干净简洁，错落有致——人行桥方案设计：造型，空间和结构

深圳·坪山中学跨河人行桥南沙原创建筑设计人行桥西侧鸟瞰___陈永裕设计原因该项目位于深圳东北部的坪山河干流，北岸是坪山中学和丰田世居（传统客家围屋），南岸为住宅与商业办公。在项目方圆1公里的步行距离内，没有联系南北两岸的桥梁。附近缺乏联系，不仅给学生接送带来不便，而且给锦龙大道或坪联路造成了交通拥挤，给城市生活带来不便。在对坪山的道路改善和交通环境进行征集活动，区政府决定在两条快速路之间修建一条过河的人行天桥，以方便教师，学生和居民在河南北两岸之间的通行，缓解该地区的高峰时段交通压力，为周边居民提供欣赏河景和休闲生活的场所。

深圳·坪山中学跨河人行桥

南沙原创建筑设计

人行桥西侧鸟瞰___陈永裕

设计原因

该项目位于深圳东北部的坪山河干流，北岸是坪山中学和丰田世居（传统客家围屋），南岸为住宅与商业办公。

在项目方圆1公里的步行距离内，没有联系南北两岸的桥梁。附近缺乏联系，不仅给学生接送带来不便，而且给锦龙大道或坪联路造成了交通拥挤，给城市生活带来不便。

在对坪山的道路改善和交通环境进行征集活动，区政府决定在两条快速路之间修建一条过河的人行天桥，以方便教师，学生和居民在河南北两岸之间的通行，缓解该地区的高峰时段交通压力，为周边居民提供欣赏河景和休闲生活的场所。

The Project spans over the main stream of Pingshan River in the northeast of Shenzhen, with Pingshan High School and Feng Tian Shi Ju (a traditional Hakka enclosed house) on the north bank and some residential, commercial and office buildings on the south bank. No bridge between the two banks was available within a 1-km walking distance of the Project. This lack of connection nearby caused not only inconvenience to student pick-up but also constant congestion, a nuisance to urban life, on the distant Jinlong Avenue to the west and Pinglian Road to the east of the Project. After a public survey on road improvement and traffic environment of Pingshan, the district government decided to build a river-crossing pedestrian bridge between the two expressways to enable convenient pedestrian circulation of teachers, students and residents between the north and south banks of the river, alleviate peak-time traffic pressure in the area, and provide a place for surrounding residents to enjoy the river view and a leisure life.

人行桥与周边环境__?张超

人行桥与滨水栈道

关于桥

桥梁作为一种特殊的建造类型，一直是一种特殊的存在。如果将交通连接视为其基本属性，那么空间性、地标性和文化的象征性也许是桥作为一个实体和空间存在的另一个重要的美学属性。

因此，如何在坪山特定场地创造一种新的视觉和交通体验，成为我们设计这座人行天桥的出发点和挑战。

Bridge, as a special building typology, has long been a special existence. If traffic connection is seen as its basic attribute, spatiality, landmark and cultural symbol may form other important attributes in terms of aesthetics for the existence of bridge, either as a physical entity or a space. Therefore, how to create a new visual and traffic experience at the specific site of Pingshan River became the starting point of and challenge for our design of this pedestrian bridge.

场地原始照片

坪山人行桥与日晖港步行桥

方案设计：造型，空间和结构

当接到设计邀请之初，对桥梁的位置并没有明确的界定，只提出桥梁的出入口不应直接面对学校的主入口和振环路的路口，也不能离太远。

根据学校主入口与振环路之间的关系，我们提出了四种空间位置的概选址方案和概念方案设计。

这些概念直接用简约风格清晰表达桥作为建筑空间、造型与结构三位一体的统一性。同时，还试图以传统客家文化的当代演绎作为设计的切入点，表达文化的传承理念。

When firstly approached by the client, no specific requirements were given on the location of the bridge, except that the bridge access should not directly face the main entrance of the school and the intersection of Zhenhuan Road nor stay too far away from them. Based on the relations between the main entrance of the school and Zhenhuan Road, we proposed four conceptual design options with different site locations. These proposals were expected to candidly showcase the consistency of architectural form and structure; meanwhile, they also attempted to interpret the traditional Hakka culture in a contemporary context, which served as the beginning point of the design.

四个概念方案_?南沙原创

人行桥空间位置提案

通过网络公投最终确定了实施的设计方案。具体来说，桥的中轴视线对振环路的开敞，偏离了学校的主入口。

为了避免放学后人群对道路路口的影响，该桥在南岸被一分为二，与人行道相连，形成Y形平面布局。这样，桥梁的建筑空间和结构形式便在设计中得以统一。

The design proposal for implementation was finalized through online public voting. Specifically, the central axis of the bridge, aligned with Zhenhuan Road, deviates from the main entrance of the school. To avoid the impact of after-school crowds on the road intersection, the bridge is split in two on the south bank to connect with the sidewalk, forming a Y-shape planar layout. This way, the architectural space and structural form of the bridge are unified in the design.

从振环路看向人行桥

这座桥横跨坪山河，全长70米。它的造型设计优先考虑桥和周围环境之间的关系。北岸桥出发点离校门前自行车道至少5米，尽量减少对校门交通流通的影响。

桥面主体结构应高于百年一遇的洪水位，并避开现状截污管井。满足无障碍通行且需转换南北两岸景观步道约1米的高差，桥底需保证作为滨水二级步道的舒适通行净高等。为了保护行人免受炎热和下雨的天气——典型的中国南方，桥上覆盖着线性屋顶，与不同高度的甲板形成对比，形成简洁、平静而坚固的桥梁。

The bridge spans 70 m over the Pingshan River. Its elevation design gives priority to the relation between the bridge deck and the surrounding environment. The starting point of the bridge on the north bank should be at least 5 m away from the cycling lane in front of the school gate to minimize the impact on traffic circulation at the school entrance. The main structure of the bridge deck should be higher than the once-in-a-century flood level and avoid the existing sewage interceptor well. While ensuring barrier-free access, the bridge deck should also be smoothly connected with the landscaped footpaths on the north and south banks that both show a height difference of about 1 m. The clear height below the bridge ensures comfortable pedestrian experience of the Grade II waterfront footpaths. To shelter pedestrians from the hot and rainy weather - typical of South China, the bridge is covered with a linear roof, which, in contrast with the varied height of the deck, contributes to a concise, calm yet solid presence of the bridge.

水平与转折

在满足上述要求和基本结构技术的条件下，合适的美学造型是首要的。因此，我们在桥的下部稍微弯曲，以消解地形标高和结构截面的差异性。对于桥的顶部，我们将其设置为一条水平线，以平衡下部以及桥面折转与差异所造成的失重。

这种简洁直接的形式传达出一种宁静的张力。为了平衡造型和美学，建筑师希望通过最直接的传力路径和最少的构件来展示建筑造型和结构的统一性。

A proper aesthetic shape is crucial to the bridge on the premise of meeting the above requirements and basic structural technology conditions. Therefore, we slightly bent over the lower part of the bridge to eliminate differences between terrain elevation and structural section. For the bridge top, we made it a horizontal line to balance the weight loss caused by the turn of and difference between the lower part and the deck of the bridge. This concise and straightforward form conveys a tension out of tranquility. To balance the form and aesthetics, architect intended to showcase the unity of form and structure via the most direct force transmission path and the least structural components .

折面钢板

起初，建筑师设想了一个类似于上海日辉港桥的结构系统，桥面用带有索的三叉张弦结构构成，桥顶采用悬垂钢板，钢板端部水平力由斜柱和拉索来抵抗。在第一轮结构配合中，考虑到大跨悬垂钢板屋面的抗风能力有限，而深圳夏季台风盛行，因此考虑适当增加立柱或抗风索来稳定桥顶。

在桥的顶部和底部增加连接构件后，整座桥的视觉感不可避免的向桁架靠近，这与三叉张弦梁的内在受力逻辑相冲突。结构工程师也希望避免重复日辉港桥的结构系统。因此提出了三向斜拉的结构方案。

At first, the architect conceived a structural system similar to that of Rihui Harbor Pedestrian Bridge in Shanghai. Specifically, the bridge deck appears as a cabled three-way string structure, while the bridge top is composed of suspended steel plates, the end horizontal force of which are resisted by inclined columns and cables. In the first round of structural coordination, it was planned to add some columns or wind resistant cables to stabilize the bridge top, given the limited resistance of long-span suspended steel plate roof to typhoons that prevail in summer in Shenzhen. After adding connection components between the top and bottom of the bridge, the entire bridge inevitably appeared similar to a truss structure, which conflicted with the inherent stress logic of the three-way beam string structure. Also the structural engineer wanted to avoid repeating the structural system of Rihui Harbor Pedestrian Bridge. That was how the three-way cable-stayed structure was provided instead.

结构方案的推演过程__和作结构

主桥桥面入口

在建筑师看来，斜拉桥的中部构件过于繁琐，视觉外观单一重复。起希望桥梁的空间和造型能够遵循结构的主次逻辑，桥顶尽可能的水平和轻盈，在跨中区域的两侧有开放的视野。

对此，也与结构师在结构设计的几个关键点上达成了一致，即避免采用桁架系统和三叉张弦梁，并探讨了桥顶与桥面在建筑与结构上统一编排的可能性。在此基础上，结构师发展了一种特殊的斜拉桥结构系统，将斜拉桥与三叉箱梁结合起来。

In the opinion of the architect, the middle-section components of the cable-stayed structure were too cumbersome and the visual appearance was monotonous and repetitive. The architect expected the space and form of the bridge could follow the primary and secondary logic of the structure, and the bridge-top be as horizontal and lightsome as possible, with open views on both sides of the mid-span area. In this regard, the architect and the structural engineer agreed on some key points of structural design, i.e. avoid both truss and three-way beam string systems, and explore the possibility to unified orchestration of the architecture and structure for the bridge top and deck. Eventually the discussions around those key points drew a conclusion that the cable-stayed pattern of the long side be retained, based on which the structural engineer developed a special structural system to combine the cable-stayed structure with three-way box girder.

分叉桥面入口

桥面斜拉杆之间和三叉交汇处的四个三角区采用板式斜拉，形成实面。然后将这种虚实关系延续到分叉桥面密集放置的细长柱上。这些列柱的数量、间距、角度可根据结构计算进行调整。

在实体模型上比较了几种方案后，我们最终选择了柱间距为1米，与桥顶之间呈75°。通过这样的设计方法，桥面在虚实之间实现了平衡；同时建筑与结构的关系也变得模糊，建筑的空间感和场所感被建筑分享。

With a consensus reached on the structural system, the architect redesigned the structure of the bridge by means of spatial composition. Steel plates are used to close up the four triangular areas between the diagonal rods of the main bridge deck at the three-way intersection, forming some solid surfaces. Such solidness-void relation is then extended to the densely placed slender columns at the bifurcated bridge deck. These columns are adjustable in quantity, interval and angle according to structural calculation. After comparing several options on mock-ups, we eventually selected the scheme featuring a column interval of 1 meter and an angle of 75° between the column and the bridge top. With such a design approach, the bridge facade achieves a well-proportioned balance between the solidness and void; meanwhile, the relation between architecture and structure becomes is blurred in a way that the former’s sense of space and place is shared by the latter.

人行桥分叉处

此外，在该系统中，桥面是弯曲受力(梁)和轴向受力(斜拉)系统的组合，而桥顶是纵向传力(箱梁)和横向传力(框架)传递的组合。体系在力流传递和视觉感知上不单一、直观，但内在传力逻辑清晰与明确。

这种虚实交错的解构体验是结构对空间和造型，是人为地传力路径多样化的结果。复杂性和多样性体现了在设计过程中力学和美学对多种需求的适应，而不是一味的追求复杂性。

What is worth mentioning is that, in this system, the bridge deck is a combination of bending force (beam) and axial force (cable-stayed) systems, while the bridge top is a combination of longitudinal (box girder) and transverse (frame) force transmissions. Although the system does not feature a single and straightforward way of force flow transmission and visual perception, it has a clear and articulated internal force transmission logic. Such deconstruction experience of staggered solidness and void is a structural response to space and form, and a result of artificially diversifying the force transmission path. The complexity and diversity reflect the adaptation of mechanics and aesthetics to multiple demands during the design process, instead of a blind pursuit of complexity.

结构系统分析图__和作结构

细节设计

在协调好整体空间造型与结构系统之间关系的同时，桥顶和桥面的变截面箱梁侧边用钢板收边，在视觉上削减结构的体量感，同时，不同折面的钢板在阳光照射下呈现出不同的光影效果，增加人行桥的立体感。

With a well-coordinated relation achieved between space and structure, the steel plates are used to close up the side edges of the variable cross-section box girders on the bridge top and deck, visually reducing the volume of the structure and bringing a lighter appearance to an otherwise heavy structure. The steel plates with different folded surfaces present varied light and shadow effect under the sunlight, enhancing the sense of space on the bridge .

玻璃栏杆与柱子

为了实现干净整洁的立面，栏杆采用了超白玻，而玻璃肋脚插入到桥面上的箱梁预留的U型槽内。分叉桥面玻璃栏杆的分缝方向和大小与斜柱对应。为了有效地排干桥面上过多的雨水，桥面与栏杆交接处使用角钢收边作为雨水的汇集槽，利用玻璃栏杆分缝之间的缝隙与桥面自然坡度进行排水。

To achieve a neat and clean facade, low-iron glass is employed for the railing, while the glass rib feet penetrate into the U-shape groove reserved for the box girder on the bridge deck. The joint direction and size of the glass railings on the bifurcated bridge decks are consistent with the inclined columns. To effectively drain the excessive rainfall on the bridge deck, angle steel close-up is used for storm water collection channel at the junction of the bridge deck and the railing, using the gaps between the glass railing joints and the natural slope of the bridge deck for drainage.

不同受力方式的过渡

中轴视线对振环路的开敞

在照明设计上，灯具和线管被隐藏在结构体量中，既提供节日模式，也提供日常模式，点光源和线性光源的结合，照亮了桥梁的结构构件。同时，水面上的倒影构成了另一道美丽的风景。

For lighting design, lamps and conduits are concealed in the structure volume, offering both festival mode and daily mode and combining point light source with linear ones to vividly illuminate the bridge’s structural components. The reflection of the bridge on the water surface makes for another beautiful view.

结语

综合上述，桥的立面和造型显得干净简洁，错落有致。最终的设计方案提供松紧有致、层次分明的视觉体验。建筑与结构之间的关系被变得模糊，以“表像逻辑”为基础的结构被赋予了空间和场所的意义。

With all these efforts, the bridge facade and form appear clean and concise with elegantly staggered solidness and void. The final design proposal features well-controlled tension and articulated hierarchy in visual experience. The boundary between architecture and structure is blurred, and the "representational logic"-based structure is bestowed with the meaning of space and place.