THE MODELLING OF THE GENERATION AND DISSIPATION EXCESS POREWATER PRESSURE IN SEABED SEDIMENTS UNDER WAVE ACTIONS

波浪作用下海底沉积物超孔隙水压力的产生和消散模拟

• 批准号: 03650397
• 负责人: YASUHARA Kazuya
• 金额: $ 1.15万
• 依托单位: DEPARTMENT OF URBAN AND CIVIL ENGINEERING, SCHOOL OF ENGINEERING, IBARAKI UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1993
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-03650397/
• 关键词: Cohesive sediment; Pore water pressure; Wave action; Siltation; Settlement; Strength; Instability; 安定解析; 応力・ひずみ関係; 沈下; 支持力; 防波堤; 海底地盤; 波浪荷重; 過剰間隙水圧; 不安定; 底泥; 安定; シルテ-ション; 強度

The following subjects in the cohesive coastal sediments are included in the scope of the present research :1) Siltation induced by wave actions leading to the contamination of sea water as an important environmental problem for ports and harbors.2) Settlement and instability of breakwaters founded on soft normally consolidated clay.From the geotechnical point of view, a study of wave-induced cyclic loading and the associated effective stress regime in sediments is relevant to both of the above topics. To carry this out, the precise measurement or prediction of excess pore water pressures in coastal sediments is essential. The following conclusions were derived from a recent study :1) Based on the diffusion type of defferential equation including a term for sedimentation, a numerical model was established to evaluate the distribution of void ratio in coastal cohesive sediments under wave actions. The effect of interation between waves and silt was taken into consideration for the erosion flux. The numerical experiments were carried out under various intial conditions. The results indicate that the model is capable of predicting the approximate distribution and change of void ratio against depth during and after the sedimentation of silt.2) A model combined with Terzaghi's three dimensional consolidation theory and an empirical relation formulated from the results of undrained cyclic triaxial tests was proposed to predict the behavior of clay under partially drained cyclic triaxial tests as boundary value problem. It was also suggested that this model could estimate the long-term settlement and instability of a breakwater founded on cohesive seabed sediments under stormy conditions.

1)波浪作用引起的海水淤积是港口和港口的一个重要环境问题；2)基于软粘土的防波堤的沉降和失稳。从岩土工程的角度来看，研究波浪引起的循环荷载和与之相关的沉积物中的有效应力状态与上述两个问题都是相关的。要做到这一点，准确测量或预测海岸沉积物中的超孔隙水压力是至关重要的。1)基于含沉积项的扩散型微分方程组，建立了波浪作用下海岸粘性泥沙中孔隙率分布的数值模型。侵蚀通量考虑了波浪与泥沙相互作用的影响。在不同的初始条件下进行了数值实验。2)将太沙基三维固结理论与不排水循环三轴试验结果建立经验关系式，提出了一个结合太沙基三维固结理论的模型来预测部分排水循环三轴试验下粘土的特性。研究还表明，该模型可用于估算海床粘性沉积物上防波堤在暴风雨条件下的长期沉降和失稳情况。

项目成果

安原一哉: "繰返し荷重を受ける粘土の強度低下とその予測" 第28回土質工学研究発表会講演概要集Vol.1. Vol.1. 699-702 (1993)

Kazuya Yasuhara：“反复加载下粘土的强度下降和预测”第 28 届土壤工程研究会议摘要第 1 卷 1. 699-702 (1993)

安原 一哉: "長期繰返し荷重を受ける乱さない粘土の挙動" 土木学会論文報告集. 439/IIIー17. 9-16 (1991)

Kazuya Yasuhara：“长期循环荷载作用下的原状粘土的行为”，日本土木工程师学会论文集 439/III-16 (1991)。

佐藤研一 他: "An analysis of wave-induced settlement and pore pressure in seabed Clay" Proc.11th Southeast Asian Geotechnical Conference(第11回東南アジア土質工学会議録). 1. 475-480 (1993)

Kenichi Sato 等人：“海底粘土中波浪引起的沉降和孔隙压力的分析”Proc.11th 东南亚岩土工程会议 (1993)。

Hyodo, M., K.Yasuhara and K.Hirao: "Prediction of clay behavior in undrained and partially drained cyclic triaxial tests" Soils and Founda-tions. Vol.32, No.4. 117-127 (1992)

Hyodo, M.、K.Yasuhara 和 K.Hirao：“不排水和部分排水循环三轴试验中粘土行为的预测”土壤和基础。

Yasuhara, K.: "Post-cyclic degradation and recovery in undrained strenght in clay" Proc.13th Intn'1 Conf.SMFE. TC-4 Report Vo1. 143-148 (1994)

Yasuhara, K.：“粘土中不排水强度的循环后降解和恢复”Proc.13th Intn1 Conf.SMFE。