基于典型病害的机场旧水泥混凝土道面沥青加铺结构研究

发布时间：2018-02-16 17:03

  本文关键词： 机场 沥青加铺层 行驶状态 轮辙 静力响应 动力响应 差异设计　出处：《长安大学》2016年硕士论文　论文类型：学位论文

【摘要】：我国在80~90年代修建的水泥混凝土机场跑道陆续进入使用后期,迫切需要在不停航施工条件下进行结构补强或功能恢复,从而使得满足不停航要求的白改黑沥青加铺技术成为一种常用改造措施。但是,由于飞机在平行滑行道、联络道及跑道上行驶状态的极大差异,导致飞行区局部区域在使用两三年后即出现严重早期病害,尤其在重载、高温等不利耦合条件下,平行滑行道及联络道轮辙病害迅速产生及发展。因此,系统研究飞行区上述区域抗轮辙技术并建立一套适用于此种行驶状态的设计方法应用前景广阔。本文首先通过对国内几个机场飞行区典型病害调查,发现失稳型轮辙、抗剪切强度不足产生的推移是机场沥青加铺结构主要病害类型,主要集中在平行滑行道、联络道及跑道端部;通过对加铺结构变形机理阐述,说明常用SMA+AC组合形式抗变形能力满足跑道中部要求,但由于飞机荷载作用时间及方式的显著差异并不适用于上述病害集中区域。其次,通过有限元软件,基于停滞、低速及高速(0m/s、5m/s、50m/s)三种行驶状态,分别分析了荷载、温度、模量及应力吸收层厚度及模量变化下沥青加铺结构静力及动力响应。结果表明,加铺层在大型飞机荷载及高温下将处于不利受力状态,荷载增大1倍后,其剪应力、剪应变均增大1倍;温度从20℃增大到50℃后,剪应力减小10%剪应变则增大168%。然而,下面层模量从1500MPa增加到3600MPa后,剪应力虽增加了29.2%,但剪应变降低了43.1%,且降幅逐渐降低,以此推荐出合理模量范围为2100~2700MPa。随应力吸收层厚度(模量)增长,层底剪应力先明显降低后缓慢增长(逐渐增大),层内最大剪应力则逐渐增大(逐渐减小),综合考虑其厚度为1~2cm、模量为300MPa左右或采用APP油毡防裂措施较为合理;不同行驶速度下,其剪应力、剪应变及路表弯沉随速度的增大呈“S”型减小趋势,50m/s下其剪应力、剪应变及弯沉分别较5m/s下降低5.9%、3.9%及38.1%,说明速度主要影响弯沉,其次是应力应变。然后,基于粘弹性理论建立轮辙数值计算模型,分析行驶速度、荷载、温度对沥青加铺层轮辙的影响,得出5m/s下轮辙为50m/s下的2.63倍、荷载增大1倍后轮辙增大49%、50℃下轮辙为40℃下的2.82倍,在重载、低速、高温条件下将处于极限不利受力状态;同时对不同材料类型及厚度组合下平行滑行道、联络道及跑道的永久变形进行分析,推荐适合于不同行驶状态的结构组合形式及厚度。最后,结合本文分析及现有规范,提出以容许剪应力及容许轮辙为验算指标的飞行区不同区域沥青加铺结构差异化设计方法。
[Abstract]:The cement concrete airport runway built in the 1980s and 1990s in our country has entered the later stage of operation, so it is urgent to strengthen the structure or restore the function without stopping the construction. Thus, the white to black asphalt overlay technology, which meets the requirements of non-stop operation, has become a common retrofit measure. However, due to the great differences in the running state of the aircraft in parallel taxiways, liaison roads and runways, As a result, serious early diseases occur in the local area of the flying area after two or three years of service, especially under unfavorable coupling conditions such as heavy load, high temperature, etc., the parallel taxiway and junction track rutting diseases occur and develop rapidly. This paper systematically studies the anti-rutting technology of the above mentioned areas in the flying area and establishes a design method suitable for this kind of driving state, which has a bright future. Firstly, through the investigation of typical diseases in several domestic airports, the unstable rutting is found. The passage of insufficient shear strength is the main disease type of airport asphalt overlay structure, mainly concentrated in parallel taxiway, junction road and end of runway. It shows that the common SMA AC combination can meet the requirements of the middle part of the runway, but the significant difference in the time and mode of aircraft loading is not suitable for the above disease concentration area. Secondly, through the finite element software, based on stagnation, The static and dynamic responses of asphalt overlay structure under load, temperature, modulus and stress absorption layer thickness and modulus are analyzed in three driving states: low speed and high speed 0 m / s / s 5 m / s / s. The results show that, The overlay will be in a disadvantageous state under the load of large aircraft and at high temperature. When the load increases by 1 times, the shear stress and strain of the overlay will increase by 1 times, and the shear stress will decrease by 10% when the temperature increases from 20 鈩，

本文编号：1516008