单管旋喷工法成桩半径实用计算方法

发布时间：2018-05-31 16:32

本文选题：道路工程 + 软土地基　；参考：《长安大学学报(自然科学版)》2017年04期

【摘要】：为解决在采用单管旋喷工法对软土地基加固时,对成桩半径的合理预测问题,通过对单管旋喷工法施工过程的理论分析,以单位长度高压旋喷桩为研究对象,综合考虑水泥浆射流性质、高压射流喷射能量和土体抵抗力,提出一种预测单管旋喷桩成桩半径的实用计算方法。该方法针对细粒土和粗粒土情况,选取岩土工程勘察报告中常用的静力触探试验获得的锥尖阻力q_c和标准贯入试验获得的标贯击数N_(SPT)代表土体抵抗力;建立成桩半径与喷嘴处高压射流喷射能量E_n和土体抵抗力(锥尖阻力q_c和标贯击数N_(SPT))的定量关系;同时分析成桩半径随高压射流喷射能量E_n、锥尖阻力q_c和标贯击数N_(SPT)的变化情况;最后总结了该方法的计算步骤,并通过与现场实测数据的对比分析,验证了该方法的合理性。研究结果表明:成桩半径随锥尖阻力q_c(细粒土)和标贯击数N_(SPT)(粗粒土)的增大迅速减小,即土体抵抗冲刷破坏的能力越强,成桩半径越小;喷嘴处高压射流喷射能量E_n越大,代表高压射流对土体的破坏力越强,则成桩半径越大;在喷射参数相同的情况下,单管旋喷工法在粗粒土中的成桩半径一般要高于细粒土中的成桩半径。
[Abstract]:In order to solve the problem of reasonable prediction of pile radius when the soft soil foundation is strengthened by single pipe rotary grouting method, through the theoretical analysis of the construction process of single pipe rotary jet grouting method, the unit length high pressure rotary jet grouting pile is taken as the research object. Considering the properties of cement slurry jet high pressure jet injection energy and soil resistance a practical calculation method for predicting the pile radius of single pipe rotating jet pile is presented. According to the condition of fine grained soil and coarse grained soil, the cone tip resistance obtained from static penetration test and standard penetration test, which is commonly used in geotechnical engineering investigation report, is selected to represent soil resistance. The quantitative relationship between pile radius and jet energy E _ n at the nozzle and soil resistance (cone tip resistance Q _ C and standard penetration number N _ T _ T _ n) was established. At the same time, the variation of pile radius with high pressure jet injection energy E n, cone tip resistance Q C and standard penetration stroke number N D SPT is analyzed, and the calculation steps of the method are summarized, and the rationality of the method is verified by comparing with the field measured data. The results show that the pile radius decreases rapidly with the increase of taper tip resistance Q _ c (fine grained soil) and standard penetration number N _ S _ T _ T _ T (coarse grained soil), that is, the stronger the ability of soil to resist erosion damage, the smaller the pile radius, and the greater the jet energy E _ n at the nozzle. The results show that the more destructive force of high pressure jet on soil, the bigger the pile radius, and the bigger the pile radius of single pipe rotating injection method in coarse grained soil is, the higher the pile radius is in fine grained soil.
【作者单位】：长安大学公路学院;长安大学陕西省公路桥梁与隧道重点实验室;温州市交通工程质量监督局;温州信达交通工程试验检测有限公司;
【基金】：中国博士后科学基金项目(2015M570803,2016T90877) 陕西省博士后科研项目中央高校基本科研业务费专项资金项目(310821161022)
【分类号】：U416.1

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