Investigations of the Residual Settlement of Reclamation Dikes and its Prediction Mmethods for the Introduction of Performance Based Design to the Maintenance of Reclamation Dikes

填海堤残余沉降的研究及其预测方法在填海堤维护中引入基于性能的设计

基本信息

批准号：
15580215
负责人：
HIGASHI Takahiro
金额：
$ 2.43万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

In the case of Ariake reclamation dike (Saga Pref.), because there was no local difference in both the soil layer composition and the soil properties of the foundation ground, a local difference was not recognized for the residual settlement behavior due to the wave dissipating concrete block establishment. But a local remarkable difference was seen for the ground subsidence in the drought in 1994. On the other hand, in the case of Yokoshima reclamation dike (Kumamoto Pref.) because both the soil layer composition and the soil properties of the foundation ground greatly varied in the area, the difference in the local settlement tendency was remarkable.The following main results about the mechanical properties of Ariake clays were obtained : (1)The Hvorslev's strength parameters of Ariake clays were naturally dependent on grain size distribution. (2)The irreversibility ratio (∧) of Ariake clays was in the range of 0.6〜0.8 and was independent on both grain size distribution and plasticity index. (3)The compression index (C_c) of Ariake clays was strongly dependent on the natural void ratio. (4)The consolidation yield stress (p_c) obtained from the consolidation test using constant rate of strain loading was higher than that obtained from the consolidation test using incremental loading.It was concluded that the consolidation deformation analysis by elasto-plastic finite element method (FEM) was the most suitable as the residual settlement prediction method. However, considering the influence such as groundsubsidence at a drought, the complexity of the soil properties of the foundation ground and the reliability of the soil test data, and so on, the need and utility of the continuous field observation were strongly suggested after the maintenance of the reclamation dike.

在有明填海堤（佐贺县）的案例中，由于土层成分和地基土壤性质均不存在局部差异，因此未发现由于波浪消散而导致的残余沉降行为的局部差异。但在 1994 年的干旱中，地面沉降出现了局部显着差异。另一方面，在横岛填海堤（熊本县）的情况下，由于土层成分和区域内地基土性质差异较大，局部沉降趋势差异显着。关于有明粘土的力学性能，得到以下主要结果： (1)有明粘土的 Hvorslev 强度参数自然依赖于(2)有明粘土的不可逆性比(∧)在0.6〜0.8范围内，且与粒度分布和塑性指数无关。(3)压缩指数(C_c)。 (4)恒应变加载固结试验获得的固结屈服应力(p_c)高于增量加载固结试验获得的固结屈服应力(p_c)。弹塑性有限元法（FEM）固结变形分析最适合作为残余沉降预测方法，但考虑到干旱时地面沉降等影响、地基土性的复杂性和可靠性。土壤测试的填海堤维护后，强烈建议进行连续实地观测的必要性和实用性。