帽径比对铆钉桩受力性能影响的研究
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摘要
为研究帽径比对铆钉桩受力性能的影响,结合沿海公路改造工程,利用ABAQUS有限元建立了模型进行分析,研究了帽径比对桩顶应力分配、桩身应力变化和复合地基沉降的影响规律。研究结果表明:桩帽范围内的应力分布并不均匀,存在向核心区集中的现象,随着帽径比的增大,核心区对荷载分担的比例逐渐降低;随着帽径比的增大,单桩桩身轴力逐渐增大,但当帽径比K在2~6变化时,桩身轴力变化幅度不大;多桩复合地基中,随着帽径比的增大,桩身中性点逐渐下移,大约在桩顶下3~5倍桩径范围内变化;在荷载一定时,帽径比越大,单桩的沉降越大,桩土沉降差越小。因此,综合考虑以上因素,帽径比K的取值宜控制在2~4之间。
In order to study the influence of cap-diameter ratio on mechanical properties of rivetpile, combined with coastal highway reconstruction project, the influence law of cap diameter-ratio on pile top stress distribution, pile stress change and composite foundation settlement are studied by using ABAQUS finite element models. The results show that the stress distribution is not uniform in the range of pile cap but concentrated to the core area, the load sharing ratio gradually decreases when the cap diameter ratio increases; with the cap diameter ratio increasing, axial force of single pile increases gradually, but when the cap diameter ratio K is between 2~6, little changes occurred; in multi-piles composite foundation, the neutral point of pile shaft moves gradually down ward in the range of 3~5 times of the pile diameter; when the load is constant, the bigger the cap diameter-ratio is, the larger the settlement of the single pile is, but the smaller the differential settlement between pile and soil is. Therefore, considering all above factors, the cap diameter ratio to K should be controlled between 2~4.
In order to study the influence of cap-diameter ratio on mechanical properties of rivetpile, combined with coastal highway reconstruction project, the influence law of cap diameter-ratio on pile top stress distribution, pile stress change and composite foundation settlement are studied by using ABAQUS finite element models. The results show that the stress distribution is not uniform in the range of pile cap but concentrated to the core area, the load sharing ratio gradually decreases when the cap diameter ratio increases; with the cap diameter ratio increasing, axial force of single pile increases gradually, but when the cap diameter ratio K is between 2~6, little changes occurred; in multi-piles composite foundation, the neutral point of pile shaft moves gradually down ward in the range of 3~5 times of the pile diameter; when the load is constant, the bigger the cap diameter-ratio is, the larger the settlement of the single pile is, but the smaller the differential settlement between pile and soil is. Therefore, considering all above factors, the cap diameter ratio to K should be controlled between 2~4.
引文
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[7]周扬.变截面螺纹桩复合地基竖向承载特性研究[D].成都:西南交通大学,2015.
[8]谢胜华,刘松玉,杜广印.钉形粉喷桩加固海相软土地基的现场试验研究[J].西南交通大学学报,2012,47(2):204–209.
[9]徐剑.路基拓宽处理技术在沪宁高速公路中的应用研究[D].南京:东南大学,2005.
[10]谭儒蛟,张建根,徐鹏逍.带帽PTC桩在高速拓宽软土路基处理中的试验监测分析[J].工程勘察,2015,43(1):26–31.
[11]刘军,白永厚,李华寅.路堤荷载下桩帽式CFG桩对黄土地基的加固效果研究[J].路基工程,2015(5):144–148.
[12]郭帅杰.基于桩帽尺寸调整的桩网复合地基沉降控制方法研究[J].铁道标准设计,2016,60(11):5–9.
[13]雷金波.带帽控沉疏桩复合地基试验研究及作用机理分析[D].南京:河海大学,2005.
[14]曾俊铖.复合地基中桩帽作用数值分析及桩帽承载力计算[J].路基工程,2012(2):34–37.
[15]赵阳,陈昌富,王纯子.基于统一强度理论带帽刚性桩承载力上限分析[J].岩土力学,2016,37(6):1649–1656.
[16]陈昌富,米汪,赵湘龙.考虑高路堤土拱效应层状地基中带帽刚性桩复合地基的承载特性[J].中国公路学报,2016,29(7):1–9.
[17]王想勤,李建国.路堤荷载下刚性桩复合地基桩帽效应分析[J].成都大学学报(自然科学版),2013,32(3):298–302.
[18]吴燕泉.带桩帽刚性桩复合地基承载力设计计算方法研究[D].长沙:湖南大学,2013.