Utilization of unconfined compression strength --- Correction of stress reliese and disturbance in unconfined compression tests ---

无侧限压缩强度的利用——无侧限压缩试验中应力依赖和扰动的修正——

• 批准号: 62850092
• 负责人: OHTA Hideki
• 金额: $ 1.28万
• 依托单位: Kanazawa University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Developmental Scientific Research
• 财政年份: 1987
• 资助国家: 日本
• 起止时间: 1987 至 1988
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-62850092/
• 关键词: Unconfined compression strength; Undrained strength; Soft clay; Residual effective stress; Undisturbed sample; 円弧すべり法

Effective stress state of "undisturbed samples" collected from all over japan was investigated aiming at estimating the residual effective stress in the samples after experiencing sampling, trimming and being ready to be subjected to unconfined compression tests. The undrained strength mobilized along the slip circles was theoreticall derived. The average undrained strength along the slip circle being compared with the corrected unconfined compression strength indicated the appropriateness and the limitation of the usage of unconfined compression strength in the stability analysis of soft clay foundations. The backanalysis of 24 case histories of actual failure of soft clay showed a reasonable agreement with the results obtained from the investigation on unconfined compression strength. the conclusions are as follows:1. The effect of sample disturbance and stress release corresponds to within 0.1 in terms of the factor of safety.2. The effect of loading rate in the field corresponds to about 0.2 in terms of the factor of safety. This indicates that the selection of construction method and construction sequence is more influencial to the stability of soft foundations rather than the degree of sample disturbance is.3. The correction factor to be multiplied with the experimentally obtained unconfined compression strength in analysing the stability of soft clays is derived as a function of the plasticity index.

对从日本各地收集的“未扰动试样”的有效应力状态进行了调查，目的是估计试样在经过取样、修整和准备进行无侧限压缩试验后的残余有效应力。从理论上推导了沿滑移圈动员的不排水强度。将沿滑圈的平均不排水强度与修正后的无侧限抗压强度进行比较，表明了无侧限抗压强度在软土基础稳定性分析中的适用性和局限性。对24例软粘土的实际破坏历史进行反分析，结果与无侧限抗压强度研究结果吻合较好。研究结论如下：1。试样扰动和应力释放对安全系数的影响在0.1以内。加载速率对现场安全系数的影响约为0.2。这表明施工方法和施工顺序的选择对软基稳定性的影响大于对试样扰动程度的影响。导出了在分析软粘土稳定性时，与试验得到的无侧限抗压强度相乘的修正系数作为塑性指数的函数。

项目成果

太田秀樹: サンプリングシンポジウム論文集. 35-40 (1989)

Hideki Ota：采样研讨会论文集 35-40 (1989)。

Hideki,Ohta: "Residual effective stress in "undisturbed" samples" Proc. Sampling Symposium. 35-40 (1989)

Hideki，Ohta：““未受干扰”样品中的残余有效应力”Proc。

太田秀樹: 土木学会論文集. 400/III-10. 45-54 (1988)

Hideki Ota：日本土木工程师学会会议记录 400/III-10 (1988)。

Koki,Matsumoto: "Analysis of behaviour of soft clay ground during excavation and embankment in a waterfront reclaimed land." Proc. 33rd Symposium on Soil Engineering --- Geotechnical Problems in Waterfront Development ---. 117-122 (1988)

Koki，Matsumoto：“滨水区开挖和筑堤过程中软粘土地基性能分析。”

松本江基: 第33回土質工学シンポジウム論文集-ウォーターフロント開発における土質工学上の諸問題-. 117-122 (1988)

Eki Matsumoto：第 33 届土壤工程研讨会论文集 - 滨水区开发中的土壤工程问题 117-122 (1988)。