“层叠”是中国历史城市的突出现象之一。徐州古称彭城，于1986年入选第二批国家历史文化名城，据地方志记载，因独特的地理位置，徐州城址基本未迁，呈现原址叠压状态。近代，徐州“城下城”的奇观因城市开发建设的展开而被重新发现，明清时期的城市格局仍依稀可辨，但由于种种原因，这一段城市历史被湮没于脚下，仅剩抽象的书面文字。
近年来，以地下商业和地铁2号线的开发建设为契机，徐州彭城广场地下商业规划中为遗址预留了一个面积较小的展览区域，以原址展现层叠的城市历史，同时也展示周边出土的重要文物。
▼项目概览，Preview © 秦伟
“Stacking” is one of the prominent phenomena in Chinese historical cities. Xuzhou, formerly known as Pengcheng, was selected as the second batch of Chinese National Famous Historical and Cultural Cities in 1986. According to local chronicles, due to its unique geographical location, the Xuzhou city site has not been relocated and presents a superimposed state of the original site. In modern times, the wonder of “City Under the City” in Xuzhou was rediscovered during the process of urban construction. The urban pattern of the Ming and Qing dynasties can still be vaguely discerned, but this period of urban history has been lost in abstract written texts due to various reasons.
In recent years, taking the development of underground commercial and subway line 2 as an opportunity, a small exhibition area has been reserved for the site in the underground commercial planning of Pengcheng Square in Xuzhou, presenting the superimposed urban history on the original site and displaying important unearthed cultural relics in the surrounding area.
▼历史地图与现代地图对位：城市结构及文脉节点分布（gif），Aligning Historical Maps with Modern Maps: Urban Structure and Nodal Distribution of Cultural Context © 中衡设计集团
1. 背景：市中心的城市遗址
Introduction：City Ruins in the City Centre
在徐州城市历史文脉保护的整体规划中，城下城博物馆是继城墙博物馆项目后、一个关键而特殊的城市节点。在横向的空间维度上，项目所在的彭城广场位于老城的市中心，具有重要的区位价值。城区主干道与地铁1、 2号线同时交汇于此，人流密集。在纵向的时间维度上，虽然上世纪以来彭城广场周边遗址发掘丰富，但原址保护的城下城遗址得到整体展示仍是首次。
2020年初，博物馆的设计工作提前于发现遗址的挖掘工作展开。方案以遗址的保护性开发为中心，随着地层的逐渐揭露，仅空间布局就进行了8次较大调整。在反复修改的过程中，项目团队始终坚持的设计出发点是如何处理建筑、遗址和城市的关系，从而再现层叠的城市历史。
In the overall planning for the protection of the historical context of Xuzhou city, the City under City Museum is a special urban node after the City Wall Museum project. In the horizontal spatial dimension, Pengcheng Square, where the project is, is located in the city center of the old district and has important location value. The main roads of the city intersect with subway lines 1 and 2 here, resulting in a dense flow of people. In the vertical time dimension, although the excavation of the surrounding sites of Pengcheng Square has been rich since the last century, the overall display of the in-situ protected urban ruins of the superimposed phenomenon is still the first time.
At the beginning of 2020, the design of the museum began before the excavation work of the site. The central focus of the plan was the protection of the ruins. With the gradual exposure of the strata, the spatial layout has undergone eight major adjustments. In the process of modifications, the design team has always insisted on the starting point of how to deal with the relationship between architecture, ruins and city, in order to represent the superimposed urban history.
▼原址保护与设计范围，In-situ conservation of the site and design scope © 中衡设计集团
2. 时空交错的体验之旅：博物馆与古今城市
Spatiotemporal Journeys：the Urban Square & heritage Museum
博物馆的展品是城市本身。毫无疑问，原址保护的古代城市遗址以及在附近挖掘出的单个文物是主要展品，但事实上，现代都市也是“叠城”中的重要展品。层叠的城市文脉由古今徐州共同组成。因而，博物馆并未采用常规的、螺旋上升或下降的线性路径来回应“城叠城”的历史过程，而是通过时空交错，为参观者营造出在古与今之间穿梭的空间错觉。
The exhibit of the museum is the city itself. While undoubtedly the primary exhibits are the ancient city ruins, the metropolis is also an important exhibit in the “stacked city” exhibition. The layered urban context is formed by the past and present of Xuzhou City. Therefore, instead of adopting a conventional linear path that spirals up or down to respond to the historical process of the superimposed city, the museum creates a spatial illusion of shuttle between the past and present through a journey of time and space.
▼城市入口，the main entrance of the museum © 秦伟
▼序厅，The Prelude Hall © 秦伟
其一，借助庭院的空间渗透作用，博物馆建立了地下城市遗址与周边都市环境的联系。位于中部的遗址大厅和考古大厅是博物馆的核心区域。遗址大厅主要展示挖掘出的明代文化层遗址，是古代徐州最繁荣的历史片段，正如明李东阳在《重修吕梁洪记》中写到，“东南漕运岁百余万艘，使船往来无虚日”。遗址大厅内，北门大街、铁匠铺、古井等遗址将明代徐州城的生活状态铺展于游人眼前。与之相对，在博物馆东端、平行于遗址大厅处插入了落瀑庭院。庭院通过瀑布的水声隐喻与河流紧密相关的城市历史，同时，将以苏宁广场为代表的现代徐州都市，随自然光线一起引入博物馆，与展厅中的明代城市遗址空间并置，链接徐州的过去与现在。
Firstly, through the spatial infiltration of the courtyard into inner space, the museum establishes a connection between the underground city ruins and the surrounding modern urban environment. The central ruin hall and archaeology hall are the core areas of the museum. The ruin hall mainly displays the excavation of the Ming Dynasty cultural layer ruins, which represents the most prosperous historical segment of ancient Xuzhou. As Li Dongyang(李东阳) wrote in “Revising the Record of Lu Liang Hong(吕梁洪),” “In the southeast, more than a million ships sailed on the Grand Canal every year, making their journeys without a single idle day.” In the ruin hall, the ruins of the North Gate Street, blacksmith shop, ancient well, and other sites show the life of the Ming Dynasty Xuzhou City. In contrast, a waterfall courtyard is inserted parallel to the ruin hall at the east end of the museum. The courtyard metaphorically relates the city’s history closely with the sound of waterfalls and rivers. At the same time, it introduces the modern Xuzhou city represented by tall buildings of Suning Plaza into the museum with natural light, juxtaposing the space of the Ming Dynasty city ruins in the exhibition hall and linking Xuzhou’s past and present.
▼遗址大厅，The heritage hall © 秦伟
▼从遗址大厅看考古大厅与落瀑庭院，The archaeological hall and the waterfall courtyard from the perspective of the site hall © 秦伟
▼落瀑庭院，The waterfall courtyard © 秦伟
▼庭院中的都市景象，Urban scenes through the courtyard © 秦伟
▼王宴德政碑，Wang Yan Dezheng Monument © 秦伟
其二，通过控制路径中的光线，以明暗对比加强博物馆的空间组织中古代城市遗址与现代都市环境的时空转换，从而调动参观者的身体知觉，沉浸感知“城叠城”奇观。如路径中标高最低的遗址断层墙展示厅，被有意地设计为光线最暗的节点，通过光线的减弱和高度的下降使参观者身历其境，以文化层断面直观地呈现城市遗址的层叠和历史的厚度。又如，博物馆最北端、面朝庭院打开的临时展厅，是空间序列中采光面积最大的节点，明亮的光线暗示出博物馆与城市广场的紧密关系。
Secondly, by controlling the light in the path and enhancing the temporal and spatial transformation of ancient city ruins and modern urban environments through contrast of light and darkness, the museum stimulates visitors’ bodily perception and immerses them in the spectacle of “city upon city.” For example, the ruin fault wall exhibition hall, which has the lowest elevation along the path, is intentionally designed to be the darkest point, immersing visitors in the thickness of history and the layers of the urban ruins through the reduction of light and the drop in height. Also, the temporary exhibition hall, which faces the courtyard at the northernmost end of the museum, is the node with the largest lighting area in the space sequence, and the bright light implies the close relationship between the museum and the urban square.
▼平面图：空间布局与流线设计，Floor plan: space layout and flow design © 中衡设计集团
▼空间体验与光线控制(gif)，Spatial experience and light control © 中衡设计集团
▼遗址断层墙展示厅（效果图/考古挖掘中），The site fault wall exhibition hall © 秦伟
▼草坡庭院与临时展厅，The grassy slope courtyard and temporary exhibition hall © 秦伟
3. 场地策略：博物馆与广场作为一个完整连续体
Site Strategies: Museum & Urban Square as a continuum
事实上，按照考古计划，未来整个彭城广场都将是遗址博物馆，目前先行完工的仅是一期部分，博物馆与遗址动态共存。其次，在展示和保护遗址之外，与城市广场、地下商业和地铁交通的紧密结合，是城下城博物馆的独特之处。因此，在博物馆与遗址、城市关系的处理上，设计始终需要将博物馆与场地作为一个完整连续体对待。
According to the archaeological plan, the entire Pengcheng Square(彭城广场) will become a site museum in the future, with only the first phase completed for now. The museum and the dynamic ruins coexist, and the unique feature of the museum is its close integration with the urban square, underground commercial areas, and subway transportation. Therefore, in the handling of the relationship between the museum, ruins, and the city, the project needs to treat the museum and the site as a complete continuum.
▼场地策略：博物馆与广场作为一个完整连续体（gif） ，Site Strategies: Museum & Urban Square as a continuum © 中衡设计集团
博物馆的场地策略可以用向两个方向“掀起”来概括：南侧拱形结构向外悬挑形成半开放空间，包裹城市主入口；北侧的拱形结构遮盖遗址为博物馆主体空间所在同时末端形成面朝广场的入口。借由这个动作，博物馆不仅掀开了广场，也掀起了“叠城”的层层历史。
The site strategy of the museum can be summarized by the action of “lifting” in two directions: the arched structure on the south side forms a semi-open space by projecting outwards, wrapping around the main entrance to the city. The arched structure on the north side covers the ruins as the main space of the museum while forming an entrance facing the square at the end. Through this action, the museum not only opens up the square but also lifts up the layers of history of the “stacked city.”
▼ 城下城博物馆南北向剖面图，North-south section © 中衡设计集团
▼城下城博物馆总平面图，Master Plan © 中衡设计集团
从广场北侧看博物馆，拱形结构略凸出地表，但在博物馆的正面仅留一条深色缝隙，暗示地下空间的存在。南侧拱形结构向外悬挑7米，将博物馆空间向城市延伸，形成半包围的主入口空间。
Looking at the museum from the north side of the square, the arched structure slightly protrudes from the ground, but only a dark gap is left on the front of the museum, suggesting the existence of the underground space. The arched structure on the south side projects outwards by 7 meters, extending the museum space to the city and forming a semi-enclosed main entrance space.
▼片墙控制视线，将人重新引向地面，The partition wall which controls the line of sight and leads people back to the modern urban landscape of Xuzhou © 秦伟
游人由东西两侧进入地下，片墙控制视线，将人重新引向地面，在打开湮没地下的城市记忆之前，回望现代徐州的都市景观。值得说明的是，在多方支持下，博物馆前原规划中的商业空间被置换为前院空间，院子以玻璃水池为顶，来自水池外现代都市的光线，透过水面散射在院子两侧的浮雕上，烘托出进入 “大红门”前的历史氛围。
Visitors enter the underground from both sides, and the partition wall controls the line of sight, leading people back to the modern urban landscape of Xuzhou before opening up the buried memories of the city. It is worth noting that with the support of multiple parties, the commercial space originally planned in front of the museum was replaced with a front courtyard space. The courtyard has a glass water pool as its top, and the light from the modern city outside the pool is scattered on the reliefs on both sides of the courtyard, creating a historical atmosphere before entering the “Great Red Gate”.
▼博物馆主入口“大红门”，The “Great Red Gate” © 秦伟
博物馆主体部分以先行挖掘的明代城市遗址为参观层基准高度。为保证参观层的层高，顶盖需抬起2m左右。为确保博物馆与广场融为一体，方案将顶盖设计缓坡形式。在北侧拱形结构与北侧彭城广场的交界处，地面下沉形成草坡庭院，作为博物馆与广场的柔性过渡，也增强了城市广场的空间连续性。同时，顶盖的铺装被设计为有肌理的渐变灰色，以向广场上活动的市民暗示地下展厅中北门大街遗址的存在，而作为博物馆的北入口，庭院中特意设置铺石路面遗址片段，指引游人通往古代徐州的路径。
The main part of the museum takes the excavated Ming Dynasty city ruins as the benchmark height for the visiting floor. To ensure the height of the visiting floor, the top cover needs to be raised by about 2 meters. To ensure that the museum is integrated with the square, the design of the top cover is a gentle slope. At the intersection of the arched structure on the north side and the Pengcheng Square on the north side, the ground sinks to form a grassy slope courtyard which services as a flexible transition between the museum and the square, enhancing the spatial continuity of the urban square. At the same time, the paving of the top cover is designed to be a gradually changing gray texture, suggesting the existence of the North Gate Street ruins in the underground exhibition hall to the citizens on the square. As the north entrance of the museum, a stone-paved road fragment is specially set in the courtyard to guide visitors to the path of ancient Xuzhou.
▼北侧广场入口：铺石路面遗址片段，The stone-paved road fragment in the grassy slope courtyard © 秦伟
“完整连续体”不仅体现在空间上，也体现在相应的技术处理上。其一，考虑地下考古工作的需要，博物馆顶盖选择了大跨度空间结构，采用密肋箱型框架结构形式，跨度达36m，并未采用常规的预制钢结构桁架，而是选择了现浇混凝土以结构表现力烘托历史的厚重感；其二，由于遗址大厅等遗址挖掘区保持遗址大厅底部与大地直接相连的状态，因而不能设计底面，项目主要采用止水桩打至不透水层形成止水结构来代替防水底面的做法，保证稳定性。
The “complete continuum” is not only reflected in the space but also in the corresponding technical treatment. Firstly, considering the need for underground archaeological work, the museum top cover chooses a large-span space structure and adopts a dense rib-box frame structure form with a span of 36m. It didn’t use the conventional prefabricated steel structure truss but has chosen cast-in-place concrete to express the historical sense of heaviness in structure. Secondly, since the ruins hall and other ruins excavation areas maintain a direct connection between the bottom of the ruins hall and the ground, there is no bottom surface. Therefore, the project mainly uses waterproof piles to be drilled into the impermeable layer to form a waterproof structure instead of a waterproof bottom surface to ensure stability.
▼城下城博物馆东西向剖面图，Section © 中衡设计集团
▼以结构表现力烘托历史的厚重感（考古大厅与遗址大厅），Express the historical sense of heaviness in structure © 秦伟
▼混凝土结构的光影效果，Light and shadow effects of concrete structures © 秦伟
在广场（顶盖）南部，一片台阶被有意增设于拱顶弧度最大处。正前方的玻璃水池加上下沉庭院中的落瀑声，以水暗示出古城与古黄河的紧密关系，为“叠城”遗址的成因留下了线索。人们坐在这里，透过广场的中轴线处的天窗，脚下的古城遗址隐约可见，而对面的都市景象是兴建中的高楼大厦。由此，博物馆不仅将城市广场的活动空间还给了市民，更重要的是启发一种对这座古城过去、现在与未来的思索。
In the southern part of the square (top cover), a set of stairs is intentionally added at the point where the arch is the highest. The glass water pool in front of the square, along with the sound of falling water in the sunken courtyard, suggests the close relationship between the ancient city and the ancient Yellow River, leaving clues to the origin of the “stacked city” site. Sitting here, people can vaguely see the ancient city site under their feet through the skylight on the central axis of the square, while the opposite urban landscape is a towering skyscraper under construction. As a result, the museum not only returns the activity space of the city square to the citizens but also inspires reflection on the past, present, and future of this ancient city.
▼顶盖南部台阶，A set of stairs In the southern part of the square © 秦伟
▼博物馆将广场空间还给城市，更重要的是启发一种反思，The museum not only returns the activity space of the city square to the citizens but also inspires reflection on this ancient city © 秦伟
4. 织补彭城：遗址、城市文脉与城市架构
Representation of Pengcheng：Ruins，Urban context & Urban structure
2010年至今，从古城墙边回龙窝历史地段中的城墙博物馆，到城市中心完整展示城市记忆的城下城博物馆，在徐州的一系列城市更新实践中，我们试图寻找散落于城市角落的历史遗脉，加以织补；关联历史轴线，恢复古城历史架构与界面；在更大的范围内，运用都市针灸的有机更新理念尝试将古城的文脉系统性地贯通起来，在这里，“针灸”并非局限于“节点”处理，而强调关键“穴位”的选择和整体结构系统的疏通。
In a series of urban renewal practices in Xuzhou since 2010, from the wall museum in the historical area of Huilongwo beside the ancient city wall to the city-under-the-city museum that displays the complete city memory in the city center, we have tried to find scattered historical traces in the corners of the city and patch them up; link historical axes, restore the historical structure and interface of the ancient city; on a larger scale, use the organic renewal concept of urban acupuncture to systematically connect the cultural context of the ancient city. Here, “acupuncture” is not limited to the treatment of “nodes” but emphasizes the selection of key “acupoints” and the unblocking of the overall structural system.
▼系列项目：徐州城市架构和历史记忆的保护，A series of urban renewal practices in Xuzhou since 2010 © 中衡设计集团
历史城市的保护与更新并不是一个“理想蓝图式”的规划。对于许多“旧貌换新颜”的城市来说，小心仔细地梳理历史文脉、不厌其烦地调整设计方案、由点到面地织补城市架构，或许才是古城更新的“捷径”。
In conclusion, the protection and renewal of historical cities are not a “blueprint” type of planning. For many cities that have undergone a “new look” transformation, carefully combing through historical contexts, tirelessly adjusting design schemes, and patching up the city’s structure from point to surface may be the “shortcut” for the revival of such ancient Chinese cities as Xuzhou.
▼城下城博物馆鸟瞰，The Aerial view © 秦伟
项目名称: 徐州城下城遗址博物馆
设计方: 中衡设计集团
项目设计 & 完成年份 2019-2022
主创建筑师: 冯正功 王旭
设计团队完整名单：
建筑: 冯正功，王志洪，王旭，鲁洁明，钱小玮，王嘉威
结构: 谈丽华，郭一峰，陆林浩
电气: 张渊，魏天蒙
暖通: 朱勇军，何光莹，高尚，赵云天，孙博涛
给排水: 陈绍军，薛学斌，唐毅涛
弱电: 王志翔，李业勤，王啸，钱奕男
幕墙: 沈筠，吕桂林，陆体操，刘树
景观: 张骏腾，俞德锋，陈戈岩，朱明燕，孟祥骏，王子瑞
内装: 张浩，马勤勤，曹献林
标识设计: 王登坤，魏国宏
项目地址: 江苏，徐州
建筑面积: 3735
摄影师：秦伟 版权：中衡设计
客户: 徐州地铁集团有限公司
品牌: 海尔多联式空调，海尔直膨式空调机组
|
