由于应力释放引起的深水土样扰动性研究(英文)

从深水海底取得的土样要经受很大的应力释放。模拟孔隙水中溶解有不同含量气体的深水黏土取样过程 ,对Lierstranda黏土进行了一系列三轴和高压固结试验。试验结果表明 ,自重应力下的孔隙比变化与孔隙水中的气体饱和度 η 成线性增长关系。其它测得的土性参数 ,如不排水强度、峰值应力下的应变、剪胀系数和先期固结压力等均随着 η 有规律地变化 ,显示土样的扰动性也随着 η 的增加而增加。据此 ,本文提出了对可能含有气体的深水土样的最佳贮藏与处置方案。

Deepwater sample disturbance due to stress relief

Samples taken from seabed soils in deep water are subjected to a large stress relief. This paper presents the comprehensive study results of laboratory tests where deepwater sampling of clay with various amounts of gas dissolved in the pore water has been simulated. Measurements in triaxial and oedometer tests on Lierstranda clays show that the change in void ratio increases linearly with degree of gas saturation η,when reconsolidated to in situ stresses.Other measured parameters, like undrained shear strength, strain under peak shear stress, dilatancy parameter and preconsolidation stress, also vary systematically with η, showing that disturbance increases with η.The results obtained from the tests have been used to develop recommendations for optimal procedures to store and handle samples containing gas.