软弱地基土高能级强夯现场试验研究  

Field test on high energy-level dynamic compaction of soft foundation soil

作　　者：黄新连 HUANG Xinlian(China Railway Fifth Survey and Design Institute Group Co.,Ltd.,Beijing 102600,China)

机构地区：[1]中铁第五勘察设计院集团有限公司

出　　处：《石油工程建设》2019年第5期46-52,共7页Petroleum Engineering Construction

摘　　要：针对大型石油工程地基处理的复杂性,开展了15000、12000 kN·m两个高能级强夯的单点强夯和群夯的现场试验。利用旁压试验、标准贯入试验、静力触探试验结果,分析了施工前后地基承载力和土体工程特性变化情况;以平板载荷试验结果验证了地基的承载性能。研究结果表明:大面积施工时每遍夯击的击数宜控制在8~9击,2个能级强夯后有效消除了地面以下10、11 m左右范围内砂层液化的可能性;软弱夹层对强夯效果有明显的隔断效应,其影响起点为软弱夹层以上1 m左右;静载荷试验结果表明,2个能级强夯后地基承载力能达到设计要求,2个能级强夯有效加固深度均为11 m,有效加固深度修正系数比规范建议值略小。The foundation treatment of a certain large-scale petroleum engineering project is very complex.The in-situ tests of single-point and group-point dynamic compactions under high energy-levels of 15 000 and 12 000 kN·m were carried out.Based on the results of pressure meter test,standard penetration test and cone penetration test,the foundation bearing capacity change and soil engineering characteristics change before and after the dynamic compactions were analyzed,and the foundation bearing capacity was verified by loading test.Some conclusions have been drawn:the optimal number of strikes in every batch compaction should be 8 to 9 for large area construction;engineering characteristics of sand within 10 m and 11 m depth has been improved apparently after the compactions of the two high energy-levels.After dynamic compaction of the two energy levels,the possibility of liquefaction of sand layer in the range of about 10 m to 11 m below the ground is effectively eliminated;and the soft interlayer has obvious partition effect on the dynamic compaction result,and the starting point of the influence is about 1 m above the soft interlayer.The results of static load test show that the bearing capacity of the foundation after the two energy level dynamic compactions can meet the design requirements,the effective reinforcement depth of the two energy levels is 11 m,and the correction coefficient of the effective reinforcement depth is slightly smaller than that recommended values of relative specifications.

关 键 词：石化工程 软弱地基土 单点夯 群夯 高能级 现场试验 

分 类 号：TU4[建筑科学—土工工程]