Research On The Optimization Of Connected Underground Space In The Context Of Famous City Protection

With the continuous social and economic development,the urban traffic volume is gradually rising,the layout of the ancient city area and the current road network has been difficult to meet the requirements of urban motorized development,the protection of the ancient city and the coordinated development of traffic has become a very important aspect in the process of urbanization,at the same time,the development and utilization of Underground Space(US)is becoming a new focus of urban construction.Therefore,to seek the balance between historical and cultural Protection and urban transportation development,carry out optimization research on existing point-US contiguity network under the background of Famous City Protection(FCP),and build regional underground transportation network.It is very necessary to alleviate the traffic jam,divert the dense crowd,reduce the pressure of ground traffic and promote the sustainable development of the ancient city.In this paper,the concept of FCP and the existing point US is defined.According to the layout mode of the existing point US connected network construction,and the demand of suzhou ancient city US connected network,the construction strategy of US motor vehicle network is determined as the connected network construction strategy.The preliminary underground connection network is set as the initial value.Through the comparison of optimization methods,the accessibility-oriented continuous network optimization framework is determined From FCP constraints,underground connectivity,existing point US,transportation system,travelers on the specific impact of the optimization of FCP network optimization index system.In this paper,the model is constructed according to the optimization framework and index system of continuous networking,and the optimal result is obtained by repeated iterative operation of the two-layer model,and the optimization and construction strategy that may be adopted by the initial underground connection network is selected.Among them,the upper layer model considers the constraints of the total investment in the construction of contiguous networking,the scale of the underground road network,and the service level of underground roads,defines FCP-US accessibility according to the purpose of contiguous networking,takes FCP-US accessibility as the goal,takes the spatial interaction model as the modeling basis,establishes the existing US node importance model as the attraction strength,and establishes the FCP-US connectivity difficulty model and the personal travel impedance function combined into a generalized comprehensive impedance.Based on the specific indicators of continuous network optimization,an FCPUS accessibility model is constructed.The lower layer adopts the combined model of traffic distribution and balanced distribution that considers the individual travel impedance,distributes traffic flow,establishes an FCP-US contiguous networked double-layer model based on accessibility,designs a genetic algorithm for the model,and a Frank-Wolfe algorithm for the model,and gives the model solution process.Finally using guanqian street in suzhou city as the model,the empirical application of guanqian street area both point US coalesced into network optimization research,the weight coefficient of the model and the control parameters of the calibration and verification in this paper,the proposed based on the accessibility of FCP-US shall into the effectiveness of the network optimization model,get the guanqian street both point US to shape into a network optimization layout scheme.