静力触探CPT在水力吹填砂土地基承载力评估中的应用

为了更好控制科威特LNGI工程水力吹填砂土地基质量,合理评估水力吹填砂土地基处理后的承载力,选取基于CPT的3种经验公式,计算满足设计承载力200 kPa作用下所需的最小锥尖阻力qc值。结果显示,Bowles(1996)法和BS EN1997-1:2004 Annex D推荐法计算的最小qc值与水力吹填质量等级有关,但两者结果较接近,而EslaamizaadRobertson(1996)法计算的结果较小,仅为3. 8 MPa。基于保守考虑,最终结果取前两种方法平均值中的最大值7. 5 MPa。同时基于现场实际,在地基处理后预先进行CPT检测,得到平均锥尖阻力远大于计算验收值,并由大型载荷板ZLT试验验证了满足长期沉降的设计承载力。可见,在地基处理后可预先采用CPT对处理后地基处理承载力进行评估并辅助少量大型ZLT试验进行验证,可有效对地基承载力进行验收。

Application of cone penetration test in the bearing capacity assessment in hydraulic sandy fill

In order to better control the quality of the Kuwaiti LNGI engineering dredger fill sandy soil foundation,and rationally evaluate the bearing capacity of the hydraulic blown sand soil foundation after treatment,three empirical formulas based on CPT are selected,and the qc value of the minimum cone tip resistance required under the action of 200 kPa of designed bearing capacity is calculated.The results showed that the minimum qc values calculated by the Bowles(1996)method and BS EN 1997-1:04 Annex D recommendation method are related to the hydraulic filling quality grade,but the results are close,while the results calculated by Eslaamizaad & Robertson(1996) method are smaller,only 3.8 MPa.Based on conservative consideration,the final result takes the maximum of 7.5 MPa in the average value of the previous two methods.At the same time,CPT test is carried out in advance after foundation treatment,and the average cone tip resistance is much higher than the calculated acceptance value.It can be seen that after the foundation treatment,the foundation treatment bearing capacity can be evaluated by CPT in advance and verified by a small number of large ZLT tests,so that the foundation bearing capacity can be checked effectively.