新木造塔楼研究成功通过测试验证

Developing sustainably constructed buildings is an urgent concern as cities look to decrease their ecological footprint. Skidmore, Owings &Merrill LLP (SOM) sought to address this issue by exploring the potential of mass timber to reduce the embodied carbon footprint of high-rise buildings. The Timber Tower Research Project, funded by the Softwood Lumber Board (SLB) and launched in 2013, examined solutions that could utilize mass timber as the main structural material to reduce the embodied carbon footprint of buildings by 60 to 75 percent compared to a benchmark concrete building. The research team proposed a structural system called the Concrete Jointed Timber Frame, a system which employs mass timber for main structural elements and reinforced concrete for connections. This approach was further developed in a second report in 2014 that focused on gravity framing systems and recommended a physical testing program.

随着城市希望扩大生态足迹，设计以可持续性方式建造的建筑也就成为需迫切考虑的问题。SOM希冀发掘层压实木减少高层建筑隐含碳足迹的潜力，从中寻求解决方案。木造塔楼研究项目由软木材组织（SLB）出资，于2013年启动，检验了用层压实木作为主要结构材料的做法，验证了可使建筑隐含碳足迹比基准混凝土建筑减少60%到75%。研究团队提出一种称为“混凝土节点木框架”的结构系统，该系统使用层压实木建造主要结构元素，用钢筋混凝土制作接缝节点。这个方法在2014年的第二次报告中得到进一步深化，报告重点研究了承重框架系统，并推荐了一套物理测试程序。

To advance the findings of the research initiative, SOM and Oregon State University (OSU), with support from the Softwood Lumber Board, developed a comprehensive physical testing program that, to date, has included nearly 20 tests of varying sizes and configurations. On August 8th, the successful test of the final full-scale specimen provided strong evidence that the timber-concrete composite system can satisfy code requirements and compete with traditional construction methods.

为了推进研究结果，SOM与俄勒冈州立大学（OSU）在软木材组织的支持下，研发了一套综合物理测试程序，至今已包括近20项各种尺寸和构造的试验。最终的全比例样板于8月8日成功通过测试，有力地证明了木材-混凝土组合系统可满足规范要求并可匹敌传统建造方式。

The tested floor specimen—36 feet long by 8 feet wide—was modeled on a portion of a typical structural bay. The tested element was a Cross-LaminatedTimber (CLT) deck topped with a thin layer of reinforced concrete to enhance the structural, acoustic, and fire performance of the system. The two materials were joined and made composite with connectors specifically designed for this application. The reinforced concrete topping slab was thickened at the supporting CLT beam to form a rigid connection between CLT decks, a feature which allows floors to span between beams with a relatively thin cross-section. For the test, the specimen was loaded with a hydraulic actuator and was recorded by 48 different sensors over the course of two hours.

地板测试样本长36英尺（11米），宽8英尺（2米），是按典型结构开间的一部分制作的样板。所测试的元素是交错层压木材（CLT）楼承板，上面铺薄薄一层钢筋混凝土，以加强系统的结构、隔音、防火性能。两种材料用为此应用特别设计的连接件连接，形成组合楼板。钢筋混凝土面层楼板在起支撑作用的CLT梁的位置加厚，在CLT楼承板之间形成刚接，让地板跨于梁之间的横截面可以相对较薄。测试时，样板上安装了液压执行器，在整个过程的两小时内用48个不同感应器记录测试。

The floor system provided greater stiffness than required by code and supported an ultimate load of 82,000 pounds—approximately eight times the required design load. The initial results are promising and will serve as the basis for verification testing—a series of tests that will address issues such as fire resistance—which will be required before the system can be used in high-rise buildings.

地板系统的刚度大于规范要求，最终支撑了82,000磅（37,000公斤）的荷载——约为所要求的设计荷载的八倍。最初结果很有希望，将成为验证测试的基础。验证测试是一系列针对防火等问题的测试，系统须通过验证测试才能用于高层建筑。

SOM Associate Benton Johnson remarked that the successful test“highlights the real benefits of the composite timber approach. We took a small amount of concrete that was necessary for acoustic and fire performance and used it to enhance the structural performance of the floor. This move allows mass timber to reach its full potential, allowing it to compete in the market while also reducing the carbon footprint of cities.”

SOM的理事BentonJohnson表示这次测试成功“彰显了组合木材方法的真正优势。为隔音和防火性能必须使用混凝土，我们用这少量的混凝土加强了地板的结构性能。这个做法让层压实木充分发挥潜力，在市场上具有竞争力，同时减少城市的碳足迹”。