高压电缆排管变形控制标准破坏性试验研究

由于受周边建设活动的影响,高压电缆排管结构出现了沉降、变形和裂损等问题,但目前还没有针对这一电力系统独有的地下结构的保护控制指标和标准。基于地层-结构法开展了排管结构在外均布荷载作用下的破坏性试验和混凝土及保护管结构的受力和变形分析。结果表明,排管结构发生类似于少筋简支梁的“脆性破坏”,其极限承载力试验值远大于理论计算值,是因为理论计算没有考虑下卧土体地基反力和保护管加筋作用的贡献。建议将高压电缆排管结构内电缆保护管的变形作为长期监测指标,并重点关注其变化趋势;建议采用曲率半径来描述排管结构的纵向变形,并以最小曲率半径不小于18 000 m作为控制值。

Destructive Test Study on the Deformation Control Standard of Concrete Duct for High-voltage Cables

Under the impact of adjacent construction activities, settlement, deformation, cracking and damage of the concrete duct bank haven been occurred. However, no deformation control index and standards has been made for the concrete duct for high-voltage cables. Based on the soil-structure method, the destructive test of the concrete cable duct structure under external uniformly distributed loads was carried out. The stress and deformation of the concrete and internal pipes were analyzed. The results show a brittle failure of the concrete duct occurred, just as the failure of the rare-reinforced simply supported beam. The ultimate bearing capacity obtained in the experiment was much larger than its theoretical calculation, because the contribution of sub-soil and the reinforcement effect of internal pipe are not considered in theory. It is proposed that taking the deformation of internal pipe as the long-term monitoring index, and paying more attention to the trend change. The curvature radius is suggested to describe the longitudinal deformation of concrete duct bank. The limited value should not be less than 18 000 m as the control value.