埋深对大直径竹缠绕复合管涵受力性能影响实测与分析

Measurement and analysis of the effect of burial depth on the mechanical performance of large-diameter bamboo winding composite pipe

竹缠绕复合材料是我国竹材工业化应用领域的重要原创技术,突破了竹材传统应用的限制,在交通、市政、水利及建筑等多个领域具有广泛应用前景。为推广竹缠绕复合材料在公路工程中的应用,对大直径竹缠绕复合管涵实施现场监测并探究埋深对管涵力学性能的影响具有重要意义。设计了一套针对竹缠绕复合管涵的现场施工监测方法:实现从施工过程到服役期间的土压力、管底沉降、管壁应变全时段连续监测;对1~4 m埋深管涵的受力性能进行分析,探究了埋深对管涵受力性能的影响。试验结果表明:竹缠绕复合管涵属于柔性管涵,管土相互作用随埋深和时间的增加趋于明显,但在较浅埋深下受上部扰动较大;H1~H4最大竖向沉降为33.48 mm,所有管涵工后沉降均满足设计要求;由于管涵材料的变异性与初始缺陷,管顶竖向土压力变化幅度较大,且各埋深管涵管壁变形随时间变化不具有一致性规律;土压力、最大沉降值均随着埋深的增大而增大,除1 m埋深管涵外,随着埋深的增加,管上测点应变有增大趋势,管下测点应变有减小趋势,管涵有较好的适应性变形能力。

Bamboo winding composite pipe(BWCP) is a significant innovation in the industrial application of bamboo materials in China.It surpasses traditional bamboo applications and holds promising prospects in various fields including transportation,municipal,water conservancy and construction.To promote the application of bamboo composite materials in highway engineering,it is of great significance to implement on-site monitoring of large-diameter BWCP and investigate the influence of burial depth on the mechanical properties of BWCP.A set of on-site construction monitoring methods for BWCP is designed,which realizes the continuous monitoring of soil pressure,bottom settlement and wall stress from the construction process to the service period,and analyzes the stress performance of BWCP at a burial depth of 1-4 m to investigate the influence of burial depth on the stress performance of the pipe culvert.The test results showed that the BWCP belonged to flexible pipe culvert,and the pipe-soil interaction tended to be obvious with the increase of burial depth and time,but it was disturbed by the upper part in shallow burial depth;the maximum vertical settlement of H1-H4 was 33.48 mm,and all the pipe culverts satisfied the design requirements.Due to the variability of the BWCP material and initial defects,there was significant variation in the vertical earth pressure at the top of the tube.Additionally,the deformation of the wall of each pipe culvert varied inconsistently with the depth of burial.The earth pressure and the maximum settlement value increased with the increase of burial depth,except for the 1 m buried pipe culvert,with the increase of burial depth,the strain of the measuring point on the pipe had a tendency to increase,and the strain of the measuring point under the pipe had a tendency to decrease,and the pipe culvert had a good adaptive deformation ability.