|
■■■■■■■■■■■■■■■■■■■ 川崎製鉄技報 KAWASAKI STEEL GIHO Vol.7 (1975) No.3 ■■■■■■■■■■■■■■■■■■■ |
| 2重壁鋼矢板工法の振動特性に関する実験的研究 Experimental Study on Vibrational Properties of Double Sheet-piled Wall Structure 高橋 千代丸(Chiyomaru Takahashi) 石田 昌弘(Masahiro Ishida) 三好 弘高(Hirotaka Miyoshi) |
| 要旨 : ２重壁鋼矢板構造に関する耐震設計法の確立までにはいまだ多くの解明すべき課題が残されている。本研究では，本構造物の動的特性を定常的正弦波およびランダム波試験により実験的に追求した。実験に使用した模型矢板にはアルミ板を，模型地盤には乾燥砂を用い，実験は締切タイプおよび護岸タイプの2種類について実施した。その結果，両タイプとも振動後の残留値は振動時の値と比較するときわめて大きい。締切タイプでは矢板の最大曲げモーメント，土圧およびタイロッド張力は現設計法による設計値よりも安全側の値を示すが，矢板変位は矢板剛性が小さい場合に設計値を上廻る。加速度特性から締切タイプでは矢板と中詰砂とを連続体とし，護岸タイプでは地盤と本構造体の連成振動系とすべきことが判明した。 |
| Synopsis : There are many problems yet to be solved about the aseismic design of double sheet-piled wall structure. This report deals with experiments on the response of this structure subject to various modes of loading such as static, stationary harmonic and random excitations. Model surface layers used in the experiments are composed with dry sand. Vibrating tests are performed on cofferdam type and bulkhead type models. The cofferdam type is a structure with filling only and the bulkhead type together with backfilling. The dynamic behavior of this structure subjected to excitations is investigated with particular emphasis on rigidity of sheet piles and the ratio of breadth to wall height. The results of this experiments revealed as follows. (1) Maximum bending moment of sheet-pile and tie rods tension are lower than the design values by the existing method regardless of rigidity of sheet-piles. (2) In the case of low sheet-pile rigidity, the experimental value of maximum deflection by far exceeds the design value. However, the experimental value shows a tendency to come close to the design value with an increase in sheet-pile rigidity and a lowering of input acceleration. (3) The experimental value of earth pressure is below the design value and the form of its distribution becomes nearly rectangular with repetition of excitations. (4) Response acceleration at the top of front sheet-pile in the case of the cofferdam type is about seven times as much as the input value. On the other hand, in the case of the bulkhead type, its value is a little higher than in the cofferdam type. In discussing dynamic characteristics of soil-foundation system based on the above results, it is necessary to consider the effects of virtual mass of ground soil. (5) The relationship between response ratio and input acceleration shows that the spring constant of soil has linear properties in the cofferdam type and non-linear properties in the bulkhead type. |
| 本文（PDF: 17P/723kb） |