先张自平衡预应力技术在桥面板构件中的应用

Application of pre-tensioned self-equilibrium prestressing technology in bridgedeck components

为解决传统桥面连续构造开裂、桥面径流渗漏的问题,采用先张自平衡预应力技术进行了桥面连续构造改造,通过预应力加载试验,研究了改造后桥面连续构造的受力性能。结果表明:在100 kN张拉力条件下,中空管的预应力损失约为16 MPa,预应力传递长度约为250 mm;桥面板构件实测储备纵向应力约为2.5~2.9 MPa;锚固区横向应力波形明显区域纵向长为350 mm,锚下劈裂应力峰值为1.20~1.30 MPa。工程实际应用表明:采用先张自平衡预应力技术的预应力桥面连续构造具有施工简便、适应性好、预应力施加可靠的特点,经过5年运营,未现可见病害,相比病害显著的传统方案具有显著的经济和社会效益。

In order to solve the problem of cracking on traditional bridge decks and the leakage of bridge deck runoff,the pre-tensioned self-equilibrium prestressing technology was adopted to improve the mechanical performance of the link slab of the bridge deck,and the prestressed loading test was carried out.The results show that under the tensile force of 100 kN,the loss of prestress in the middle air duct is about 16 MPa,the transfer length of prestress is about 250 mm,the measured reserve compressive stress of the bridge deck component is 2.5~2.9 MPa,and the longitudinal length of the anchorage zone with obvious transverse stress waveform is 350 mm,the peak splitting stress under the anchor is 1.20~1.30 MPa.The actual bridge engineering application shows that the link slab of bridge deck using pre-tensioned self-equilibrium technology has the characteristics of simple construction,good adaptability,and reliable pre-stressed application.After 5-year operation,no visible diseases have been observed,and compared to traditional schemes,it has significant economic and social benefits.