基于熵权优化法的地下空间工程施工环境评价模型研究

Research on the construction environment evaluation model of underground space engineering based on entropy power optimization method

为全面地评价地下空间工程施工环境整体质量,建立了施工环境评价体系。常规环境子系统包括干球温度、相对湿度、照度、总粉尘质量浓度、呼吸性粉尘质量浓度、环境能见度、噪声、风速、氧气等。有毒有害气体子系统包括一氧化碳、氮氧化物、二氧化硫、瓦斯(甲烷)、硫化氢、氡气等。以重庆地铁18号线歇台子站为例,利用熵权优化的优劣解距离模型,对该站主体结构施工环境中进行现场监测的10个环境断面样本进行分析和评价。结果显示,呼吸性粉尘质量浓度、相对湿度、噪声和干球温度对整个施工环境有较大影响。最大权重为呼吸性粉尘质量浓度,权重为0.25;最小权重为风速,权重为0.08。施工区域左线及横通道处、主施工通道和区间通道交汇处施工环境较差。最优断面桩号为“ZDK12+704”,最差断面桩号为“ZDK12+679”。该模型可反映车站施工环境的各项监测指标信息,并可将单一环境要素评价扩展为整体综合的地下空间工程施工环境质量评价。

To comprehensively evaluate the overall quality of the construction environment of the underground space project,a construction environment evaluation system was established.Fifteen evaluation indicators were selected from the conventional environmental system and toxic and hazardous gas system.The conventional environment subsystem includes dry bulb temperature,relative humidity,illumination,total dust concentration,respiratory dust concentration,ambient visibility,noise,wind speed,oxygen,etc.The toxic and harmful gas subsystem includes carbon monoxide,nitrogen oxides,sulfur dioxide,gas(methane),hydrogen sulfide,Radon gas,etc.Taking Chongqing Metro Line 18 Xietaizi Station as an example,on-site monitoring of the construction environment of the main structure of the station was carried out.Ten environmental cross-section samples consisting of six monitoring indexes,namely dry bulb temperature,relative humidity,wind speed,noise,total dust concentration,and respiratory dust concentration,were selected from each monitoring result.The construction environment samples of the underground space project were analyzed and evaluated by using the distance model of superior and inferior solutions with entropy weight optimization.The results show that exhaled dust concentration,relative humidity,noise,and dry bulb temperature have a large impact on the overall construction environment.The maximum weight is the respiratory dust concentration with a weight value of 0.25.The minimum weight is the wind speed with a weight value of 0.08.The evaluation results of the construction environment of the main structure of the station are as follows:the overall construction environment is poor at the left line and the cross passage of the construction area,and the intersection of the main construction passage and the interval passage.The best section pile number is“ZDK12+704”.The worst section pile number is“ZDK12+679”.The evaluation results of the model can reflect the information of each monitoring index of the construction environment of the station.And it can extend the evaluation of a single environmental element into the overall comprehensive evaluation of the construction environment quality of underground space projects.The evaluation method is more integrated,comprehensive,and scientific.