权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

FUNDAMENTAL STUDY ON THE MITIGATION OF LIQUEFACTION INDUCED DISASTER BY INJECTING AIR BUBLLES IN THE GROUND

地下注入气泡减轻液化灾害的基础研究

基本信息

批准号：
18560490
负责人：
HATANAKA Munenori
金额：
$ 2.48万
依托单位：
Chiba Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18560490/
关键词：
sandy soils countermeasure to liquefaction degree of saturation relative density P-wave velocity liquefaction strength roundness air bublle 物理特性

项目摘要

A series of laboratory tests were performed in order to investigate the effects of the size and the roundness of soil particles, relative density, and air bubbles involved in the pore water of sandy soils on the relationship between the degree of saturation (Sr) and the P-wave velocity (V_p). The effect of degree of saturation on the liquefaction strength of sand was studied both on the undisturbed and reconstituted samples. The methods to generate air bubble and to insert the air bubble into the ground were also studied using model sand ground.Following were concluded : (1) Unlike the effect of the size of soil particles of sand on the B-value-V_p relationship, its effect on the Sr-V_p relationship is small. The P-wave velocity increases rapidly with increasing degree of saturation from 90 % to 100 % for all sands tested ; (2) The effects of relative density on the Sr-V_p relationship are negligible ; (3) The effects of air bubbles involved in pore water both on B-value-V_p relationship and Sr-V_p relationship are significant ; (4) By comparing the liquefaction strengths obtained in the undrained cyclic triaxial tests on Futtsu sand, the method to decrease the degree of saturation by injecting the air bubbles into the sandy ground is expected to be a useful method to decrease the disasters induced by the sand liquefaction. (5) A simple method to unsaturate sand ground was successfully performed based on model ground test by inserting air bubble dissolved water into the ground under some water head.

为了研究砂质土孔隙水的颗粒大小和圆度、相对密度和气泡对饱和度Sr和纵波速度V_p关系的影响，进行了一系列室内试验。研究了饱和度对原状砂土和原状砂土液化强度的影响。利用模型砂土，研究了气泡的产生和气泡的插入方法。结果表明：(1)不同于砂土颗粒大小对b值- v_p关系的影响，其对Sr-V_p关系的影响较小。纵波速度随饱和度的增加而迅速增加，所有测试砂的饱和度从90%增加到100%；(2)相对密度对Sr-V_p关系的影响可以忽略不计；(3)孔隙水中气泡对B-value-V_p关系和Sr-V_p关系的影响均显著；(4)通过对扶桑砂土不排水循环三轴试验液化强度的比较，认为通过向砂土地面注入气泡降低饱和程度的方法有望成为减少砂土液化灾害的有效方法。(5)在模型地基试验的基础上，成功地提出了一种简单的非饱和砂土地基处理方法，即在一定水头下向地基注入气泡溶解水。