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 and C with slightly different sizes of caissons. Attention is called for the observation that most of the caissons in Stretch 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 and C of the composite breakwater.

抄録全体を表示

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, () either a liquefaction or shear failure, or both, occur in the seabed, even in the saturated seabed, () 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.

抄録全体を表示

All the birds examined were also associated with bone dysplasia (art alczaormal develop-ment of bone tissue) in the diaphyseal cortex of the leg bones, especially of bones affectedwith dyschondroplasia. This result is very significant in order to clarifyz tlais disease entity.1970:J14, k -1 } ) , M77 ) i? ht /, ( K ) (C # L"C, MB @ () t, If!TB& U "C, Jff Dyschondroplasia (1*t%fi!dW) ().g:#[!:.fLlt! K?o, [1: ()M;tC, rff.?U/:cD, =1lC#li6*H(DX15RI!!D& t, r, ccl)Efffflr.#.??t"ut:.?T<.1.?l??/?t:>"A??1!? > >?TMOll?, lI]%G (-srRM) -ts;5;.*BI) *M[t fL 54 5 t:.;*.{1*I[l?(), t@Yllll*fJ?H@() %?Jfipj@ (Dyschondroplasia) p, }, (, 1lTi{-X, WIKIM itt{= t D"tl%tff{tO 1111IH(-UP!z U-ii) >ES- -)%Wi*fd?1J*[lEj: >11"i6ifI".*"H*Tl*&Z") #)/?-"k l - vich ) J&it(VhiO"= >If-ffi"!1lYl*I4")Ji/l![40111!>D*!)<Y14M)?A"!>CL(Il], k.ClT"ltTt*flB1? & $4U [-" C U" L % w, Zl1*.IlBl tI1J, FA(y L-x") LVfAK t: >llltPJ4IiI " } ) t- ! Al j: >kP11liR6, &ffl(C5NWi Z lk(C#L" Ct ?!4M"C- fL#, -()%.IWMd1.XI1*I1EPW(tit ff1lR)

抄録全体を表示

In the 1993 Kushiro-oki Earthquake of Richter magnitude ., 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.

抄録全体を表示

Two new partially saturated tricyclic ring systems, 6, 6a, , , , 10, 10a, 11-octahydro-11-oxodibenz [, ] oxepins (a and ), and -thiepins (4a and 4) were synthesized. Compounds 4a and 4 were desulfurized to give a pair of isomeric -methylbenzoylcyclohexanes (10a and 10). Deuterated 4a and 4 (11a and 11) were prepared starting from butadiene-d₆ (12). The stereochemical features of a (trans), (cis), 4a (trans) and 4 (cis) are compared with those of 10a, 10, 11a and 11 on the basis of proton nuclear magnetic resonance data.

抄録全体を表示

The uplift behavior of sewage manholes due to liquefaction in a trench is investigated through a series of dynamic centrifuge model tests. The objectives of a series of tests are to study the mechanism of the uplift and to obtain relationships among uplift displacement and factors affecting the uplift. The factors considered in the experiments are the ground water levels, the magnitude of input accelerations, the duration time of shaking, the relative densities of trench backfill and the native ground, the material of native ground, the volume of a trench, the apparent unit weight of a manhole, and the contact conditions at the bottom of a manhole. Test results show that the primary cause of uplift is the reduction of the effective confining stress near the bottom of a manhole due to strong shaking. The magnitude of uplift is found to be strongly correlated with the ground water depth, the intensity of shaking, the shear deformation of the trench, and the contact conditions at the bottom of the manhole. These findings are believed to be useful for engineering practice in the mitigation of the manhole uplift.

抄録全体を表示

Six new cembranoids sarcophytol P (), R (4), S (5), K (), (11), and T (13) were isolated from the soft coral Sarcophyton glaucum. Sarcophytol P () was shown to be the 20-hydroxy derivative of the major component sarcophytol A (1), and afforded the cyclization product 6 in CHCl_ at room temperature, in a same way as in 1. Sarcophytols R (4) and S (5) were correlated to 1, by conversion of its R,R and S,S epoxide derivatives. Sarcophytol K() was a 13, 14-dihydroxycembranoid having a 1,Z-diene moiety. The absolute configuration of and its 1Z,- and 1Z,Z-isomers sarcophytol () and J (10) were determined by circular dichroism study of their bis-p-dimethylaminobenzoate derivatives. Sarcophytols (11) and T (13) were 1- and 1,Z-isomers of 1. Compound 11 showed characteristic broadening of the ^1H-NMR chemical shifts, due to the restricted conformational interconversion. Using the three cembranoids sarcophytols (11, 1,), N (15, 1Z,Z) and T (13,1,Z), spontaneous autoxidation-cyclization, in CHCl_,was examined, in order to compare the stereochemical course of the reaction with that of 1 (1Z,), which affords trans-fused bicyclo[..0]tetradecene systems. The 1,Z-isomer 13 gave the same cyclization product 18, as in the reaction of 1, even though it is isomeric at C-1,. The 1Z,Z isomer 15 gave 19, in consequence of the reversed geometry at C- of 15. The 1,-isomer (11) gave the bicyclic product , having an antipodal fusion as compared with 19. This was confirmed by PCC oxidation of 19 and , giving enantiomeric ketones 23 and 24 respectively. The 1(14)-epoxide 26 was shown to be the immediate precursor of , and acounted for the inversion of the geometry at C-1 of the cyclization product. Compound 26 is isomeric with the epoxide 17 derived from 1. The epoxide 17 is the postulated precursor in the conversion of 13 to 18. It is noteworthy that the mode of antipodal fusion of the cyclopentane rings, in 18 and , was controlled by the chirality of the epoxy rings. The C-14 hydroxyl group participates in the transannular cyclization, but was found not to be the requisite functional group for the reaction. Similar treatment of cembrene C (30), the parent hydrocarbon of 1, also reacted in CHCl_ giving the bicyclic product 32.

抄録全体を表示

This study aimed to determine the prevalence of fecal carriage of extended spectrum β-lactamase (ESBL) and/or plasmidic AmpC β-lactamase (pAmpC) producing Escherichia coli among dogs (n=428) in Turkey. Polymerase chain reaction (PCR) and sequencing were used to characterize genes encoding β-lactamase and plasmid mediated quinolone resistance (PMQR). Antimicrobial susceptibility testing and PCRs for virulence genes and phylogenetic groups were also performed. Cefotaxime resistant

. coli isolates were detected in 95 (.%) of the swab samples. Sequencing analysis results showed occurrence of various β-lactamase genes: bla_CTX-M-15 (62), blaTEM-

1b

(42), blaCMY-

2

(

22

), blaCTX-M-

3

(16), bla_CTX-M-1 (15), bla_OXA-1 (

9

) and bla_SHV-12 (

3

) alone or in combination. The most frequently encountered phylogenetic group was group A₁ (35.

8

%), followed by group

D₂

(

22

.1%),

B

1 (15.

8

%), D₁ (

9

.5%), A₀ (

7

.4%),

B2₂

(5.

3

%) and

B2₃

(4.

2

%), respectively. PMQR genes, aac(6’)-Ib-cr, qnrS1 and qnrB10 were detected in 25.

3

, 10.5 and 1.1% of the isolates, respectively. While all isolates were susceptible to imipenem and amikacin, resistance rates to non-β-lactam antibiotics ranged from 20.0% for tobramycin to 56.

8

% for tetracycline. The virulence genes were only detected in 34 (36.

2

%) of the isolates and this isolates carried single or various combination of virulence genes of iucD, papC, papE,

f17a

-A and eaeA. Four isolates were identified as human virulent pandemic CTX-M-15 producing

E

. coli clone O25

b

:ST131/

B

2

. To the best of our knowledge, this is the first study to show fecal carriage of ESBL/pAmpC type β-lactamase producing

E

. coli isolates among dogs in Turkey.

抄録全体を表示

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.

抄録全体を表示

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.

抄録全体を表示

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.

抄録全体を表示

11-Amino-6, 6a, , , , 10, 10a, 11-octahydrodibebenzo[, ]thiepines (6a-d) and -oxepines (a-d) were synthesized by the Leuckart reaction of 6, 6a, , , , 10, 10a, 11-octahydro-11-oxodibenzo[, ]thiepines (1a, )and -oxepines (a, ) followed by hydrolysis of the reaction products 4a-d and 5a-d, respectively. The four diastereomers, cis(6a-H, 10a-H)-cis(10a-H, 11-H) 6a and a, cis(6a-H, 10a-H)-trans(10a-H, 11-H) 6 and , trans(6a-H, 10a-H)-trans(10a-H, 11a-H)6c and c, and trans(6a-H, 10a-H)-cis(10a-H, 11-H) 6d and d, were isolated and their configurations and conformations were elucidated by chemical methods together with ¹H-nuclear magnetic resonance spectroscopic and X-ray crystallographic analyses.

抄録全体を表示

Reactions of nor-diterpenoid dilactones isolated from Podocarpus plants have been investigated. The : ,: 11-dienolide type [C] dilactones, the least available but biologically the most active members, are mainly derived from naturally abundant dilactone components of α-pyrone type [A] and : -epoxy-: 11-enolide type [] for total-synthetic and biological purposes. From nagilactone (5), for example, a combined sequence of hydrogenolysis of : -epoxide group and dehydration gives nagilactone (), β-hydroxynagilactone () and : -dehydronagilactone (19), which have been found from natural sources. From nagilactone A (1), photo-hydration and concomitant double bond migration of its acetate results in a lactol (), which is reduced to 1β-hydroxynagilactone (), another natural type [C] dilactone. Derivation of the type [A] or [] from others is not successful. Some attempts for conversion of the ring A functional groups have also been studied.

抄録全体を表示

  The distribution of sarcophytol-A in the Sarcophyton genus was investigated in seven samples belonging to S. glaucum ( samples), S. infundibulifurme ( samples), S. crassocaule (1 sample) and S. trocheliophorum (1 sample) that were collected on Ishigaki Island in Okinawa Prefecture. Sarcophytol-A was present in one sample each of S. glaucum and S. infundibulifurme. This study indicates that the composition of cembranoids in the Sarcophyton genus is not related with the respective species, but with the individual samples collected.

抄録全体を表示

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.

抄録全体を表示

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.

抄録全体を表示

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.

抄録全体を表示

Four new sterols, 5α, 6α-epoxy-(, 24R)-ergosta-(14), -diene-, -diol (1), (, 24R)-ergosta-, -diene-, 5α, 6β, -tetrol (), (, 24R)-ergosta-, (11), -triene-, 5α, 6β-triol () and , 5α, 6β-trihydroxy-(, 24R)-ergost--en--one (4), have been isolated from the fruit bodies of Grifola frondosa (FR.) S. . GRAY (Polyporaceae)together with fourteen known ones (5-18), of which two (5 and 6) are reported for the first time from a natural source. The structures of these compounds were elucidated on the basis of spectral data.

抄録全体を表示