摘要
为减小粉砂土拼接路基与旧路基的差异沉降,采用碎石桩复合地基处治,建立了有限元模型,研究了碎石桩长度及其模量、桩间土模量及粘聚力对沉降及水平位移的影响.结果表明:桩长为5.0m时路基顶面最大沉降为9.8cm,最大差异沉降为5.3cm;碎石桩模量对沉降、坡脚水平位移及差异沉降的影响不显著;桩间土模量对路基沉降的影响较大,当桩间土的模量增大到14 MPa以后,路基的沉降趋于稳定,此时路基顶面沉降为7.15cm、最大差异沉降为3.87cm;桩间土粘聚力达10kPa后路基沉降趋于稳定,此时路基顶面沉降为9.8cm,最大差异沉降为5.2cm;新路基坡脚水平位移趋近于0.总之,碎石桩能明显减少沉降和侧向位移,碎石桩长5.0 m、桩间土模量14MPa、桩间土粘聚力10kPa时控制新路基沉降效果良好.
In order to reduce differential settlement between splicing subgrade and old subgrade, the treatment method of gravel pile composite foundation was employed. Based on the finite element model, in view of the length and modulus of gravel pile, modulus and cohesive foree of soil between piles, settlement and horizontal displacement were calculated, through which the influences factors and effects were analysed. The results show that the maximum settlement and differential settlement of subgrade surface are 9.8 cm and 5.3 cm, respectively, when the pile length is 5.0 m. The modulus of gravel pile has little influence on settlement, slope foot horizontal displacement and differential settlement of subgrade. However, the modulus of silty soil between piles has a large influence on settlement of subgrade. As soon as the modulus of the soil between piles meets 14 MPa, the settlement tends to be stable, when the settlement of subgrade surface is 7.15 cm, and the maximum differential settlement is 3.87 cm. Then, the subgrade settlement becomes stabilized when the cohesive force reaches 10 kPa, with a subgrade surface settlement of 9.8 cm and a maximum differential settlement of 5.2 cm. In the foregoing various conditions, the new subgrade slope toe horizontal displacement tends to zero. In a word, the gravel pile can significantly reduce the settlement and lateral displacement. To achieve the ideal effect, the length of gravel pile is 5.0 m, with a modulus 14 MPa and a cohesive force 10 kPa of silty soil between piles.
出处
《河南大学学报（自然科学版）》
CAS
2018年第1期98-106,共9页
Journal of Henan University:Natural Science
基金
河南省科技发展计划项目(162102210026)
河南大学省校区合作奖励补助资金项目(2016S12)
开封市科技发展计划项目(1602014)
关键词
道路工程
粉砂土
拼接路基
碎石桩
沉降控制
数值模拟
road engineering
silty soil
splicing subgrade
gravel pile
settlement control
numerical simulation
