Study On The Safety Of Green-roof Construction In High-density Residential City

Roof greening can increase the area of urban green space and improve the ecological environment.For cities with extremely high population densities,green roof construction is even more significant.According to interviews with experts,scholars and practitioners,due to the concerns of roof owners and managers about the safety of green roofs,there are still many suitable roofs that have not been built.Therefore,it is of great significance to establish a scientific roof greening safety assessment system,to conduct safety assessments of existing roof greening and suitable building roofs,to dispel people’s concerns,and to break through the bottleneck of roof greening development.This study takes the roof greening of Shanghai as an example,adopts expert scoring method,analytic hierarchy process(AHP)and fuzzy comprehensive evaluation method to construct a suitable roof greening safety evaluation system,and builds a scientific roof greening safety evaluation model.Based on the construction of the evaluation system,18 garden-style roof greenings were selected for safety research and evaluation.The result shows:(1)The safety evaluation scores of most roof greening are above 85,indicating that the safety of the roof greening plots surveyed in this survey is relatively good;but the roof greening with the highest evaluation value exceeds 90 points,and it has only just reached the ideal state;Five green roofs with a score lower than 85 points,and the evaluation value of the lowest green roof plot was only 79.32 points.(2)There are 2 Grade I roof greenings and 2Grade III roof greenings in the assessment level;the other 14 survey plots are all Grade II.(3)The scores of each factor layer in each survey plot are different,but the overall trend is consistent with the weight distribution predicted in the roof greening safety evaluation model.According to the above research results,taking the roof greening of Liangxiang Intelligent Engineering Co.,Ltd.as an example,to carry out research on roof green optimization design,and the relevant indicators in the evaluation system are used as the basis for safety design,and optimization measures are proposed for roof greening design schemes and construction.