Matasovic and Vucetic, published in this journal (Volume 119, Number 11, November 1993), is presented. The discussers note the advantage of using the modified Kondner and Zelasko hyperbolic model (MKZ) proposed by the authors. Discussion also focuses on two additional parameters of the MKZ model. Discussion is followed by closure from the authors.

Although the fact that sediments can amplify earthquake ground motion was recognized at least 100... more Although the fact that sediments can amplify earthquake ground motion was recognized at least 100 years ago (Milne, 1898), there has been a lingering uncertainty as to whether the degree of amplification varies with the level of input motion. This issue remains as one of the most important questions with respect to understanding and predicting earthquake ground motion. In accordance with the conservation of energy, seismicwave amplitudes generally increase in sediments due to lower densities and and/or lower seismic velocities. In addition, resonance effects can occur where abrupt impedance contrasts exist. If sediments were perfectly elastic, their response would be independent of incident-wave amplitudes. As with any real material, however, sediments begin to yield at some level of strain, and this violation of Hooke's law will give rise to a nonlinear response. The engineering community has long believed that sediment nonlinearity is significant. This perspective was based al...

Bulletin of the Seismological Society of America, 2001

We investigated the influence of depth to the half-space on evaluations of seismic response of a ... more We investigated the influence of depth to the half-space on evaluations of seismic response of a dry sandy soil deposit with thickness exceeding 100 m. Our investigation is based on the premise that the best estimate of surface response of such deposits is obtained using a statistically derived attenuation relationship, and the best estimate of other parameters required for geotechnical earthquake-engineering evaluations is obtained by calibrating the evaluated spectral characteristics of the site response using the best-estimate surface response. Results of our site-specific evaluations indicate that the preferred depth to the half-space does not coincide with the depth to bedrock, nor is the preferred depth uniquely defined in the seismic siteresponse analysis. We find that for a given accelerogram, the preferred depth to the half-space corresponds closely to the depth for which the peak horizontal ground acceleration (PHGA) predicted in the site-response analysis matches the median PHGA developed from the appropriate statistical attenuation relationship. Our results further indicate that the effect of the magnitude of the shear-wave velocity assigned to the half-space is minor in comparison with depth to the half-space.

Soil Dynamics and …, 2006

In areas of high seismicity, seismic stability often controls hazardous and solid waste landfill ... more In areas of high seismicity, seismic stability often controls hazardous and solid waste landfill closure design. The undrained shear strength (Su) of the waste mass is fundamental to seismic slope stability analyses. The value of Su for hazardous waste fill is often difficult to ...

One-dimensional nonlinear ground response analyses provide a more accurate characterization of th... more One-dimensional nonlinear ground response analyses provide a more accurate characterization of the true nonlinear soil behavior than equivalent-linear procedures, but the application of nonlinear codes in practice has been limited, which results in part from poorly documented and unclear parameter selection and code usage protocols. In this article, exact ͑linear frequency-domain͒ solutions for body wave propagation through an elastic medium are used to establish guidelines for two issues that have long been a source of confusion for users of nonlinear codes. The first issue concerns the specification of input motion as "outcropping" ͑i.e., equivalent free-surface motions͒ versus "within" ͑i.e., motions occurring at depth within a site profile͒. When the input motion is recorded at the ground surface ͑e.g., at a rock site͒, the full outcropping ͑rock͒ motion should be used along with an elastic base having a stiffness appropriate for the underlying rock. The second issue concerns the specification of viscous damping ͑used in most nonlinear codes͒ or small-strain hysteretic damping ͑used by one code considered herein͒, either of which is needed for a stable solution at small strains. For a viscous damping formulation, critical issues include the target value of the viscous damping ratio and the frequencies for which the viscous damping produced by the model matches the target. For codes that allow the use of "full" Rayleigh damping ͑which has two target frequencies͒, the target damping ratio should be the small-strain material damping, and the target frequencies should be established through a process by which linear time domain and frequency domain solutions are matched. As a first approximation, the first-mode site frequency and five times that frequency can be used. For codes with different damping models, alternative recommendations are developed.

Development of a numerical model for performance-based design of geosynthetic liner systems

Geotextiles and Geomembranes

One-dimensional seismic ground response analyses are often performed using equivalent-linear proc... more One-dimensional seismic ground response analyses are often performed using equivalent-linear procedures, which require few, generally well-known parameters (shear wave velocity, modulus reduction and damping versus shear strain, and soil density). Nonlinear analyses provide a more robust characterization of the true nonlinear soil behavior, but their implementation in practice has been limited, which is principally a result of poorly documented and unclear parameter selection and code usage protocols. Moreover, the benefits and potentials of nonlinear analysis relative to equivalent linear are not well defined. In this paper, we present preliminary results of a "benchmarking study" of nonlinear ground response analysis procedures. Key issues that are discussed include: (1) the use of a simple curve-fitting parameter to describe the shape of the backbone curve, avoiding the need to determine dynamic shear strength (which is often unavailable);

Geo-Frontiers 2011, 2011

Two-dimensional (2-D) non-linear time-domain analyses of the tensile forces and strains induced i... more Two-dimensional (2-D) non-linear time-domain analyses of the tensile forces and strains induced in the geosynthetic liner system of a solid waste landfill by seismic loading were conducted using a model that allows for relative displacement (slip) at the interfaces of the liner system. The analyses suggest that tensile strains and forces induced in the liner system by seismic loading will be within allowable values if the difference in interface friction angle between the top and bottom of the liner is relatively small. While the deformation at the crest of the side slope from the non-linear analyses were similar to the deformations calculated in a conventional 1-D decoupled analysis, the deformations at the toe of a canyon-type landfill calculated in the 2-D non-linear analysis was significantly greater than calculated in the 1-D decoupled analysis. The analyses reported herein were for two simplified landfill geometries and only employed one earthquake time history and one set of interface strengths. Additional analyses are required to determine if these results are representative of landfill response or are an artifact of the landfill geometry, interface strengths, and time history used in these analyses.

In plane-behavior of geosynthetic barrier layers subject to cyclic loading