【作者】 李焕龙；

【导师】 楼文娟；

【作者基本信息】 浙江大学 ， 结构工程， 2010， 博士

【摘要】 墙体水密性问题将引起建筑安全、节能等方面的一系列问题,还可能导致不健康的室内生活环境。伴随着围护墙的轻质化改革,轻质围护墙的雨水渗漏问题有所凸显。等压雨幕墙正是在这一背景下诞生的。等压雨幕墙在雨水防渗方面的表现相比单层墙、排水夹空墙或简单雨幕墙更为可靠。该类雨幕墙在内层墙作气密性要求及外层墙上人为设置开口的同时将墙体空腔分隔成数个独立单元,使其外层墙两侧实现最大程度的压力平衡。针对压强传递频域解法及其精度、参数变化影响规律、风压空间相关性的影响情况、风洞实验缩尺建模的相似准则等4个等压雨幕墙压力平衡研究中存在的问题和不足,本文开展了如下研究：一、借助线性化推导了气屏柔性无渗漏等压雨幕墙压强传递的频域解法；并参照常规工况建立典型算例对气屏刚性无渗漏、气屏刚性有渗漏、气屏柔性无渗漏等三种等压雨幕墙压强传递频域解法的精度进行了检验。研究发现,频域解法对三种等压雨幕墙常规情况下的压强传递求解是适用的,其精度是满足工程要求的。二、在对频域解法所得的压差传递函数进行符号求导的基础上,结合算例校验工作,以一种半理论半经验的方式对风压作用下相关参数对三种等压雨幕墙压力平衡的影响规律进行了分析。相关研究成果可以更有力地指导雨幕墙的防渗设计。三、研究了风压空间相关性对等压雨幕墙压力平衡的影响。对雨幕孔口压差、雨幕两侧空间平均压差、雨幕上局部点位的压差以及空腔隔板压差等四种压差推导了可同时考虑系统动力特性和风压相关性影响的连续型计算模型；并基于连续型计算模型发展了离散型计算模型及其简化算法以提高计算效率。同时,还给出了压强传递准静态假定下的计算模型。另外,通过算例,考查了上述四种压差离散模型简化算法的精度及压强传递准静态假定下计算结果的有效性,分析了四种压差的形成机理和变化规律。四、基于相关控制方程研究了等压雨幕墙风洞试验缩尺建模的相似准则。分析了亥姆霍兹共振器模型在等压雨幕墙压力平衡研究中的适用性；并通过引入特征长度和特征速度将基于亥姆霍兹共振器模型的控制方程组实现了无量纲化,进而获得了相似准数,并由相似准数确定了相关物理量的相似常数。此外,还讨论了雨幕墙压强传递系统的相似准则在实际风洞试验中的满足情况。并且,通过求解控制方程考查了风洞试验中舍弃某些次要相似准则对试验结果有效性的影响。更多还原

【Abstract】 Water leakage of a wall may cause a building’s structure failure and loss of energy efficiency, and may also lead to unhealthy indoor living environment. With the walls’weight lightening reform, the rain leakage problem begins to be bothersome for the light-weighted walls. The pressure equalized rain-screen (PER) walls were exactly proposed in this context. The PER walls’ water-tightness performance is more reliable, compared to the single-line barrier walls, the drained cavity walls, and the simple rain-screen walls. Based on the inner layer’s air tightness and the outer layer’s intentional openings, a PER wall’s cavity will be divided into several compartments to achieve a more percentage of pressure equalization across its outer layer.Considing the problems and shortages on the study of the PER walls’pressure equalization, such as:the frequency-domain solution of the pressure transfer and its precision, the law of the parameters’ influence, the impact of the wind pressure’s spatial correlation, the scaling similarity criterion of modeling in the wind tunnel test, this study carried out as follows:Firstly, the frequency-domain solution of pressure transfer for the PER walls with flexible non-leaky air barrier was deduced based on linearation. And the accuracy of the frequency-domain solutions for the PER walls above-mentioned and the PER walls respectively with rigid leaky air barrier or rigid non-leaky air barrier was tested at conventional conditions by solving typical examples. Case calculations verified that the frequency-domain solution of pressure transfer for those three kinds of the PER walls is applicable, and the precision of those solutions meets the project requirements well.Secondly, to understand the law of the parameters’ influence on the PER walls’pressure equalization under wind excitation more in-depth and comprehensively, analysis was carried out in a semi-theoretical semi-empirical way based on the symbolic derivative of the pressure transfer function of the frequency-domain solution and combined with some nesessiry checking by case calculations. Base on that, the PER walls’ water-tight design can be guided more effectively.Thirdly, in order to simulate the influence of the wind pressure’s spatial correlation on the PER walls’pressure equalization more truly, continuous calculation models for four kinds of pressure drop, such as:the pressure drop at the opening, the space average pressure drop across the rain-screen, the pressure drop at some point on the rain-screen, and the pressure drop across compartment seal, were deduced. Meanwhile, discrete calculation models and their simplied algorithms were derived based on continuous calculation models to achieve fast algorithms. Those models can simultaneously consider the dynamic characteristics of the PER walls and the wind correlation. Besides that, the calculation models under the quasi-static approximation of the PER walls’ pressure transfer were also deduced. Moreover, by case calculations, the accuracy of the simplied algorithms and the effectiveness of the models under the quasi-static approximation of the pressure transfer were examined; the formation mechanism and the change law of those four pressure drops were analyzed.Fourthly, based on some related control equations, the scaling similarity criterion for the PER walls’ modeling in the wind tunnel tests was derived. The applicability of the Helmholtz resonator model in the study of the PER walls’ pressure equalization was analyzed. And the control equations for the pressure transfer were normalized by introducing a characteristic length and a characteristic velocity. Then the similarity parameters were obtained, and the similarity factors of relevant parameters were determined. Besides that, the realizability of the similarity criterion for the PER walls’ modeling in actual wind tunnel tests was investigated. And the impact of some modeling error to the test results was inspected by numerical solution based on control equations.更多还原