预应力管桩在广乐高速公路地基处理中的应用

发布时间：2018-05-06 16:50

本文选题：预应力混凝土管桩 + 稳定安全系数　；参考：《长安大学》2014年硕士论文

【摘要】：高速公路中利用预应力混凝土管桩处理地基设计的关键是预应力混凝土管桩竖向单桩承载力、路基稳定性及工后沉降的确定。本文在理论分析的基础之上，对广州-乐昌高速公路有代表性的路段按照其工程地质情况进行了路基稳定系数及工后沉降的计算。阐述了预应力混凝土管桩适于的地质条件、预应力混凝土管桩的分类及预应力混凝土管桩施工注意事项等。首先根据广州-乐昌高速公路软土路基病害特点，分析了桥梁方案的造价及水泥搅拌桩路基加固方案、塑料排水板路基加固方案、CFG桩路基加固方案、预应力混凝土桩路基加固方案的造价比较，确定了预应力混凝土管桩加固路基方案代替桥梁方案。建立了管桩加固高填土软土路基的计算模型，对高填土软土路基的沉降和稳定安全系数进行了计算；建立了刚性桩单桩承载力的计算模型，管桩处理下复核地基沉降和稳定安全系数计算模型，对路基安全性进行了计算分析。从后期的监控资料比较分析，该断面在路面铺筑前最大沉降16.6cm，计算理论值为57.6cm，，相差41.0cm，填土高度为14.0m，累计填土时间为14个月，累计侧向位移为3cm，且未出现失稳状态。从监测结果来看，利用预应力混凝土管桩加固软土地基时的沉降计算，当以刚性桩的计算模型来确定其的单桩承载力，与实际比较吻合。
[Abstract]:The determination of bearing capacity of vertical single pile, stability of roadbed and settlement after construction are the key points in the design of foundation treated by prestressed concrete pipe pile in expressway. On the basis of theoretical analysis, this paper calculates the subgrade stability coefficient and post-construction settlement of representative sections of Guangzhou-Lechang Expressway according to its engineering geological conditions. The geological conditions suitable for prestressed concrete pipe pile, the classification of prestressed concrete pipe pile and the matters needing attention in construction of prestressed concrete pipe pile are expounded. Firstly, according to the characteristics of soft soil roadbed disease of Guangzhou-Lechang Expressway, this paper analyzes the cost of bridge scheme, the reinforcement scheme of cement mixing pile subgrade, the reinforcement scheme of plastic drainage board subgrade and CFG pile roadbed reinforcement scheme. Compared with the cost of the reinforcement scheme of prestressed concrete pile subgrade, the scheme of strengthening roadbed with prestressed concrete pipe pile instead of bridge is determined. The calculation model of high fill soft soil roadbed is established, the settlement and stability safety factor of high fill soft soil subgrade are calculated, and the calculation model of single pile bearing capacity of rigid pile is established. The calculation model of foundation settlement and stability safety factor is checked under pipe pile treatment, and the safety of subgrade is calculated and analyzed. From the comparative analysis of monitoring data, the maximum settlement of this section is 16.6 cm before pavement paving, the calculated theoretical value is 57.6 cm, the difference is 41.0 cm, the fill height is 14.0 m, the cumulative filling time is 14 months, the cumulative lateral displacement is 3 cm, and there is no unstable state. From the monitoring results, the settlement calculation of soft soil foundation strengthened by prestressed concrete pipe pile is carried out. When the calculation model of rigid pile is used to determine the bearing capacity of single pile, it is in good agreement with the actual situation.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.1

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