Effect of intergranular friction on soft-sedimrnt deformation

粒间摩擦对软沉积物变形的影响

• 批准号: 16540418
• 负责人: MIYATA Yuichiro
• 金额: $ 1.98万
• 依托单位: Yamaguchi University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16540418/
• 关键词: soft-sediments; failure style; intergranular friction; singing sand; grain surface; 安息角; スティックスリップ; ストレスチェーン; 歪の局所化

This study focused on the intergranular friction as a major factor contralling the deformation style of soft-sediments. In order to verify this problem, material with different intergranular friction but with the same physical properties other than the friction is needed. The singing sand is one of such material, because they show higher friction than usual sands, and had been changed due to long-term polish under water. In the same way, we can change the friction property of sands in laboratory. Various kinds of physical properties were examined, such as porosity, angle of repose of sand slope, angle of shear resistance, and vane-shear strength for variously posished sands both in air and in water. The deformatin styles were also examined under shear both in air and in water, including the condition of sound producing. As the results ;(1)The intergranular friction becomes higher in enough polished sands for singing, probably because of intermolecular force including pressure solution at grain contact, as shown by the above physical properties of the dry singing sands.(2)The intergranular friction becomes lower in sufficiently sands with very smooth grain-surfane, especially under water.(3)Puzzling high shear-resistance shown by singing sands under water regardless of low friction may be explained as caused by dense packing (higher coordination number) realized by lower intergranular friction.(4)The incipient failure in a singing sand layer under water may show a different deformation style from dry singing sands with apparent slip plane and from usual sands with ductile deformation when applied lower stress.The stress-strain relationship as well as deformation style is, therefore, stlongly affected by intergranular friction.

本研究重点关注粒间摩擦力作为控制软沉积物变形方式的主要因素。为了验证这个问题，需要具有不同晶间摩擦力但除摩擦力外物理性质相同的材料。鸣沙就是其中一种材料，因为它们比普通的沙子具有更高的摩擦力，并且由于长期在水下抛光而发生了变化。同样，我们可以在实验室中改变沙子的摩擦特性。对各种抛光砂在空气和水中的各种物理性质进行了检查，例如孔隙率、砂坡休止角、抗剪角和叶片剪切强度。还在空气和水中的剪切力下检查了变形样式，包括发声情况。结果;(1)在足够的磨光砂中，粒间摩擦力变得更高，可能是由于分子间力，包括颗粒接触处的压力溶液，如干砂的上述物理性质所示。(2)粒间摩擦力在具有非常光滑的颗粒表面的足够的沙子中，特别是在水下，该剪切力变得较低。（3）无论摩擦力如何，水下歌唱沙子所表现出的令人困惑的高剪切阻力可以解释为由通过以下方式实现的密集堆积（更高的配位数）引起的(4)当施加较低的应力时，水下的歌唱砂层的早期破坏可能表现出与具有明显滑移面的干燥歌唱砂和具有延性变形的普通砂不同的变形风格。应力-应变关系也是如此因此，变形方式受晶间摩擦力的影响很大。