Mapping NEHRP VS30 Site Classes

2005 ◽  
Vol 21 (2) ◽  
pp. 353-370 ◽  
Author(s):  
Thomas L. Holzer ◽  
Amy C. Padovani ◽  
Michael J. Bennett ◽  
Thomas E. Noce ◽  
John C. Tinsley
Keyword(s):  
San Francisco ◽  
Site Amplification ◽  
Cone Penetration ◽  
Site Class ◽  
Mean Values ◽  
Shear Wave Velocities ◽  
Class D ◽  
Geologic Maps ◽  
Definition Of ◽  
Site Classes

Site-amplification potential in a 140-km2 area on the eastern shore of San Francisco Bay, California, was mapped with data from 210 seismic cone penetration test (SCPT) soundings. NEHRP VS30 values were computed on a 50-m grid by both taking into account the thickness and using mean values of locally measured shear-wave velocities of shallow geologic units. The resulting map of NEHRP VS30 site classes differs from other published maps that (1) do not include unit thickness and (2) are based on regional compilations of velocity. Although much of the area in the new map is now classified as NEHRP Site Class D, the velocities of the geologic deposits within this area are either near the upper or lower VS30 boundary of Class D. If maps of NEHRP site classes are to be based on geologic maps, velocity distributions of geologic units may need to be considered in the definition of VS30 boundaries of NEHRP site classes.

New Site Coefficients and Site Classification System Used in Recent Building Seismic Code Provisions

2000 ◽  
Vol 16 (1) ◽  
pp. 41-67 ◽  
Author(s):  
R. Dobry ◽  
R. D. Borcherdt ◽  
C. B. Crouse ◽  
I. M. Idriss ◽  
W. B. Joyner ◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Classification System ◽  
Site Amplification ◽  
Site Classification ◽  
Site Class ◽  
Site Classes ◽  
Code Provisions

Recent code provisions for buildings and other structures (1994 and 1997 NEHRP Provisions, 1997 UBC) have adopted new site amplification factors and a new procedure for site classification. Two amplitude-dependent site amplification factors are specified: Fa for short periods and Fv for longer periods. Previous codes included only a long period factor S and did not provide for a short period amplification factor. The new site classification system is based on definitions of five site classes in terms of a representative average shear wave velocity to a depth of 30 m (V¯s). This definition permits sites to be classified unambiguously. When the shear wave velocity is not available, other soil properties such as standard penetration resistance or undrained shear strength can be used. The new site classes denoted by letters A - E, replace site classes in previous codes denoted by S1 - S4. Site classes A and B correspond to hard rock and rock, Site Class C corresponds to soft rock and very stiff / very dense soil, and Site Classes D and E correspond to stiff soil and soft soil. A sixth site class, F, is defined for soils requiring site-specific evaluations. Both Fa and Fv are functions of the site class, and also of the level of seismic hazard on rock, defined by parameters such as Aa and Av ( 1994 NEHRP Provisions), Ss and Sl ( 1997 NEHRP Provisions) or Z ( 1997 UBC). The values of Fa and Fv decrease as the seismic hazard on rock increases due to soil nonlinearity. The greatest impact of the new factors Fa and Fv as compared with the old S factors occurs in areas of low-to-medium seismic hazard. This paper summarizes the new site provisions, explains the basis for them, and discusses ongoing studies of site amplification in recent earthquakes that may influence future code developments.

scholarly journals A study on sensitivity of seismic site amplification factors to site conditions for bridges

2018 ◽  
Vol 51 (4) ◽  
pp. 197-211
Author(s):  
Muhammad Tariq A. Chaudhary
Keyword(s):  
Seismic Design ◽  
Site Amplification ◽  
Site Conditions ◽  
Design Codes ◽  
Design Code ◽  
Bridge Design ◽  
Site Class ◽  
Vibration Period ◽  
Amplification Factors ◽  
Site Classes

Seismic site amplification factors and seismic design spectra for bridges are influenced by site conditions that include geotechnical properties of soil strata as well as the geological setting. All modern seismic design codes recognize this fact and assign design spectral shapes based on site conditions or specify a 2-parameter model with site amplification factors as a function of site class, seismic intensity and vibration period (short and long). Design codes made a number of assumptions related to the site conditions while specifying the values of short (Fa) and long period (Fv) site amplification factors. Making these assumptions was necessary due to vast variation in site properties and limited availability of actual strong motion records on all site conditions and seismic setting in a region. This paper conducted a sensitivity analysis for site amplification factors for site classes C and D in the AASHTO bridge design code by performing a 1-D site response analysis in which values of site parameters like strata depth, travel-time averaged shear wave velocity in the top 30 m strata (Vs30), plasticity index (PI), impedance contrast ratio (ICR) and intensity of seismic ground motion were varied. The results were analyzed to identify the site parameters that impacted Fa and Fv values for site classes C and D. The computed Fa and Fv values were compared with the corresponding values in the AASHTO bridge design code and it was found that the code-based Fa and Fv values were generally underestimated and overestimated respectively.

scholarly journals Kelas Situs Tanah Kota Banda Aceh Berdasarkan Nilai Periode Dominan Mikrotremor

2017 ◽  
Vol 8 (3) ◽  
pp. 127
Author(s):  
Cecep Sulaeman ◽  
Akhmad Solikhin
Keyword(s):  
Amplification Factor ◽  
Soft Soil ◽  
Site Amplification ◽  
Data Logger ◽  
Site Class ◽  
Class D ◽  
Dominant Period ◽  
Hard Soil ◽  
Factor Maps ◽  
Banda Aceh

ABSTRAKPengukuran mikrotremor di Kota Banda Aceh telah dilakukan untuk mengetahui periode dominan dan nilai faktoramplifikasi guncangan gempa bumi. Pengukuran dilakukan pada 92 titik ukur memakai seismometer 3 komponenmodel Lennartz LE-3D berperiode natural 5 detik dan perekam digital model SARA SL-06 24 bit. Peta mikrotremorKota Banda Aceh terdiri atas periode dominan dan H/V amplifikasi. Periode dominan Kota Banda Aceh menunjukkanterdapat tiga kelas situs tanah yaitu : kelas situs C (tanah keras) dengan nilai periode dominan 0,2 detik < T ≤ 0,4detik, kelas D (tanah kaku) dengan nilai periode dominan antara 0,4 detik hingga 0,6 detik, dan kelas E (tanah lunak)dengan nilai periode dominan di atas 0,6 detik. Kelas situs D dan E menyebar hampir ke semua kecamatan sementarakelas situs C hanya terdapat di Kutaraja. Nilai H/V amplifikasi Kota Banda Aceh bervariasi antara 1,98 hingga 5,88.Kata kunci : periode dominan, ampilifikasi, kelas situs tanah.ABSTRACTMicrotremor measurement was conducted to obtain dominant period and site amplification factor of Banda AcehCity. The measurements were carried out in 92 sites in the city using 3-component-seismometer Lennartz LE-3D withnatural period 5 s and data logger model SARA SL-06 24 bit. The microtremor map of Banda Aceh City consists ofdominant period and H/V amplification factor maps. The dominant period of Banda Aceh City consisting of three siteclasses are C (hard soil) with dominant period 0.2 s < T ≤ 0.4 s, D (stiff soil) with dominant period between 0.4 sto 0.6 s, and E (soft soil) with dominant period greater than 0.6 s. Site class D and E areas stretch out almost in allsubdistricts, while C class is only in Kutaraja. The H/V amplification value of Banda Aceh city varies between 1.98and 5.88.Keywords : dominant period, amplification, site class.

NEHRP Site Amplification Factors and the NGA Relationships

2010 ◽  
Vol 26 (2) ◽  
pp. 583-593 ◽  
Author(s):  
Yin-Nan Huang ◽  
Andrew S. Whittaker ◽  
Nicolas Luco
Keyword(s):  
Reference Site ◽  
Functional Form ◽  
Strong Motion ◽  
Site Amplification ◽  
Large Database ◽  
Site Condition ◽  
Site Class ◽  
Amplification Factors ◽  
Crustal Earthquakes ◽  
Site Classes

The Next Generation Attenuation (NGA) relationships were developed using a large database of strong motion recordings of shallow crustal earthquakes. The functional form of the relationships provides an opportunity to assess and update if necessary the site class coefficients provided in the NEHRP Provisions and ASCE-7. Site amplification factors estimated using the Boore and Atkinson, Campbell and Bozorgnia, and Chiou and Youngs NGA relationships are computed and averaged for a combination of magnitude, distance, faulting type and period and for NEHRP/ASCE-7 Site Classes B, C, D and E and boundaries A/B, B/C, C/D and D/E. The average NGA site amplification factors show a clear dependency on period for V S30 smaller than 270 m/s and are substantially greater than the current NEHRP site class coefficients in some cases. The use of the NEHRP/ASCE-7 site class coefficients and spectral demands for the reference site condition computed using the NGA relationships may produce erroneous results. A family of site class coefficients is proposed to address these issues in a format suitable for inclusion in the NEHRP Provisions and ASCE-7.

scholarly journals Surface and Underground Geomechanical Characterization of an Area Affected by Instability Phenomena in Zaruma Mining Zone (Ecuador)

2021 ◽  
Vol 13 (6) ◽  
pp. 3272
Author(s):  
Paúl Carrión-Mero ◽  
Maribel Aguilar-Aguilar ◽  
Fernando Morante-Carballo ◽  
María José Domínguez-Cuesta ◽  
Cristhian Sánchez-Padilla ◽  
...  
Keyword(s):  
Mass Movement ◽  
Mining Activity ◽  
Mining District ◽  
Mean Values ◽  
Surface Areas ◽  
Definition Of ◽  
Action Measures ◽  
Geomechanical Characterization ◽  
The City

In the last decade, in the mining district of Zaruma-Portovelo, there has been significant land subsidence related to uncontrolled mining activity. The purpose of this work was to carry out a surface and underground geomechanical characterization of a mining sector north of the city of Zaruma that allows the definition of potentially unstable areas susceptible to the mass movement. The methodology used consists of the following stages: (i) compilation of previous studies; (ii) surface and underground characterization of rocky material to establish its susceptibility to mass movement; (iii) interpretation of results; and (iv) proposal of action measures. Among the most relevant results, it stands out that 26.1% of the 23 stations characterized on the surface present conditions that vary from potentially unstable to unstable. In underground galleries, the studied mean values of the 17 stations indicate that the rock has a medium to good quality, representing a medium susceptibility to gallery destabilization. The results obtained for the surface areas (depths up to 50 m, where altered materials predominate) and the underground areas (depths > 50 m, where the alterations are specific) can be used to identify the areas with a more significant potential for instability. For both cases, it has been possible to define specific monitoring, control, and planning actions for sensitive areas.

scholarly journals A numerical fit of analytical to simulated density profiles in dark matter haloes

2005 ◽  
pp. 13-32 ◽  
Author(s):  
R. Caimmi ◽  
C. Marmo ◽  
T. Valentinuzzi
Keyword(s):  
High Resolution ◽  
Density Profile ◽  
Geometrical Parameters ◽  
Density Profiles ◽  
Mean Values ◽  
Geometrical Properties ◽  
Best Fitting ◽  
Definition Of ◽  
Additional Support ◽  
Open Question

Analytical and geometrical properties of generalized power-law (GPL) density profiles are investigated in detail. In particular, a one-to-one correspondence is found between mathematical parameters (a scaling radius, r0, a scaling density, ?0, and three exponents, ?, ?, ?), and geometrical parameters (the coordinates of the intersection of the asymptotes, xC, yC, and three vertical intercepts, b, b?, b?, related to the curve and the asymptotes, respectively): (r0,?0,?,?,?) ? (xC,yC,b,b?,b?). Then GPL density profiles are compared with simulated dark haloes (SDH) density profiles, and nonlinear least-absolute values and least-squares fits involving the above mentioned five parameters (RFSM5 method) are prescribed. More specifically, the sum of absolute values or squares of absolute logarithmic residuals, Ri=log?SDH(ri) ? log?GPL(ri), is evaluated on 10 points making a 5dimension hypergrid, through a few iterations. The size is progressively reduced around a fiducial minimum, and superpositions on nodes of earlier hypergrids are avoided. An application is made to a sample of 17 SDHs on the scale of cluster of galaxies, within a flat ?CDM cosmological model (Rasia et al. 2004). In dealing with the mean SDH density profile, a virial radius, Rvir, averaged over the whole sample, is assigned, which allows the calculation of the remaining parameters. Using a RFSM5 method provides a better fit with respect to other methods. The geometrical parameters, averaged over the whole sample of best fitting GPL density profiles, yield (?, ?, ?) ? (0.6,3.1,1.0), to be compared with (?, ?, ?) = (1,3,1), i.e. the NFW density profile (Navarro et al. 1995, 1996, 1997), (?, ?, ?) = (1.5,3, 1.5) (Moore et al. 1998, 1999), (?, ?, ?) = (1,2.5,1) (Rasia et al. 2004); and, in addition, ? ? 1.5 (Hiotelis 2003), deduced from the application of a RFSM5 method, but using a different definition of scaled radius, or concentration; and ? ? 1.21.3 deduced from more recent high-resolution simulations (Diemand et al. 2004, Reed et al. 2005). No evident correlation is found between SDH dynamical state (relaxed or merging) and asymptotic inner slope of the fitting logarithmic density profile or (for SDH comparable virial masses) scaled radius. Mean values and standard deviations of some parameters are calculated, and in particular the decimal logarithm of the scaled radius, ?vir, reads < log?vir >= 0.74 and ?slog?vir = 0.150.17, consistent with previous results related to NFW density profiles. It provides additional support to the idea, that NFW density profiles may be considered as a convenient way to parametrize SDH density profiles, without implying that it necessarily produces the best possible fit (Bullock et al. 2001). A certain degree of degeneracy is found in fitting GPL to SDH density profiles. If it is intrinsic to the RFSM5 method or it could be reduced by the next generation of high-resolution simulations, still remains an open question. .

scholarly journals Perceptions of Health Status in Multiple Sclerosis Patients and Their Doctors

2013 ◽  
Vol 40 (2) ◽  
pp. 210-218 ◽  
Author(s):  
Marcelo Kremenchutzky ◽  
Len Walt
Keyword(s):  
Multiple Sclerosis ◽  
Health Status ◽  
Bodily Pain ◽  
Kappa Statistic ◽  
Patient Perceptions ◽  
Mean Values ◽  
Health Domains ◽  
Important Health ◽  
Definition Of ◽  
Multiple Sclerosis Patients

Objective:To compare neurologist and patient perceptions of multiple sclerosis (MS)-related health status.Methods:MS patients (n=99) were recruited from six sites in Canada. Following a consultation with their neurologist, patients estimated their relapse frequency, rated their general health and quality of life (QoL), reviewed descriptions of eight health domains and selected the three most important, and completed a utility assessment using the standard gamble (SG). Concurrently, neurologists independently used the same instruments to rate their patients' health status. Assessments were compared on the basis of paired mean values of both groups and the degree of exact agreement quantified by intraclass coefficient (ICC) and kappa analyses, which yield values of 1.0 with 100% agreement.Results:There were significant differences (p<0.001) between patient and neurologist ratings for relapses in the last year (0.86 vs. 0.4, respectively), QoL (61.2 vs. 69.7 (maximum score = 100) and utility (0.864 vs. 0.971); ICC analysis revealed moderate to poor levels of agreement (0.56 for QoL to 0.03 for SG). There was little concordance in identification of important health domain and the only significant associations were in bodily pain and social functioning (kappa statistic = 0.24, p = 0.026 for both). Neurologists identified physical functioning domains as important, while patients placed more emphasis on mental health domains.Conclusions:Discrepancies between neurologist and patient perceptions of MS were observed. The study identifies a need to educate neurologists on the recognition of MS health domains that are important in the definition of patient QoL.

scholarly journals Development of psychological culture as a condition for effective personal self-actualization

2021 ◽  
Vol 122 ◽  
pp. 06001
Author(s):  
Galina Veniaminovna Sorokoumova ◽  
Tatiana Evgenevna Egorova ◽  
Olga Alekseevna Kostina ◽  
Svetlana Alekseevna Tikhonina ◽  
Grigorii Aleksandrovich Nikonov
Keyword(s):  
Rank Test ◽  
Training Methods ◽  
Moral Value ◽  
Mean Values ◽  
Formative Stage ◽  
Sound Therapy ◽  
Self Actualization ◽  
Signed Rank Test ◽  
Definition Of ◽  
Culture Development

The article examines the problem of personal self-actualization through the lens of psychological culture, approaches to the definition of psychological culture are presented, and the struсture of psychological culture and ways of its development are considered. The article reviews the methods that go beyond the activities of educational institutions: volunteer work, social and psychological training, methods of expressive psychotherapy (art therapy, movement and dance therapy, music therapy, and neuroacoustics – sound therapy), etc. Based on the ecopsychological approach, psychological culture is suggested to be defined as a set of actions to create optimal internal conditions for the development and self-modification of the personality, to cultivate a subject of activity capable of taking action, coordinating its activity with the natural, social, spiritual. and moral (value and meaning) foundations of interaction with the surrounding world and oneself. The article analyses the results of the study of the effect of psychological culture on the development of self-actualization of teachers in refresher courses. At the ascertaining and control stages, the level of self-actualization of teachers in the control and experimental groups was assessed using the Self-Actualization Test (SAT). At the formative stage, teachers of the experimental group participated in a program for the development of psychological culture. The ecopsychological approach with principles developed on its basis and the stage-by-stage nature of the development of new mental functions serves as a basis for constructing the technology for implementing the program for the development of psychological culture in specialists. The reliability of the test results and differences in the mean values are assessed using the Wilcoxon signed-rank test. The formative program shows the effective influence of psychological culture development on personal self-actualization.

Pathways of Microvascular Permeability in the Synovium of Normal and Diseased Human Knees

2011 ◽  
Vol 38 (12) ◽  
pp. 2635-2642 ◽  
Author(s):  
PETER A. SIMKIN ◽  
JOHN E. BASSETT
Keyword(s):  
Plasma Proteins ◽  
Gel Filtration ◽  
Joint Disease ◽  
Normal Flow ◽  
Microvascular Endothelium ◽  
Mean Values ◽  
Pore Model ◽  
Small Pore ◽  
Definition Of ◽  
Molecular Radius

Objective.Our study uses the entire proteomes of serum and synovial fluid (SF) to characterize the avenues of microvascular egress of plasma proteins, and quantifies that traffic in normal and diseased human knees.Methods.Paired aliquots of serum and SF were collected from 17 knees of 11 subjects who died without evident joint disease and 16 patients with clinical effusions, fractionated by gel filtration chromatography and analyzed as continuous plots of the SF/serum concentration ratio versus molecular radius from 1 to 12 nanometers (nm). Curve-stripping methodology, a 3-pore model, and known protein kinetics were then applied to estimate the dimensions of and the net outflow through fenestral, “small,” and “large” apertures in the microvascular endothelium.Results.The 3-pore model correlated highly with the observed data (r = 0.992 in normal and 0.980 in arthritis), yielding the following mean values: for the fenestra, the normal radius (nm) was 1.75 and the effused 3.5, and the normal flow (μl/min) was 1.74 and the arthritic 22.0; for the small pore, the normal radius was 8.6 and the effused 8.5, and the normal flow was 1.5 and the arthritic flow 9.1; for the large pore, the normal radius was 40 and the effused 36, and the normal flow was 0.24 and the arthritic flow 15.5.Conclusion.These findings provide the first functional definition of synovial, endothelial fenestrae; reveal that the “increased vascular permeability” of inflammation is not limited to interendothelial gaps; present evidence suggesting that glycocalyceal damage and aquaporin upregulation may affect permeability in arthritic synovium; and define a straightforward methodology for interpretation of biomarker concentrations in arthritic SF.

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