二分桥 Project Name:Split Bridge

深圳是全球建设速度最快的大都市，以每年超过一千公顷的新增建设用地实现扩张。小梅沙位于深圳东部大鹏湾，三面环山，一面临水，素来是深圳人亲近自然的休闲去处。二分桥便是为前来游玩的行人过湖而设。该设计把紧张的都市人引入慢的意境之中，放松和亲近自然。

Shenzhen is the fastest-growing city in the world, expanding over 1000 hectares of new construction land each year. Xiaomeisha is located in Dapeng Bay in the east part of the city, surrounded by mountains on three sides and facing the water on one side. It has always been a valuable natural spot for people to escape from urban chaos. Here the Split Bridge is designed for hikers to cross the lake. The idea of splitting the footbridge in to two paths is to open up choices of calm and relax for urbanites.

▼二分桥，Split Bridge ©白羽

步行桥共计八米宽，一分为二。取四米笔直桥身一跃而过，为过桥的人们提供平坦和便捷，是步行、慢跑、骑行、轮椅、小童车都能使用的无障碍通道。取四米桥身起伏，往下贴到湖面，往上高于马路，这是一条休闲步道，流线的设计让人能够慢下来，或者说，让人有了慢下来的选择。

The eight-meters-wide bridge is splatted into two four-meters passages. One is a straight body, which provides flatness. This is a barrier-free passage that can be used by walking, jogging, cycling, wheelchairs, and small strollers. The other one is an undulating leisure trail, which runs from ground level down to lake water level and up to higher level that overlooks the driveway. The streamlined design allows people to slow down, or in other words, gives people a choice to slow down, if they wish to.

▼八米宽的桥面一分为二，the eight-meters-wide bridge is splatted into two four-meters passages ©白羽

▼一边是笔直平坦的无障碍通道，一边是起伏的休闲步道 ©白羽 one of the two passages is a straight body, while the other one is an undulating leisure trail

一道桥要成为一道风景，中国古典园林中的玉带桥便是很好的诠释。平静的湖面是直，起伏的山丘是曲，二分桥的曲直交错与之相映成趣，同时也为游人制造了不同的视点。

To become a landscape feature, the design looks in to Jade Belt Bridge (famous in Chinese classical gardens) as reference. Straight line reflects water surface, while curved line represents the undulating hills. Two passage of Split Bridge makes a combination of both. Also, the different heights of walking trails create interesting viewpoints for spectators.

▼二分桥的曲直交错与平静的湖面相映成趣，straight line reflects water surface, while curved line represents the undulating hills ©白羽

桥身的平面主要是由一段直线和一段相切弧线构成，而桥身立面则主要是由多段直线和多段相切弧线构成。为了满足施工上的易实施性，设计师反复优化桥身几何构成，调整平面和立面的曲线分布，让平面直线段对应立面曲线段、平面曲线段对应立面直线段，以避免空间的双曲面而增加施工难度。

▼平面图，plan ©Jane Z Studio

We want simple solutions in construction. In plan, the bridge body is mainly composed of one straight line and one tangent arc, while the elevation is composed of multiple straight lines and multiple tangent arcs. To meet simple implementation during construction period, the design optimized the geometric composition and adjusted the curve distribution to have correspondence between the straight lines of the plane and the curve segment of the elevation, and vice versa, avoiding hyperboloid geometry.

▼从林间望向二分桥，view from the trees ©白羽

为了平衡梁高与柱跨之间的关系，以及释放桥梁收缩、徐变及温度应力，设计师对桥梁进行了合理的结构分缝来调整桥身柱位。为了将梁高控制在750mm以内，因此柱跨按15~22m进行取值。桥梁分缝为三段，分缝处采用两侧挑梁的方式，挑梁长度则控制在4m以内。

To weigh the height and span of beams, also to release the bridge shrinkage, creep, and temperature stress, the design used rational structural division to compromise column position. In order to keep beam size within 750mm high, the column span was kept between 15 to 22 meters. The bridge body was divided into three parts. The juncture was formed by cantilever beams on both sides. The length of cantilever beams is within 4m.

▼立面图，elevation ©Jane Z Studio

作为一个便民的市政项目，二分桥的设计主张节约的原则，兼具快速建造的可能性。同时，考虑到降低后期的维护，设计师采用较为基础的建筑材料，如彩色沥青桥面，地砖，金属栏杆等。此外，由于海边腐蚀性严重，为了保证结构的耐久性，桥身主体采用现浇钢筋混凝土结构，结合常规施工工艺，从而凸显公共效益。

As a municipal project, we want it cheap in cost. Split Bridge advocates the principle of economy and rapid construction. Low maintenance is also taken into account. Therefore, application of building materials adopts to the standards of Urban Management Bureau: colored asphalt, floor tiles, and metal railing. Besides, due to salty and wet environment by the sea, to ensure anti-erosion of structure, main body of the bridge adopts cast-in-place reinforced concrete structure.

▼桥面使用彩色沥青桥面，地砖，金属栏杆等基础的建筑材料 ©白羽 application of building materials adopts to the standards of Urban Management Bureau: colored asphalt, floor tiles, and metal railing

选择的价值在一个效率优先的时代尤为被忽视，本案设计的巧思是为不经意的步行节点提供了两种路径选择。因此，二分桥也是一个公众参与的行为艺术装置，引发人们对个体意愿作为人文价值的反思。

Nowadays, the value of rights to choose is mostly neglected, and efficiency is over dominating in urban living. Providing two walking modes, Split Bridge is an installation of performance art, which encourage public participant for reclaiming they rights of making choice.

▼鸟瞰，aerial view ©白羽

项目名称：二分桥 Project Name: Split Bridge 项目地址：深圳市盐田区海葵路 Location: Haikui Road, Yantian District, Shenzhen 设计单位：张健蘅建筑事务所 Design Company: Jane Z Studio 主案设计：张健蘅 Designer: Jane JH Zhang 设计团队：Thijs van Oostrum，王诗涛 Design Team：Thijs van Oostrum, Wang Shitao 项目规模：160米 Scale: 160 meters 设计时间：2015年3月 Design Year: March 2015 完工时间：2017年9月 Completion Time: September 2017 主要材料：彩色沥青桥面、地砖、金属栏杆 Main Materials: colored asphalt bridge decks, floor tile, metal railing 业主名称：深圳市盐田区建筑工程事务局 Client Name: Bureau of Construction Engineering Affairs, Yantian District, Shenzhen 项目摄影：白羽 Photographer: Bai Yu