摘要
通过桩身埋设有钢筋应力计的2根直径不同的破坏性和非破坏性后注浆抗压试桩现场静载试验,对比分析了破坏性和非破坏性后注浆抗压试桩的受力性状。现场试验表明,极限荷载下非破坏性和破坏性后注浆桩的桩端力荷载分担比约为40%且同一桩顶荷载水平下,桩端荷载分担比随桩径的增大而减小。最大试验荷载下非破坏性试桩浅层土侧阻力完全发挥并有侧阻软化趋势,而破坏性试桩全桩长范围桩侧阻力均表现为软化性状。实测发现不同土中桩侧摩阻力充分发挥时对应的桩顶沉降约为(1%～4%)D(D为桩径)。非破坏性试桩实测得到的桩端位移–桩端力曲线表现为硬化特性,而试桩破坏性试验中实测得到的桩端位移–桩端力曲线表现为软化特性。
Field tests on the behaviors of one destructive base-grouting pile and one non-destructive base-grouting pile under compression are presented.The two piles have different diameters and are instrumented with rebar strain gauges along the pile shafts.The results of these full-scale loading tests show that the ratio of the tip load to the pile head load of the destructive and the non-destructive base-grouting piles is about 40% at the capacity load level,and it decreases with the increase of pile diameter at the same load level.Furthermore,at shallow depth the skin friction of the non-destructive pile decreases from the ultimate skin resistance with the increase of load as the test pile is loaded to the maximum value,whereas for the destructive pile the shaft resistance along the pile depth approaches to the limiting state and decreases from a peak value with further increase of the pile head load.The thresholds of settlement at the pile head for fully mobilizing the skin resistances in different soils are about 1% to 4% of the pile diameter.The load transmission curve of the soils around the pile base corresponds to a softening model in the field tests on the destructive pile,whereas the settlement-resistance curve of the non-destructive pile developed at the pile tip follows a hardening model.
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2011年第10期1601-1608,共8页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金项目(51078330)
关键词
非破坏性试桩
破坏性试桩
后注浆技术
桩侧阻力
桩端阻力
non-destructive pile
destructive pile
base-grouting technique
skin friction
tip resistance
