ZhengZhou stage 1 郑州第一阶段
Zhengdong New District Long Hu Area Sub Central Buisness District C3-10 Plot Office Building Design (ZhengZhou stage 1) – Concept Design -Architectural Design Narrative
The building is characterized by its innovative concept that combines some elements from Chinese traditional architecture (stick-columns) and elements (cables) that are usually employed to stabilize slender structures. A thin ribbed slab constitutes a third structural element, characterized by its lightness. Together they provide an unique structural composition that allows continuous flow of all vertical and horizontal loads up to foundations.
The lightness of this structure will allow a new spatial experience for the people working and staying here. The slabs of each level will leave a floating impression. Transparency becomes an overall option for the user of this building.
The view of the steel cables and concrete columns give an ever changing impression from one level to the other instead of a monotonous structural repetition An endless of the structural composition is the highlight of the building. This new structure will offer an endless variation in the composition of structural elements.
The horizontal loads are undertaken with the cables, positioned outside the building. This system, used to nowadays for the stabilization of the slender antenna pylons, permits complete flexibility of the towers floors, constituted only by the columns and the ribbed slabs.
In order to increase their efficiency and to decrease the shift of the building, the cables are pre-stressed. This permits that all cables are effective in takingthe loads. Their force due to horizontal loads will in some cases increase and in some cases decrease, but the cables would remain in tension
The increase of the number of columns is followed by the increase of the number of cables. In that way the rotation and the shift of the building in the lower floors is well controlled. In upper floors, where the bigger wind forces appear, the cross section of the cables is increased.
The cables are connected with the floor beams using steel connectors. The presence of the beams in the anchor points is favorable in order to introduce horizontal and vertical forces coming from the cable. In the lower anchor point the cables are connected with the beams and columns in the parking level.
As opposed to “classical” structural systems characterized by vertical repetition of the structural elements and their gradual scaling with the increase of the building weight, the proposed building solves this problem basically by the introduction of new vertical columns in the lower floors. In that way lower floor’s load is introduced in new columns but also the forces of upper columns, thanks to compatibility of deformations, are redistributed. The redistribution of the vertical loads is mainly achieved by the beams under the slabs. In the lower and upper zone of the tower, the slabs are omitted in order to make open public space. This omission helps to reduce the load on the central columns, horizontally stabilized with the retained beams.
The columns are prefabricated. They are made out of reinforced concrete or if local experience requires in embedded steel sections. The prefabrication helps to increase the capacity of the columns. In this way the architecture requirements that demand slender elements are met. The load between reinforced concrete columns is transmitted across the steel bars or across steel profiles if they are embedded. In Switzerland but also across Europe very good experiences are made with prefabricated columns. The decrease of the construction time with this system is considerable.
Space constitution, Building function
The center of most office tower is closed and massive. In this structural proposal the center, the very heart of the building, can be an open, usable space.
The center of the building is not separating each side of the building from another but brings people working in different areas of the same level together. On the ground floor and at the top of the building this area becomes a void over several levels, where people can meet.
The concept of the structural design gives plenty of new possibilities to the use of an office tower. Even if the core would be placed at its most usual location in the middle in the floor plan, this concept could also offer, as an alternative, an atrium with vertical glazed shafts. The heart of the building will become transparent and light. For total flexibility the shafts could also be located at the outside of the building. The interior space would become totally open without any interruption by any structural wall.
The center of each floor plan could provide a view to the outside. Through this open space people could look from one side to the other side of the building.
ZhengZhou stage 2 郑州第一阶段
通常来说，建筑每一层的承重是不一样的。我们设计的郑州120米塔楼中，一共有30层，也就是说，底层的受 重是第三十层的三十倍。为了避免增加结构（柱子或核心筒）的尺寸，我们改变结构柱的数量——柱子数量由上至下递增。在郑州第一阶 段（概念阶段中），为了创造一个轻盈的结构体系但同时保证结构的稳固性，我们在高层的外部设计了拉索结构以承受拉力（高层内部直 柱承受压力）。由于外部的拉索结构会带来消防扑救的问题，在郑州第二阶段（方案阶段）设计中，我们把上一个阶段中的直柱与拉索系 统整合为斜柱系统。这个斜柱结构系统同时抗压与抗拉。斜柱的数量也随着层数的增加而递减。在里面人们可以在每一层都体会到不同， 而不象传统的高层，每一层的体验几乎是相似的。
Zhengdong New District Long Hu Area Sub Central Buisness District C3-10 Plot Office Building Design (ZhengZhou stage 2) – Concept Design -Architectural Design Narrative
The building weight changes from one level to another with the height. In our tower of 30 levels the load is 30 times greater on the ground level than on the top floor. Instead of increasing the size of the columns or the cores, we increased the number of columns. To maintain the minimal dimension of construction elements and lightness of the building, we reinforced in the previous design stage, the building with stiffening tension wires on the outside.
Our new design reduces the amount of structural elements to one single element, a pair of inclined columns. These inclined columns support and stiffen the building simultaneously. The amount of these triangles decreases with the height of the building. Therefore, density of structural elements will change over the entire height of the CBD Bank Tower. The structural height condition will be experienced in every part of the building and create an endless variety of spatial impressions for people working or just having meeting there.
Previous issues concerning fire access in the previous scheme allowed us as a chance to enhance the architectural rigor of the basic idea in the previous design stage.
The structural concept of the Zhengzhou tower is best understood by analyzing the structural concepts of the Eiffel Tower. When the engineer Maurice Koechlin designed the Eiffel tower, he conceived it as a funicular structure, optimized to undertake the wind load with its optimal form. This structure can be reduced to group of triangular elements that take the horizontal load on different heights of the building. Although these triangular are stable only in one plane, they can be repeated and placed in other planes in order to stabilize the building in all directions. Inclining the plane is possible as other inclined planes help to stabilize it. The Zhengzhou tower is designed from these basic principles.
This structural system creates a building that is structurally lighter than a conventional structure with heavy cores and thick columns. The comparison shows that our proposal will be far lighter, even with the same structural stiffness and floor areas. Only if the price of steel is may be seven times more than the cost of concrete, the costs for building material are still comparable. This building might require more labor to build, but the building’s use of material resources justifies the effort. This light structural system will be exposed and present in every part of the building, and the thin inclined columns create a nuanced variety throughout the entire building.
The 120m tall office tower in ZhengZhou Sub Central Business district represents a bank company. It consists of 30 cantilevering platforms stacked on top of each other. The supporting beams are exposed and visible from far away. Visitors might be reminded visitors of wooded structures from China’s ancient empire. because this building is composed of an endless series of small and fully exposed structural elements as you find them for example in pagoda towers, which then fully increased into the large scale of contemporary Chinese urban development. This new office tower is the first in a row of buildings to be designed by world famous international architects and attempts to challenge and provoke conventional high-rise designs in many ways. It is not new by its shape nor by adding any new details to old designs. It is rather questioning as basic as possible the spatial and structural arrangement of an office tower. While most big high rise building are achieving stiffness through massive cores or facades with braced elements, this high-rise in contrast consists only of one singular structural element; a series of inclined columns combined to make structural triangles, that carry the load of the building and stiffen the volume. It will offer an open platform without closing facades or occupying the center of the floor. The structure in this building is not hidden, it is exposed, and experienced in every part of the building. The strength of the steel tubes running through the entire volume will connect and differentiate each space in this building. These structural tubes in effect create an endless variety of office rooms, which break the monotony often found in generic work spaces. With its increase in density at to the ground level and its increase of beam dimension to the top the structural system allows for increasing cantilevering slabs as you ascend. Through these structural conditions the building height can be indicated at each level. In this sense, stability becomes literally an experience in every single space of this bank building. Some of these inclined columns go through the façade and spread out on the ground floor. These columns, visible over many levels up to 100m, with a diameter of only 40 cm will give the building in a discrete and elegant way, a monumental impression. Since these columns exposed on the front of the glass façade are only making up a very small part of the visible building structure; they will remain mysterious and attract people walking by to come closer to reveal the meaning of these oblique columns.
大多数传统办公楼的中部空间都是封闭并且庞大的，而这个设计的中部空间却是完全开放的，可使用的。封闭的中部 空间使得办公空间被分割开来，而开放的中部设计却让办公的人都可以集中到中心来，从而增加公司凝聚力，让员工之间有更多交流的机会。中部空间在一层与顶层变成了通透的中庭，人们可以在此相聚，此结构设计 可以让塔楼的内部空间灵活多变。明亮开放的中庭空间使分布在四周的电梯可以有敞亮的视野。人们可以徜徉在底层的中庭与26层的VIP开放空间中，享受花园，无遮拦的视野与高广的空间，这些空间被环绕在内，免受高层的强风侵袭，非常怡人。每层楼的中心都可以通过VIP休息区和宴会厅看到外部。
Narrative of building function
The centers of most office towers are closed and massive. In this structural proposal, the center, the very heart of the building, can be an open and usable space. The center of the building is not separating each side of the building from another but brings people working in different areas on the same level of the building together. On the ground floor and at the top of the building this area becomes a void over several levels, where people can meet. The concept of the structural design gives plenty of new possibilities to the use of an office tower. Instead of a closed heavy shaft in the middle of the building, this structure offers an alternative, an atrium with vertical glazed elevators. The heart of the building will become transparent and light. The center of each floor plan could provide a view to the outside. Through this open space, working people could look on one side of the building to the other side of the building.
A large atrium opens the structure on the entrance level of this building while two open court yards in the VIP area on top of the building offer people a place to meet on the 26th floor in a garden well protected from winds, enjoying a view through the lounge area and banquet hall.