摘要
通过西北地区两起地基事故的分析,找出了黄土状盐渍土地区事故的内因是地基土中含有易溶盐,外因则是水的渗入。由于渗水或地下水位上升,浸泡了地基,溶解了盐类,导致地基土溶陷,基础下沉、墙体开裂;或者毛细水携带盐类上升,浸入基础和墙身,在适宜的温度下,硫酸盐结晶隆胀,对墙基产生破坏作用。提出了对盐渍土地基处理的最根本的措施是防止水份渗入地基和基础,阻止含盐水份的浸入和渗出。为保障设计人员正确运用规范,全面考虑设计措施,恰当地进行地基处理,杜绝事故的发生,对土的定名要慎重、准确。对于易溶盐含量超过0.3％的黄土状土应定名为“黄土状盐渍土”,以全面表达土的工程性能。盐渍土在三大内陆盆地分布面积甚广,而它的胶结恰似坚实的假象,往往被误认为是良好的天然地基,使一些建设单位不做地基处理就进行工程建设,结果渗水引起地基事故,目前我国还没有制定盐渍土地区的建筑技术规定,建议有关部门组织编制。
Through analysis on the two foundation accidents which took place in China Northwestern area, both the internal and the external factors are found out, the former was the fusible salt content in the foundation soil, the latter was the water permeeting. The permeeting and underground water increased in level, soaked the foundation, and melted the salt and the alike thus resulting in the foundation soil melting and sinking, the foundation settling and wall cracking; The other possible reason why the wall foundation can be damaged was that the level of salt and the alike carried by capillery water, increased and sank into the foundation and the wall, and the sulphate crystal out of it expanded under suitable temperature. The writer points out in the paper that the foundamental measure of treating the foundation of saliferous clay is to prevent water from permeeting into the foundation, prevent water with salt content from permeeting in and out. The defination of the soil should be correct enough in order to guarantee the designers's correct usage of codes/standards,determination of design measures with all factors taken into account, and correct measures of treating the foundation and put an end to such accidents. The loess, the fusible salt content of which exceeds 0. 3%, should be named 'Saliferous clay of loess type' so as to describe the engineering characteristics of the soil of this kind in a comprehensive way. There are large areas of saliferous clay in the main three inland basins. It is usually mistaken as a kind of good and natural foundation for its cementation degree, which makes construction companies start their project construction without any foundation treatment, thus causing accidents due to water permeeting. There has not been any codes/standevels, so far, in China for constructions in saliferous clay areas. Concerning organizations are suggested to start working out codes/standards of this kind.
出处
《油气储运》
CAS
北大核心
1995年第2期42-46,共5页
Oil & Gas Storage and Transportation
关键词
地基基础
事故分析
盐渍土
黄土
foundation , crack, code/standard, cementation, salt, permeet
