长江三角洲海岸剖面闭合深度的研究——Bruun法则及其应用的基本问题

本文对Ｂｒｕｕｎ法则应用的前提——海岸均衡剖面的基本问题进行了深入探讨，提出长江三角洲海岸不发育经典理论中砂质海岸那种较为严格的均衡剖面，但海岸剖面也有其较为稳定的特性，具有确定的闭合深度，这为在这种海岸上应用Ｂｒｕｕｎ法则提供了一定依据与可能。同时从动力、地貌与沉积综合研究出发，提出长江三角洲海岸存在的二种不同时间尺度闭合深度，在此基础上。

Permanent deformation response parameters of asphalt mixtures for a new mix-confined repeated load test

The main objective of this work is to propose new mixture response parameters and to compare correlations with rut depths and sensitivity of permanent deformation response parameters based on field extracted cores and lab-mixed duplicates. A new "mix-confined" test is developed and four new parameters for this test are proposed. Correlation coefficients with rut depths and coefficients of variation (sensitivity) are compared between the four new and two existing parameters. Some parameters are recommended to be used for the newly developed test. The results show that, newly developed test can capture the changes of permanent deformation of asphalt mixtures. Only one new parameter (D1 of Stephen Price model) and one existing parameter (flow number, Fn ) have strong correlations with rut depths of asphalt pavements (R2 greater than 0.7) and have relative small sensitivity (coefficient of variation, COV, less than 30%). For polymer modified asphalt mixtures, the parameter D1 rather than Fn should be used. These findings can be used to check the permanent deformation of asphalt mixture during the mix design.

钢桥裂纹气动冲击维修技术主要影响因素研究

针对钢桥疲劳裂纹气动冲击维修技术影响因素开展试验研究。考虑不同冲击头尺寸、冲击频率的影响,采用正交试验方法,对比分析了不同因素组合下冲击深度和裂纹开口闭合深度。通过对试验结果进行极差和方差分析,获得主要影响因素的显著性关系。采用有限元模拟了气动冲击维修过程,分析了不同因素下裂纹开口闭合深度及接触应力。研究结果表明：随着冲击头的增大,有效冲击深度减小,裂纹开口难以闭合。冲击频率是决定冲击深度的主要因素。随着冲击深度增加,裂纹开口闭合深度和接触应力均有一定增加,但增幅逐渐趋于平缓。有限元结果表明,当有效冲击深度为0. 25mm时,能够获得较好的实施效果。