摘要
深厚卵石地层的钻探或桩基施工,会面临钻头磨损剧烈、钻进效率低、孔壁坍塌、排渣或取芯困难等问题。详细查明卵石地层颗粒级配及粗颗粒强度特性并进行正确的评价,是卵石地层桩基施工成败的关键性工作。以吉利黄河特大桥深厚卵石层的勘察和桩基施工为例,分析了卵石地层钻探手段的有效性及其对桩基成孔的影响,提供了深厚卵石层桩基侧摩阻力、桩端承载力取值及桩基施工方面的建议。
Drilling for the geotechnical borehole or for the piled foundation in thick cobble soils will frequently encounter difficulties, such as, severe drill bit wearing, low drilling rate, borehole instability, difficult in drill waste or rock core removal. Properly and accurately characterizing the grain size distribution and geotechnical properties are critical to the success of piled foundations in the cobble soils. This paper presents a case history of geotechnical investigations and cast-in-place pile installation in thick cobble soils for the Jili Yellow River Crossing Bridge. The effectiveness of drilling technique and borehole stability in the thick cobble soils layers are evaluated. Suggestions for the end bearing, side frictions of pile and pile installations in cobble soils are also provided in the paper.
作者
高清材
张国超
GAO Qingcai;ZHANG Guochao(China Railway Major Bridge Reconnaissance&Design Institute Co.,Ltd.,Wuhan 430050)
出处
《土工基础》
2020年第2期140-144,共5页
Soil Engineering and Foundation
关键词
桥梁基础
深厚卵石层
工程勘察
桩基施工
bridge foundations
cobble soils
geotechnical investigations
piled foundation constructions
