Search

Orthoses and insoles are among the primary treatments and prevention methods of refractory plantar ulcers in patients with Hansen&rsquo, s disease. While dynamic plantar pressure and tactile sensory disturbance are the critical pathological factors, few studies have investigated whether a relationship exists between these two factors. In this study, dynamic pressure measured using F-scan system and tactile sensory threshold evaluated with monofilament testing were determined for 12 areas of 20 feet in patients with chronic Hansen&rsquo, s disease. The correlation between these two factors was calculated for each foot, for each clinical category of the foot (0&ndash, IV) and across all feet. A significant correlation was found between dynamic pressure and tactile sensation in Category II feet (n = 8, p = 0.016, r2 = 0.246, Spearman&rsquo, s rank test). In contrast, no significant correlation was detected for the entire foot or within the subgroups for the remainder of the clinical categories. However, the clinical manifestation of lesion areas showed high variability: (1) pressure concentrated, sensation lost, (2) margin of pressure concentration, sensation lost, (3) pressure concentrated, sensation severely disturbed but not lost, and (4) tip of the toe. These results may indicate that, even though there was a weak relationship between dynamic pressure and tactile sensation, it is important to assess both, in addition to the basics of orthotic treatment in patients with Hansen&rsquo, s disease presenting with refractory plantar ulceration.

On March 11, 2011, the largest earthquake ever recorded in Japan struck off the coast of the Tohoku region of the country, and was subsequently named the 2011 off the Pacific coast of Tohoku Earthquake by the Japan Metrological Agency. The M w 9.0 earthquake generated strong motions that affected the island of Honshu from Tokyo Bay to the northern extent of the island, and induced a series of tsunamis that devastated coastal communities throughout the region. Significant aftershocks ( M w >7) were experienced that further contributed to damage in the coastal Tohoku region during emergency response and recovery efforts. This paper summarizes the findings of the Port and Airport Research Institute (PARI) research team as it investigated coastal structures along approximately 600 km of coastline as well as the team׳s follow-up experiments and analyses. Two characteristics of the ground motion observed were the long duration and the high-frequency component. For this reason, the degree of damage caused to coastal facilities by the ground motion was relatively small. The wide-ranging investigation by the PARI team facilitated the interpretation of damage patterns across the entire region affected by the earthquake, with a primary goal of distinguishing damage to coastal structures resulting from strong ground shaking and secondary effects (such as liquefaction, ground failures, and settlement) from that caused by the subsequent and significant tsunami inundation.

地表面勾配が0.5～3%前後の工学的に水平な地盤において，数mオーダーの水平変位を伴う流動現象が報告されている．本論文は，滑走路地盤の部分改良に関する流動対策として，改良層の両端部を非液状化層に着底させる門型着底構造を提案するものである．本文では，流動現象を改良層の滑動問題として帰着させた着底幅に関する基本検討を示し，1G場の模型実験から門型着底構造の流動対策効果を考察する．さらに，模型実験を概ね再現しうる解析手法を用いて，モデル滑走路地盤によるパラメトリックスタディを実施した．その結果，本研究で対象とする滑走路地盤では，地表面勾配の影響が大きいものの，部分改良75%で未改良ケースの水平変位を8割程度低減することや，提案した門型着底構造で水平変位の発生をほぼ抑止できる可能性が示唆された．

基礎地盤が置換砂となっている防波堤は，地震時に置換砂の液状化により大きく沈下すると予想されている．この沈下量が大きければ，地震後に続く津波や高潮から沿岸地域を防護することはできない．したがって，地震による液状化の発生を予測し，防波堤の沈下量を精度良く把握することが性能設計では重要となる．本論文では液状化が発生した基礎地盤の変形とそれに伴う防波堤の沈下量を把握するため，大型模型振動実験を実施した．その結果，防波堤は基礎地盤の過剰間隙水圧の上昇とともに大きく沈下し，基礎地盤はケーソン下より外側へ押し出されるように変形した．また，実験の再現性を確認するため二次元有効応力解析を実施し，実験結果と良く整合した基礎地盤や捨石マウンドの変形を得た．

The role of an airport during and after a great earthquake is important because of its helpful function for emergency medical services and special activities of the transport of relief supplies to the disaster areas. In this study, the authors conducted a full-scale field experiment on liquefaction phenomena induced artificially by controlled-blast technique in the experimental site at the Ishikari Bay New Port in Hokkaido Island, in order to investigate the influence of a great earthquake on the airport's function in Japan. This experiment especially focused on the assessment of the performance of runway pavement and the effect of densification method as countermeasure for liquefaction with a cost-reduction design. This study concludes that densification method examined with cost-reduction design in this experiment keeps its effectiveness based on results of measurements of liquefaction behavior of liquefied layer and runway pavement, ground investigations after liquefaction and liquefaction-induced residual deformation analysis.

巨大地震時あるいは地震後において，空港の果たす役割は，被災地への緊急物資輸送や救急医療の観点から非常に重要である．しかし，実際に大規模地震が襲来した際に，どのような被害や影響を受けるのかといった被災予測が困難であるのが現状であり，事前に講じるべき対策について早期の確立が求められている．本研究では，臨海部の埋立て地を始めとする軟弱地盤上に施工された滑走路の合理的な液状化対策を検討するため，実大滑走路試験体を施工し，制御発破により地盤の液状化を実際に発生させる現場実験を試みた．本実験から得られた結果より，液状化地盤上の滑走路の挙動観測，液状化対策効果や未対策部分に関する被害の比較・分析を実施し，液状化対策の仕様について検討したので報告する．

溶液型薬液注入工法は，地盤中の間隙水を浸透注入した薬液に置換し固化することで，液状化の要因となる過剰間隙水圧の発生を抑制する液状化対策工法である．薬液により固化された砂については，粘着力が増加し液状化抵抗が増加することが知られているが，地震後，改良体周辺の液状化地盤に生じた過剰間隙水圧消散に伴う改良体に与える影響についての議論が少ないのが現状であると考えられる．そこで，本報では，液状化対策効果確認を目的とした現場液状化実験を実施した際に，ブロックサンプリングによる改良体の不攪乱試料を採取した．この改良砂と改良前の砂質土を対象に，三軸試験により非排水せん断特性，繰返し載荷後の体積変化特性を調べ，現場液状化実験における過剰間隙水圧消散に伴う沈下量についての簡易算定を行ったので報告する．

多様な施設が設置されている空港では，地盤が液状化した場合，様々な施設が機能しなくなることが懸念される．特に，地震後において平坦かつ所定の支持力が要求される滑走路では，液状化による地盤変状に伴う不等沈下等の被害が予測されるが，被害が局所的であっても全面的に供用ができない可能性があると考えられる．滑走路における局所的な変状や不同沈下量を予測するためには，事前に地盤の状況を詳細に把握しておく必要があるが，敷地内において平面的に点の調査であるボーリング調査では限界がある．そこで，本論文では，滑走路地盤の液状化調査を目的に，既存ボーリング調査結果の補間手法として幾つかの物理探査を実際の滑走路地盤で実施し，その結果を用いた簡易検討を実施した．

空港は地震災害時には緊急物資輸送の拠点等としての役割を果たし，非常に重要な社会基盤施設の一つである．大規模地震の襲来時，供用の可否判定をするにあたり，被災程度に応じ対応が異なってくることから，実際にどの様な被害が起こり得るかの把握が必要となる．本研究では，臨海部の軟弱地盤上に施工された滑走路を想定し，実大滑走路試験体を現場に施工し，制御発破により地盤の液状化を発生させ，実際の被災程度の把握を試みた．水準測量より液状化に伴うアスファルト舗装の変状を把握するとともに，地表面では確認できない液状化によるアスファルト舗装下の空洞化や地盤の緩みを調べるため地中レ-ダ-探査を実施し，被害傾向についてまとめた．

関西国際空港で広く用いられている緩傾斜石積護岸について，地震時の残留変位を検討した．関西空港で用いられているような規模の緩傾斜石積護岸の地震時挙動については，既往の検討事例が少なく，また被災した事例もない．そのため，既往の解析プログラムを用いて地震時残留変位を求めるには，パラメータの設定方法など様々な問題があり，解析が困難である．そこで，本研究では，1G場での振動模型実験，実際に現地で使用した材料の液状化判定，現地における常時微動観測等を組み合わせ，総合的な検討を実施した．その結果，検討対象とした条件下においては，緩傾斜石積護岸に大規模な地震時残留変位は生じないと結論づけた．

A series of large-scale underwater shaking table tests was performed on a gravity type model caisson protected by a cushioning technique using tire chips (scrap tire derived recycled product). The function of the tire chips cushion is to reduce the load and restricting the permanent displacement of such waterfront retaining structures during earthquakes by exploiting the compressibility, the ductility and the energy absorbing capacity of tire chips. The seismic performance of such earthquake resistant techniques was evaluated by subjecting the soil-structure system into three different earthquake loadings (two actual earthquake records and one synthetic earthquake), and measuring the respective responses. The results demonstrated that the seismic load against the caisson quay wall could be substantially reduced using the proposed technique. In addition, the presence of the protective tire chips cushion could significantly reduce the earthquake-induced residual displacement of the caisson quay wall.

Design input earthquake motions considering influence of characteristics of earthquake source fault and soil deposit are being used in seismic design of structures in recent years. It is becoming necessary to examine the behavior of the structure under ground motions with period and duration property which had hardly been taken into consideration. A series of gravitational and centrifugal model tests was conducted in this study, to investigate influence of long-period and long-duration earthquake motion on gravity type quay walls. Applicability of the finite element analysis, FLIP, to long-period and long-duration earthquake motions is examined by comparing the results of analysis and tests.

多数のセンサ・ノードを用いたネットワークセンシングは新しい計測手法として注目されている．本論文では，このネットワークセンシング技術を社会基盤センシングに適用する際の方向のひとつとして，階層型センサネットワークシステムの利用を提案する．センサネットワークを実際の計測に適用する際の最重要課題，「センサ間の時刻同期」と「個々のセンサの位置同定」の問題のうち，本論文ではシステムの実装の具体例として位置同定の問題を取り上げ，階層型の位置同定手法について述べる．この手法では音響測距とスケーラブルなアルゴリズムを用いて相対位置を推定された多数の末端ノード群に安価なGPSによる数センチメートル精度の絶対位置リファレンスが与えられる．

This paper reports an investigation on liquefaction experiment site. In the experiment, surface deformation and FWD deflection were measured on asphalt and concrete pavements which were on improved ground for liquefaction or unimproved one. The result showed that difference of elevation between pavement on improved ground and unimproved one were approximately 30 cm at most. The transformation of surface deformation continued for only a few hours. FWD deflection just after liquefaction exceeded that before liquefaction, and deflection kept decreasing for about seven day

The role of Airport during and after large earthquake is important as assist emergency medical service, stating special operation for transporting living necessities for suffers' daily life immediately and restarting commercial logistic operation to support the activities of the enterprises located around the airport. Full-scale experiment using controlled blasting was conducted in the Ishikari Bay New Port (Ishikariwan-shinko) in Hokkaido Island, Japan, to assess the performance of airport facilities subjected to the liquefaction. Airport facilities in this study included runway pavement with full specifications for B747 aircraft and apron pavement with/without countermeasures for liquefaction, air traffic control facilities such as the Glide Slope Antenna, the Localizer Antenna, drainage conduit and etc. This paper presents that the earthquake resistance improvement strategy and some of the test results while the measurement and investigation are progressing now.

It is known that “Blast Densification Method” is a technique which can improve the ground strength for the liquefaction by the artificial trembling with the shock wave of explosives detonation set in ground. It is carried out a full scale test which has the airport facility at Ishikari Bay New Port in Hokkaido Island, Japan.The shaking by blasting continues for about two minutes, with 1769kg explosives, 583 delay numbers, at about 1.6 hectares experiments. It is executed safely, surely without damage to structures by blasting.As a result of the experiment, it is confirmed the increasing excess pore water pressure, sand pumping phenomenon, and settlements after basting. This report is described a summary of experiment on this test

本文では，ジオグリッドで補強した固化処理地盤の耐震性評価のための動的有限要素法を提案する．提案する解析法は，固化処理地盤の解析に適した粒状離散化有限要素法と，飽和地盤の解析に適した土－水連成型有限要素法とを混合して問題を解く．解析法の妥当性を検証するために，3ケースの水中振動台実験をシミュレートした．解析は実験で計測された模型の挙動をうまく再現できることを明らかにする．

Full-scale experiment using controlled blasting was conducted in the Ishikari Bay New Port (Ishikariwan-shinko) in Hokkaido Island, Japan, to assess the performance of airport facilities subjected to the liquefaction. This paper mainly describes effect of liquefaction remediation and behavior of runway pavement during and after liquefaction by optical fiber monitoring.As a result of Full-scale experiment, a lot of valuable knowledge was obtained. Especially three types of tried liquefaction remediation with cost reduction deign specification are effective. Additionally optical fiber sensor shows high possibility for utilization as a runway pavement performance monitor because its deformation induced by liquefaction could be measured.

Two full-scale experiments using controlled blasting were conducted in the Port of Tokachi on Hokkaido Island, Japan, to assess the behavior of a single pile, a four-pile group, and a nine-pile group subjected to lateral spreading. The test piles were extensively instrumented with strain gauges to measure the distribution of bending moment during lateral spreading which allowed the backcalculation of the loading conditions, as well as the assessment of damage and performance of the piles. Based on the test results, it was concluded that using controlled blasting successfully liquefied the soil, and subsequently induced lateral spreading in the 4–6% surface slope test beds. The free-field soil displacements in the vicinity of the test piles were over 40 cm for both tests. When compared with the results from the single pile case, the effect of pile head restraint from the pile cap improved overall pile performance by decreasing the displacement of the pile groups and lowering the maximum moments in individu...

This study proposes a method for designing the bottom slabs of composite caisson breakwaters considering the unevenness of rubble mound surfaces. Based on the results of large-scale model tests, we developed a stochastic model to represent the distributions of reactions acting on the bottom slabs of caissons. We then conducted reliability analyses on the model to calculate the bending failure probabilities of the bottom slabs with respect to the mound unevenness. We also evaluated the partial factors to be used in designing the bottom slabs of caissons at various degrees of mound unevenness.

Floating structures in water generally have better characteristics in respect to seismic resistance. Because of the few studies on actual floating bridges, there are still some aspects concerning seismic response characteristics that remain unclear. This report studied structural behavior under seismic conditions of a floating bridge that was anchored with submarine cable, a newly conceived system, by conducting underwater vibration experiments and numerical analysis.As the floating bridge used in the research was comparatively flexibly anchored with submarine cable it has a long-period structure. When the behavior under seismic conditions of this structure was investigated and analyzed, the floating bridge with long-period structure and with submarine cable had less of a response acceleration than a conventional short-period type fixed bridge, and therefore had better seismic resistance characteristics.

The container crane of the harbor received the enormous damage in the Hyogo-ken Nanbu earthquake disaster. After that, the container crane with seismic vibration isolation system has been developed and operated in practical use. In this study, a rocking type of vibration isolation system (RVIS) was proposed for the container crane. And the experiment of the scale model was performed to verify the analytical model. From the results of the experiment and the analysis for the scale model, the validity of the model was demonstrated. The influence on the quay structure which is excited by the load of the container crane was made clear. The results of the RVIS showed better performance to reduce the load to the quay structure than the conventional container crane.

It is well known that the port facilities in Kobe Port suffered severe damages during the 1995 Hyogoken-Nambu earthquake. Especially, many caisson type quay walls were damaged during the earthquake. In order to mitigate hazards and losses due to earthquakes, seismic design methodologies have been developed and revised after each past earthquake event. The design practice of port structures in Japan introduced a performance based design concept as a result of damage investigations after the 1995 Hyogoken-Nambu earthquake. The restoration of Kobe Port was based on following philosophies: 1) quick recovery of the functions of the port, 2) improve seismic performance, 3) renewal with change the function of facilities and 4) continued operation of the port during restore works.

As a result of the Kobe disaster in 1995, new analysis methods including the effective-stress analysis for quay walls and pushover analysis for pile-supported wharves are introduced in the technical standards for port and harbour facilities in Japan to assess seismic performance of structures beyond the limit of force balance. In this article, design practice of port structures in Japan is described, with focuses on these new analysis methods. Some of the problems to be solved are also briefly described.

In this study, we conducted a series of loading tests to investigate load support systems of a rubble rock foundation supporting a breakwater caisson. The test results show that the loading block is supported by a small number of contact points and the contact forces have a wide range of distribution. This discrete and inhomogeneous load support system of the foundation is very different from linearly distributed load support system assumed in the current design. As a result, the bottom slab of a caisson has larger bending moments than those predicted by linearly distributed load. The test results do not show a dependence of the load support system on the foundation surface roughness made by expert divers.

本報告は, RTK-GPSを用いた大規模な地盤変状の計測の可能性を検討したものである. これは, 地震時の液状化時等に発生しうる広範囲な地盤の大変状に対し, リアルタイム性と十分な計測精度を確保して計測する手法の候補である. 人工的に引き起こされた液状化による地盤変状を10台のGPS受信機を用いて計測し, トータルステーションや画像解析による計測結果の比較によって計測精度を評価した. 堅牢性には大きな問題はなく, 残留変位を測る静的計測精度や, 変状中の変位を測る動的計測精度も, 地盤大変状の検知には十分であった. 検討結果はRTK-GPSを用いた地盤大変状の計測の実用性を示すものである.

平成7年兵庫県南部地震において, 大きな被災を受けた神戸港の鋼管杭式縦桟橋, 横桟橋およびドルフィンについて現地調査, 被災メカニズムに関する解析を行った.桟橋の被害調査の結果により, 鋼管杭式桟橋の被害は周辺地盤の側方移動に起因していることが明らかになった. また, 静的な弾塑性解析により桟橋の被災メカニズムが定性的に説明が可能であるが, 絶対変位量まで含めて評価するためには, 非線形動的解析モデルが有効であることがわかった. さらに, 桟橋の水中振動台模型実験により, 側方移動をともなう横桟橋の残留変形がある程度再現可能であることがわかった.

This paper shows the effects of the stiffness of an underlying soft clay layer on the strong motion response. Seismic behavior of Kobe's artificial islands during the 1995 Hyogo-ken Nambu earthquake is studied by centrifuge shaking table test. During the earthquake, it is known that the liquefaction damage on artificial islands was different at each site. The authors consider that this is due to the stiffness of the clay layer underlying the reclaimed ground because of the degree of consolidation. The model grounds used for the centrifuge test were made with clay and fill material sampled from Kobe Port Island, and the clay material was consolidated at two different degrees of consolidation, which correspond to those of the Port Island array observation site and the south-western part of Rokko Island. First, from the viewpoint of the reproducibility of in-situ behavior, we compared the seismic response and the ground settlement obtained from centrifuge test with those of the observation data of Port Island. Next, we compared the seismic response of the test results of the different degree of consolidation. It is found that the difference of stiffness due to the degree of consolidation of the underlying clay layer significantly affects the seismic behavior of reclaimed ground. The large damage is not always come to being on the ground with soft clay layer.

斜杭式桟橋の模型振動実験を実施し, 地震時の上部工の応答特性, 杭断面力に対する地盤変位の影響について検討した. 模型製作にあたっては, 杭の軸剛性と曲げ剛性, 地盤剛性に関して相似性を持たせ, 実験は4種類の異なる地盤と2種類の異なる上載荷重条件で行った. その結果, 斜杭式桟橋は, 基盤からの入力が支配的であり, 直杭式桟橋と異なった振動特性を示した. 斜杭に発生する軸力は, 上部工の応答により決定し, 地盤の動きは, 杭頭曲げモーメントに大きく影響を及ぼした.

System identification (SI) methods are used to determine empirical Green's functions (EGF) for soil intervals at the Port Island Site in Kobe, Japan and in shake table model tests performed by the Port and Harbor Research Institute (PHRI) to emulate the site during the 17 January 1995 Hyogo-ken Nanbu earthquake. The model form for the EGFs is a parametric auto-regressive moving average (ARMA) model mapping the ground motions recorded at the base of a soil interval to the top of that interval, hence capturing the effect of the soil on the through-passing wave. The consistency of site response at Port Island before, during, and after the mainshock is examined by application of small motion foreshock EGFs to incoming ground motions over these time intervals. The prediction errors (or misfits) for the foreshocks, the mainshock, and the aftershocks, are assessed to determine the extent of altered soil response as a result of liquefaction of the ground during the mainshock. In addition, the consistency of soil response between field and model test is verified by application of EGFs calculated from the shake table test to the 17 January input data. The prediction error is then used to assess the consistency of behaviour between the two cases. By using EGFs developed for small-amplitude foreshock ground motions, ground motions were predicted for all intervals of the vertical array except those that liquefied with small error. Analysis of the post-liquefied ground conditions implies that the site response gradually returns to a pre-earthquake state. Site behaviour is found to be consistent between foreshocks and the mainshock for the native ground (below 16 m in the field) with a normalized mean square error (NMSE) of 0.080 and a peak ground acceleration (PGA) of 0.5g. When the soil actually liquefies (change of state), recursive models are needed to track the variable soil behaviour for the remainder of the shaking. The recursive models are shown to demonstrate consistency between the shake table tests and the field with a NMSE of 0.102 for the 16 m to surface interval that liquefied. The aftershock ground response was not modelled well with the foreshock EGF immediately after the mainshock (NMSE ranging from 0.37 to 0.92). One month after the mainshock, the prediction error from the foreshock modeled was back to the foreshock error level. Copyright © 2001 John Wiley Sons, Ltd.

コンテナ埠頭岸壁等に設置されるコンテナクレーンの地震時の挙動として, 脱輪現象が兵庫県南部地震等で確認されている. コンテナクレーンは構造形式により脱輪を起こすと転倒することも確認されている. また, 脱輪を起こさない場合でも脚部の変形・座屈により使用不能となった例が多い. 一方, クレーンを有する岸壁基礎に対しても地震時にクレーン荷重の与える影響は大きいものと推測され, さらに, クレーンが脱輪する場合はその衝撃荷重が作用するものと考えられる. そこで, 本研究では1/15縮小模型による振動台実験を行い, 地震時のクレーン脱輪現象等の影響を確認したうえでコンテナクレーンの免震化を提案し, クレーン本体, クレーン基礎に対する耐震性能の向上を確認した.

Currently, the seismic design method of a container crane is adopted the 'seismic coefficient method'(pseudo static method). In case of extremely high intensity input seismic motion such as Level 2, the dynamic behavior of a container crane is expressed in terms of lift off of the legs from the rails and locking motion. The current design method can not treat the behaviors mentioned above. To evaluate and develop the design method for the Level 2 input motion, 1/15 scale model shake tsets, simple mass-spring numerical analyses and 3-D dynamic FEM analyses were conducted. From the model shake test results, a threshold acceleration level of the lift off of the legs from the rails showed good agreement with a pseudo static horizontal acceleration of lift off the legs predicted in the design method. Proposed 3-D FEM model of container crane can simulate the dynamic behavior of a crane model during a shake table test even when the legs lifted off from the rails. The simple mass-spring model is also a useful numerical method for the case of smaller acceleration level when the legs do not lift off.