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OVERTURNING OF CAISSONS BY STORM WAVES

関口秀雄, 大槇正紀

土質工学会論文報告集
1992年 32 巻 3 号 144-155
発行日: 1992/09/15
公開日: 2008/02/29

DOI https://doi.org/10.3208/sandf1972.32.3_144

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This paper concerns the stability against overturning of the caissons on rubble mound subjected to wave loading. A theoretical discussion is first made of the stability of a leaning caisson during wave loading, as a single degree-of-freedom system. The expression for the lower bound of driving moments sufficient to overturn a given caisson is derived. A review is then made of the damages induced to a composite breakwater, which consisted of two adjoining Stretches
B
and C with slightly different sizes of caissons. Attention is called for the observation that most of the caissons in Stretch
B
were overturned, whereas no caissons in Stretch C were brought into overturning. This fact is examined in detail in the light of the theory of overturning, making it possible to estimate the destructive wave heights that are compatible with the observed patterns of damage in Stretches
B
and C of the composite breakwater.
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23pSM-6 Isoscalar and Isotensor π-π Scattering Lengths from K^+_<π3> Decays

T BAKER, C. RANGACHARYULU

日本物理学会講演概要集
1999年 54.2.1 巻 23pSM-6
発行日: 1999/09/13
公開日: 2018/03/04

DOI https://doi.org/10.11316/jpsgaiyo.54.2.1.0_16_3

会議録・要旨集フリー

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The production of nematode-immobilizing secretory cells by Climacodon septentrionalis

Joey
B
. Tanney, Leonard J. Hutchison

Mycoscience
2012年 53 巻 1 号 31-35
発行日: 2012年
公開日: 2023/03/31

DOI https://doi.org/10.1007/s10267-011-0128-1

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The ability of Climacodon septentrionalis to immobilize and kill a mycophagous nematode (Aphelenchoides sp.) in vitro is described for the first time. Two isolates produced droplets (20–45 μm in diameter) that formed at the apices of tall, stalked, and branching secretory cells (700–1,500 μm tall). On
2
% modified malt extract agar, nematodes became enveloped in the droplets, which restricted their ability to move and resulted in complete immobilization and death within several hours of contact. The rate of decomposition of the nematodes varied considerably, with most individuals persisting for weeks whereas others were degraded within several days and appeared to be colonized by dense hyphal growth. This study provides the first documentation of a non-agaricoid fungus producing secretory cells that are able to immobilize nematodes.

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WAVE-INDUCED SEABED INSTABILITY : DIFFERENCE BETWEEN LIQUEFACTION AND SHEAR FAILURE

善功企, /, 大山巧, TAKUMI OHYAMA

地盤工学会論文報告集
1998年 38 巻 2 号 37-47
発行日: 1998/06/15
公開日: 2008/02/29

DOI https://doi.org/10.3208/sandf.38.2_37

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The mechanism of wave-induced instability in a permeable seabed have been studied for more than two decades. The distinction between shear failure and liquefaction, however, has not been clearly defined. This paper presents a fundamental study on the differences in two failure modes for a fully saturated seabed of both finite and infinite thickness. The wave-induced effective stresses and pore pressure, obtained from an analytical solution of Biot's pore-elastic consolidation theory, were employed to examine the failure modes under a two-dimensional plane strain condition. A case study is presented to examine the failure modes with respect to several parameters, such as excess pore pressure, seepage flow, seepage force, failure areas and stress path in the seabed. The conclusions obtained from this study were as follows ; (1) the thickness of a permeable seabed affects the pore pressure and effective stress response to ocean waves and the failure mode of the seabed, (
2
) either a liquefaction or shear failure, or both, occur in the seabed, even in the saturated seabed, (3) the Mohr-Coulomb's failure criterion, when combined with elastic stresses, can not be employed to estimate the liquefaction failure in the seabed, (4) the liquefaction can be evaluated by a criterion in terms of the excess pore pressure, (5) The liquefied zone in the seabed is significantly different from the shear failure zone. The shape beneath the seabed surface for the former is almost identical to the contour where the upward seepage flow is concentrated.
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RESPONSE OF A DENSE SAND DEPOSIT DURING 1993 KUSHIR0-0KI EARTHQUAKE

井合進, 森田年一, 亀岡知弘, 松永康男, 安彦和之

土質工学会論文報告集
1995年 35 巻 1 号 115-131
発行日: 1995/03/15
公開日: 2008/02/29

DOI https://doi.org/10.3208/sandf1972.35.115

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In the 1993 Kushiro-oki Earthquake of Richter magnitude
7
.
8
, simultaneous recording of earthquake motions was successfully made at the ground surface and at a depth of 77 meters in a dense saturated sand deposit. The peak horizontal acceleration was 0.47 g on the ground surface and 0.21 g at a depth of 77 meters. The acceleration record at the ground surface showed a distinctive ground response, which consisted of a cyclic motion having a period of about 1.5 seconds overlain by a spike at each peak of the motion. In order to study the mechanism of this peculiar ground response, effective stress analysis was conducted on the dense saturated sand deposit. The model used for this study was a strain space multiple mechanism model, which takes into account the effect of principal stress axis rotation. The recorded earthquake motion at a depth of 77 meters was used as the input earthquake motion for the analysis. Sampling after in-situ freezing was done in order to evaluate the properties of the sand. The results of the analysis indicated that the observed ground response was due to the effect of dilatancy of sand, which plays a significant role in the response of the dense saturated sand deposits during strong earthquake motions.
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Streptococcus mutans 溶菌酵素産生菌の分布と 1 菌株の産生する酵素の活性

福岡隆俊

九州歯科学会雑誌
1983年 37 巻 1 号 101-113
発行日: 1983/02/25
公開日: 2017/12/22

DOI https://doi.org/10.2504/kds.37.101_1

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Distribution of bacteria which produce enzyme capable of lysing Str. mutans
E
49 strain in human dental plaques was investigated on adults of age 20 to
22
. The activity of the enzyme (MLE) produced by an isolated strain (FDC-63) was also investigated. The results obtained are summarized as follows. 1. MLE producing bacteria were detected in 43 samples (37.1%) out of 116 samples of dental plaques obtained from adults of age 20 to
22
.
2
. Twenty four samples had MLE producing bacteria at the rate of over 5% of total number of bacteria in each sample. 3. The 40 strains isolated were composed of
92
.5% of Gram positive cocci,
2
.5% of Gram negative cocci and 5% of Gram positive rods. 4. Most of the isolates (
84
.6%) showed lytic activity against living cells of
E
49 on GAM agar plates. 5. The MLE produced by FDC-63 had lytic activity against both living and heat killed cells of
E
49 under aerobic or anaerobic condition. 6. The activity of the MLE was rather weak against purified cell walls of
E
49.
7
. Optimal pH in the activity of the MLE was 6.0 and optimal temperature 37℃. The activity of the MLE was lost by heating at 60℃ for 60 min.
8
. FDC-63 was identified as Streptococcus milleri.
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Deexcitation of the 931.1 keV
2₂
+-State of Cd¹⁵²

Yasuyuki Gono, Manabu Fujioka, Tamotsu Toriyama

Journal of the Physical Society of Japan
1970年 29 巻 2 号 255-258
発行日: 1970/08/05
公開日: 2007/06/01

DOI https://doi.org/10.1143/JPSJ.29.255

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The gamma-ray spectrum and the conversion-electron spectrum are measured in the decay of the Tb¹⁵² activity. The L-subshell electron lines of the 586.
7
keV
2₂
+→2₁⁺ transition are separated by the ion-free beta-ray spectrometer. The M1-
E
2
mixing ratio,
δ²
, and the dimensionless ratio X of
E
0-
E
2
mixing of the 586.
7
keV transition are obtained to be
δ²
≤0.16 and 0.034≤X≤0.038, respectively. The
E
2
branching ratio
B
(
E
2
;
2₂
+→0_g⁺):
B
(
E
2
;
2₂
+→2₁⁺):
B
(
E
2
;
2₂
+→0₁⁺) is determined to be 0.023 : 1.0 : 5.6.
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S-026 これからの小児医療に求めること : 母親の立場より(シンポジウム4 小児外科医療を取り巻く環境-小児外科医療の未来像を探る,Better Life for Sick Children, Better Future for Pediatric Surgery,第45回日本小児外科学会学術集会)

和田ちひろ

日本小児外科学会雑誌
2008年 44 巻 3 号 337-
発行日: 2008/05/20
公開日: 2017/01/01

DOI https://doi.org/10.11164/jjsps.44.3_337_2

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右房室弁の形態学的検索

その所属腱索および乳頭筋について

島田博

日本医科大学雑誌
1981年 48 巻 6 号 779-789
発行日: 1981/12/15
公開日: 2010/10/14

DOI https://doi.org/10.1272/jnms1923.48.779

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Although there have been numerous articles concerning the anatomy of the atrioventricular valve in man, only a few publications have recorded the relationship between the chordae tendineae and the papillary muscles. The purpose of this paper is to study the relationship among the shape and size of the atrioventricular valve, the chordae tendineae and the papillary muscles. 50 subjects, as listed in Table 1, were analyzed by the Taniya-Hashimoto Method.
The results obtained were as follows:
1) The right atrioventricular valve was classified into two types: 33 cases (66%) of three irregularly shaped cusps, i.
e
. type I, and 17 cases (34%) of four or five cusps, i.
e
. type II.
2
) The average circumference of the right atrioventricular orifice (ostium atrioventriculare dextrum) was 11.96cm (9.63.15.06cm) in type I and 12.19cm (9.52.15.
22
cm) in type H. There existed no significant difference in the circumference of the atrioventricular orifice between type I and II.
3) The average length of the cusp-fundus (the length of the fixed margin of the cusp) was as follows:
type I: anterior cusp…………4.13cm (
2
.03-6.96cm)
posterior cusp…………3.62cm (1.21-5.44cm)
septalcusp……………4.21cm (3.11-6.08cm)
type II: anterior cusp…………4.10cm (
2
.68-5.42cm)
posterior cusp…………3.67cm (0.
94
-5.70cm)
septal cusp……………4.43cm (
2
.96-6.53cm)
4) The average width of the cusp (the maximum distance between the apex and the fundus of the cusp) was as follows:
type I: anterior cusp…………1.86cm (1.26-
2
.29cm)
posterior cusp…………1.62cm (0.62-
2
.
94
cm)
septal cusp……………1.76cm (1.15-
2
.72 cm)
type II: anterior cusp…………1.
92
cm (1.40-
2
.34cm)
posterior cusp…………1.72cm (0.
94
-
2
.42cm)
septal cusp……………1.
84
cm (1.14-
2
.53cm)
The length or width of the cusp in type I was similar to that in type II.
5) The papillary muscles consisted of five groups, which were named the anterior, postlateral, postmedial, postseptal and septal muscles. The average number of the papillary muscles per right ventricle was 5.
7
(
2
.0.9.0). The chordae tendineae from the anterior papillarymuscles were attached to the anterior and posterior cusps and those from the postlateral and postmedial muscles were attached to the posterior and septal cusps. The chordae tendineae from the postseptal muscles were linked only to the septal cusp and those from the septal muscles were connected to the septal and anterior cusps.
6) The average number of the stems of the chordae tendineae from the papillary muscles were as follows:
From the anterior papillary muscles………
7
.
2
(
2
.0-14.0)
the postlateral papillary muscles……3.5 (1.0-
8
.0)
the postmedial papillary muscles……4.0 (1.0-
8
.0) the postseptal papillary muscles……4.5 (1.0-13.0) the septal papillary muscles………5.
7
(
2
.0-12.0)
The average n umber of the stems of the chordae tendineae per right ventricle was 24.4 (16.0-35.0).
7
) The tip of the chordae tendineae are attached to the fixed margin of the valve cusp, i.
e
. type A, to the ventricular surface, i.
e
. type
B
and to the free margin, i.
e
. type C. The average number of them were 23.4 (14.0-32.0) in type A, 19.
2
(4.0-37.0) in type
B
and 68.1 (31.0-105.0) in type C. The average number of the apexes of the chordae tendineae per right ventricle was 110.
7
(53.0-166.0).
8
) The average number of the chordae tendineae for the anterior cusp was 34.9 (12.0-64.0), for the posterior cusp 30.5 (5.0-65.0) and for the septal cusp 45.3 (23.0-68.0).
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PREDICTION METHOD ON DEFORMATION BEHAVIOR OF CAISSON-TYPE SEAWALLS COVERED WITH ARMORED EMBANKMENT ON MAN-MADE ISLANDS DURING EARTHQUAKES

金谷守, 河井正, 栃木均

地盤工学会論文報告集
2001年 41 巻 6 号 79-96
発行日: 2001/12/15
公開日: 2008/02/29

DOI https://doi.org/10.3208/sandf.41.6_79

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In this paper, centrifuge shaking table tests were conducted in order to understand the performance of seawalls during a seismic event. The model tests showed that the displacement of the caisson was much affected by the seaward shear deformation of the sand seabed beneath it during shaking. It was also confirmed that an armored embankment played an important role in the displacement of the caisson during shaking. Based on these test results, a two-dimensional DEM-FEM coupled analysis method was newly developed to numerically predict the deformation of seawalls covered with armored embankments during earthquakes. The movements of the armor units were calculated by DE analysis and deformations of the caisson, rubble mound, sand seabed and backfill were calculated by FE analysis considering the non-linearity of the soil materials based on the effective stress. Dynamic interaction was taken into account by delivering the nodal displacements of the finite elements or the nodal forces converted from the contact forces through the imaginary distinct elements defined at the boundaries between the DE and FE domain. The applicability of this method to the prediction of the deformation of seawalls was verified through numerical simulations of the centrifuge model test.
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INVERSE ANALYSIS OF DYNAMIC SOIL PROPERTIES BASED ON SEISMOMETER ARRAY RECORDS USING THE EXTENDED BAYESIAN METHOD

本城勇介, 岩本悟志, 杉本三千雄, 鬼丸貞友, 吉澤睦博

地盤工学会論文報告集
1998年 38 巻 1 号 131-143
発行日: 1998/03/15
公開日: 2008/02/29

DOI https://doi.org/10.3208/sandf.38.131

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Seismic records obtained from a seismometer array located in downtown Tokyo Japan for about ten years were inversely analyzed to estimate the dynamic soil parameters. Due to the illposed nature of the problem, the simple and often used "least square method" does not properly estimate the parameters. The Extended Bayesian Method combined with the Akaike Bayesian Information Criterion was introduced to overcome this difficulty. The results obtained were compared with dynamic triaxial test results obtained at the time of the seismometer installation. The shear moduli agree quite well with the estimated results, however the damping ratios estimated are slightly higher than the ones obtained in the laboratory.
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EFFECTS OF SOIL PLUG ON BEHAVIOUR OF DRIVEN PIPE PILES

松本樹典, 武井正孝

土質工学会論文報告集
1991年 31 巻 2 号 14-34
発行日: 1991/06/15
公開日: 2008/02/29

DOI https://doi.org/10.3208/sandf1972.31.2_14

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Stress wave theory is applied to open-ended pipe piles to clarify the effects of soil plug on the behaviour of piles during driving and static loading. Measured field data and various numerical models are reviewed ; methods are presented to calculate wave propagation in both the pile and the soil plug ; modelling is presented which takes into account the interaction between the soil plug and the pile ; also presented is simplified method to estimate the loadsettlement relation of the pipe pile in static loading. By correlating observed and calculated values in two analytical cases, the authors demonstrate that incorporation of the soil plug (modelled as a series of masses and springs) is required to correctly predict pile behaviour during driving and static loading.
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Cell-mediated Cytotoxicity of Tumor Infiltrating Lymphocytes on Rat Bladder Cancer

長谷川親太郎

The Keio Journal of Medicine
1992年 41 巻 3 号 146-153
発行日: 1992年
公開日: 2009/03/27

DOI https://doi.org/10.2302/kjm.41.146

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Tumor-infiltrating lymphocytes (TIL) were tested for cytotoxicity against autologous tumor cells in a study utilizing a chemically induced cancer ofthe bladder (transitional cell carcinoma),
BC
-47, in inbred ACI/N rats. From tumors grown after subcutaneous implantation of
BC
-47 in the rats TIL were separated by density gradient centrifugation and incubated in plastic dishes for separation of non-adherent from adherent cells. The non-adherent cells were further fractionated into T and
B
cells by the panning method using anti-rat F(ab')_{2
antibody. The cell fractions were each added to BC
-47 in culture to be assessed for antitumor effect by the crystal violet dye exclusion method and 3H-thymidine incorporation inhibition assay. Peripheral blood mononuclear cells (PBMC) were also tested as described above. TIL expressed significantly higher cytotoxicity against BC
-47 with the mean % cytotoxicity of 56.6±5.6% and 87.5±7
.1% at E
/T ratios of 10:1 and 20:1, respectively, as compared to PBMC(9.9±5.0% at E
/T 10:1) (P<0.001). The adherent cells, B
and T cell fractions showed respective % cytotoxicity of 92
.4±2
.8
%, 57.9±10.6% and 9.9±7
.8
% at an E
/T ratio of 10:1. TIL pretreated with IFN or rIL-2
for 24or 48 hours did not exhibit any noticeably enhanced antitumor activity at an E
/T ratio of 5:1. Prevention of direct contact of BC
-47 cells and TIL by an interposed Millipore membrane (0.45μm) resulted in an unequivocal reduction of antitumor effect. This finding clearly indicates that the direct contact with BC-47cells and TIL is necessary for TIL to manifest their cytotoxicity against the autologous tumor cells, suggesting that TIL exhibit autologous tumor killing activity through cell-mediated cytotoxicity.
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Stimulative Effects of (
22E
,24R)-Ergosta-
7
,
22
-diene-3β,5α,6β-triol from Fruiting Bodies of Tricholoma auratum, on a Mouse Osteoblastic Cell Line, MC3T3-
E
1

Keishi Hata, Fuyuki Sugawara, Naganori Ohisa, Saori Takahashi, Kazuyuki Hori

Biological and Pharmaceutical Bulletin
2002年 25 巻 8 号 1040-1044
発行日: 2002年
公開日: 2002/08/01

DOI https://doi.org/10.1248/bpb.25.1040

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We screened the differentiation-inducing activities of 39 mushroom extracts from Akita prefecture, Japan, on the mouse osteoblastic cell line, MC3T3-
E
1. Sixteen phosphate buffered saline (PBS),
8
boiled PBS, 14 ethanol and 12 methanol extracts induced alkaline phosphatase (ALP) activities, an indicator of MC3T3-
E
1 cell differentiation. The enzyme activities were markedly induced by extracts of Tricholoma auratum, and we isolated the active compound from methanol extracts of this mushroom. Physical data for the isolated active compound were identical to those for (
22E
,24R)-ergosta-
7
,
22
-diene-3β,5α,6β-triol (1). 1 induced ALP activities of MC3T3-
E
1 cells and promoted cell proliferation. To investigate the relationships between the chemical structure and differentiation-inducing activity of the compound, ALP-inducing activities of MC3T3-
E
1 cells by 1, ergosterol (
2
), ergocalciferol (3), cholesta-3β,5α,6β-triol (4),
7
-dehydrocholesterol (5) and cholecalciferol (6) were tested. The enzyme activities of MC3T3-
E
1 cells were increased 3.0-fold by 10 μM 1 and
2
.4-fold by 10 μM 4. However,
2
, 3, 5 and 6 did not induce MC3T3-
E
1 cell ALP activity at 0.1—10 μM. These results suggested that the OH groups at C-5 and/or C-6 of 1 and 4 played an important role in their differentiation-inducing activities on MC3T3-
E
1 cells. Furthermore, 1 suppressed induction of MC3T3-
E
1 cell apoptosis by serum starvation.
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The Properties of 2112 keV Level in ¹¹⁶Sn

Yukichi Yamaguchi, Jian-zhi Runan(Gen), Teruaki Nagahara

Journal of the Physical Society of Japan
1975年 38 巻 4 号 911-916
発行日: 1975/04/15
公開日: 2007/06/01

DOI https://doi.org/10.1143/JPSJ.38.911

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The gamma-ray spectrum and the conversion-electron spectrum are measured in the decay of the ^116mIn activity. Directional correlations are also measured for 818–1293 and 1097–1293 keV cascades. The M1-
E
2
mixing ratio δ, and the
E
0-
E
2
mixing ratio μ_k are obtained for 818.
7
keV
2₂
+→2₁⁺ transition to be δ=1.52_{−0.22
+0.26, and μ_k≤6.1×10⁻⁴ respectively. The E
2
branching ratio B
(E
2
; 2₂
+→0_g⁺): B
(E
2
; 2₂
+→2₁⁺): B
(E
2
; 2₂
+→0₁⁺) is determined to be 0.0158:1.0:5.86.
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V_s DETERMlNATION FROM STEADY STATE RAYLEIGH WAVE METHOD

時松孝次, 桑山晋一, 田村修次, 宮寺泰生

土質工学会論文報告集
1991年 31 巻 2 号 153-163
発行日: 1991/06/15
公開日: 2008/02/29

DOI https://doi.org/10.3208/sandf1972.31.2_153

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An improved version of steady state Rayleigh wave method is presented for the determination of shear wave velocity (V_s) Profiles of a horizontally stratified soil deposit. A dispersion curve and particle orbits of Rayleigh waves can readily be determined in the field through measurements of ground motions induced by an exciter using sensors placed on the ground surface. To determine V_s-profile from the dispersion curve, an inverse analysis which can take into account higher modes of Rayleigh waves is presented and used. To increase the effectiveness of the proposed method, desirable distances among the exciter and sensors are indicated, and the measured particle orbits are used to validate the inverted V_s-profile. Comparative field tests are made at two sites using the proposed method and the conventional down hole method. The V_s-profiles from the two methods are in good agreement with each other, indicating the effectiveness of the proposed method.
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SETTLEMENTS IN FINE-GRAINED SOILS UNDER CYCLIC LOADING

安原一哉, 村上哲, 豊田紀孝 /, ADRIAN F.L. HYDE

地盤工学会論文報告集
2001年 41 巻 6 号 25-36
発行日: 2001/12/15
公開日: 2008/02/29

DOI https://doi.org/10.3208/sandf.41.6_25

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Based on the methods previously presented by the authors (Yasuhara et al., 1992, 1994, 1996) for predicting the degradation in strength and stiffness of soft clays in the course of cyclic loading, a methodology has been developed to estimate the cyclic loading-induced settlements. The method also includes not only immediate settlements but also post-cyclic long-term settlements due to dissipation of cyclically induced excess pore pressures in soft soils. The simplified formulae included in the proposed methodology are given as functions of the amplitude of cyclic-induced excess pore pressure normalized by the confining pressure, u/p'_c, plasticity index I_p and factor of safety against bearing capacity failure, F_s. The calculations of cyclic-induced settlements were conducted for soft soil deposits with different index and geotechnical properties. The results calculated using the proposed methodology are presented in the form of a design chart to give the settlement versus normalized excess pore pressure ratio relations including the effects of the plasticity index and safety factor for bearing capacity. An example of the calculated results using the proposed procedure for the earthquake-induced settlements of embankments founded on soft clay, is presented to demonstrate the practicality of the method for design at fields.
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EFFECTIVENESS OF TOP-SHAPED CONCRETE BLOCKS IN PREVENTING SETTLEMENT OF FOUNDATIONS IN LIQUEFIED GROUND

安田進, 伯野元彦, 永瀬英生, 小林正二郎, 吉田剛

土質工学会論文報告集
1994年 34 巻 1 号 65-76
発行日: 1994/03/15
公開日: 2008/02/29

DOI https://doi.org/10.3208/sandf1972.34.65

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Shaking table tests were performed to clarify the settlement in liquefied loose sand of a new foundation incorporating top-shaped concrete blocks. In the tests, blocks of half scale were installed as they are in practice, by using a crusher-run, a lattice of iron rods and iron bars. Shaking table tests were also conducted on foundations with two differently shaped concrete blocks to investigate the effectiveness of the three foundations in reducing settlement. One was a T-shaped concrete block, or a disk-shaped concrete plate with a leg. The other was a conical concrete block without a leg. The results of shaking table tests showed that the foundation with the top-shaped concrete blocks was most effective in reducing the settlement among the three types of foundation. FEM elastic analyses were performed to compute the stress distributions in the models and in-situ ground when the top-shaped concrete blocks were applied and to confirm whether liquefaction resistance of the sand layer below the foundation is large. Moreover, the factor of safety against liquefaction, F_L was evaluated in in-situ model ground, in order to compare with sensitivities against liquefaction in the ground without countermeasures and with top-shaped concrete blocks. For the liquefaction analyses, shear stress in the ground during an earthquake was estimated by dynamic analyses using the SHAKE computer program.
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THE MODIFIED "STIFFENED" DRNEVICH RESONANT COLUMN APPARATUS

ANESTIS S. AVRAMIDIS, SURENDRA K. SAXENA

土質工学会論文報告集
1990年 30 巻 3 号 53-68
発行日: 1990/09/15
公開日: 2008/02/29

DOI https://doi.org/10.3208/sandf1972.30.3_53

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The original Drnevich Resonant Column apparatus has been designed for testing cylindrical soil specimen with maximum longitudinal and torsional stiffnesses corresponding to approximate resonant frequencies 285 Hz and 318 Hz respectively. This apparatus has been modified successfully and its stiffness has been increased to over threefold in the longitudinal vibratory mode and at least twofold in the torsional vibratory mode. Monterey No. O sand samples prepared at approximate relative densities 43% and 60% were tested with the original and the modified apparatus in the range of effective confining pressures from 49 kPa to 588 kPa. Measurement of dynamic moduli values measured with the original apparatus were up to 23% higher, and damping values up to five times higher than those measured by the modified apparatus.
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PERFORMANCE-BASED ANALYSIS OF EARTH DAMS: PROCEDURES AND APPLICATION TO A SAMPLE CASE

STEFANIA SICA, LUCA PAGANO

SOILS AND FOUNDATIONS
2009年 49 巻 6 号 921-939
発行日: 2009年
公開日: 2011/01/27

DOI https://doi.org/10.3208/sandf.49.921

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The paper illustrates theoretical and experimental procedures adopted to characterize the seismic response of earth dams by performance-based criteria. The study refers to a real case, the Camastra Dam, a zoned earth dam with vertical clay core, placed in a highly seismic zone of Southern Italy. At first, the analysis objectives have been identified along with the physical quantities needed to achieve them for characterizing dam seismic performance. A theoretical approach, consistent with the identified analysis objectives, has been later selected. The adopted approach is based on continuum mechanics and accounts for coupling between soil skeleton and pore water phase. It is also able to describe the main features of soil response under cyclic loading conditions since it implements an advanced constitutive law for the soil skeleton. Big effort has been paid to the mechanical characterization of the dam materials. In addition to data coming from the interpretation of the laboratory tests performed at the time of dam construction, in situ tests (SASW, Down Hole, DMT) have been recently carried out on the embankment and foundation soils and interpreted consistently with the requirements of the selected theoretical model. Preliminarily, the static stages of the dam lifetime have been numerically simulated to reproduce the behaviour observed in terms of cross-arm settlements and pore water pressures, in order to obtain or verify some soil parameters and initialize the state variables for the simulation of the seismic stages. A seismological study of the dam site provided the expected seismic scenarios in terms of time histories of acceleration, needed as input for the dynamic analyses. The seismic response of the Camastra Dam was finally investigated and discussed in the light of performance-based criteria.

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