浅析城市沥青路面压实影响

影响沥青路面压实效果的因素很多，包括沥青混合料及集（填）料、沥青等原材料的性能指标，施工温度，压路机类型和质量、速度、遍数，压实施工组织措施等，应从设计、材料和施工等环节做好分析、预防和控制。对于路面未达有效压实成型时间即开放交通，以及超载车辆等难点，有待进一步研究与探讨。

基于PQI快速检测的沥青路面压实影响研究

应用PQI技术,依托实体工程,研究了碾压温度和碾压速度对沥青路面压实效果的影响。结果表明:(1)PQI路面密度快速测试方法应用可靠性较高;(2)采用PQI测试压实路面密度变化,可快速确定合理的碾压温度范围;(3)碾压速度过快会造成路面密度和压实度降低。施工时,碾压速度不宜照搬规范,建议采用PQI快速检测压实效果,确定合理的初压和复压速度。

浅谈如何控制路基压实度的质量

针对公路路基工程质量的重要性,研究了公路路基压实度的影响因素,从而确保路基压实达到设计要求,同时为以后的路基压实施工提供了参考。

浅谈“人工压实”对提高道路场地工程总体质量的意义

化工企业总图运输设计中“人工压实”对提高道路场地工程总体质量的意义,人工压实的重要意义,人工压实对路基路面材料强度的增加、减少路基土和路面材料塑性形变、增加材料稳定性;影响人工压实的因素,材料含水量、压实厚度、压实机械选择等.

沥青混凝土路面碾压技术

介绍了沥青混凝土压实度的重要意义、影响压实效果的因素、碾压程序、纵横向接缝的碾压、施工现场的质量管理及检验的主要内容,旨在提高沥青混凝土路面的施工质量。

An Experimental Study on the Wave-Induced Pore Water Pressure Change and Relative Influencing Factors in the Silty Seabed

In this study, a flume experiment was designed to investigate the characteristics of wave-induced pore water pressure in the soil of a silty seabed with different clay contents, soil layer buried depths and wave heights respectively. The study showed that water waves propagating over silty seabed can induce significant change of pore water pressure, and the amplitude of pore pressure depends on depth of buried soil layer, clay content and wave height, which are considered as the three influencing factors for pore water pressure change. The pressure will attenuate according to exponential law with increase of soil layer buried depth, and the attenuation being more rapid in those soil layers with higher clay content and greater wave height. The pore pressure in silty seabed increases rapidly in the initial stage of wave action, then decreases gradually to a stable value, depending on the depth of buried soil layer, clay content and wave height. The peak value of pore pressure will increase if clay content or depth of buried soil layer decreases, or wave height increases. The analysis indicated that these soils with 5% clay content and waves with higher wave height produce instability in bed easier, and that the wave energy is mostly dissipated near the surface of soils and 5% clay content in soils can prevent pore pressure from dissipating immediately.

Experimental Investigation of Effects of Suction-Side Squealer Tip Geometry on the Flow Field in a Large-scale Axial Compressor using SPIV

It is well known that the non-uniform tip geometry is a promising passive flow control technique in turbomachinery.However,detailed investigation of its effects on the unsteady flow field of turbomachinery is rare in the existiug hteratures.This paper presents an experimental investigation of effects of suction side squealer tip configuration on both the steady and unsteady flow field of an isolated compressor rotor.The flow field at 10%chord downstream from the trailing edge was measured using a mini five-hole probe.Meanwhile,the unsteady flow field inside the passage was investigated using stereo particle image velocimetry(SPIV).The steady results show that the SSQ tip configuration exerts positive effect on the static pressure rise performance of this compressor,and the radial equilibrium at the rotor outlet is obviously rearranged.The SSQ tip configuration would create a stronger tip leakage vortex at the formation phase,and it experiences a faster dissipation process around the rear chord.Also,the splitting process of the tip leakage vortex is severer,which is the main cause of the relatively higher probability of the presence of the streamwise reverse flow.The quantitatively analysis of the tip leakage vortex indicates that the velocity loss inside the blockage region is direct response of the evolutionary procedure of the tip leakage vortex.It keeps increasing until the end of the splitting process.Although the blockage coefficient grows sustainably,the velocity loss will reduce once the turbulent mixing procedure is dominant.

Experimental Investigation of Boiling Two-phase Flow Instability of Nitrogen in a Vertical Tube

Boiling flow instability of nitrogen in a vertical tube is experimentally investigated in the present study. The experiments reveal that pressure has a significant effect on the characteristics of the heat flux-mass flux type boiling flow instability.First.the pressure has strong effects on both the developing time and the fluctuation amplitude.Especially increasing pressure leads to decrease the fluctuating amplitude of mass flux.Then,the mass flux evolving curves under different pressures feature out a shape like a leaf.The characteristics of the heat flux-mass flux type boiling flow instability under lower pressure are very complicated,however,with increasing pressure,this type of instability is gradually suppressed.