A concrete tower and related formwork and related method of construction

摘要

Tower structures, such as for supporting wind turbine nacelles, can be manufactured by a number of techniques. Such towers may commonly have a frustoconical inner and/or outer surface, narrowing along their height. Pre-fabricated or pre-cast constructions require transportation and large cranes for assembly. In-situ cast structures avoid transportation, but may still require the use of mobile cranes. In-situ casting can also be time-consuming and thus costly. The present invention relates to an improved apparatus for constructing by progressively higher concrete composition forms a tower structure, and method of doing so. A collar assembly is provided, which comprises a higher subassembly, lower subassembly, and jacking arrangement. The higher subassembly comprises a crane for shifting formwork pods, normally from the ground, to within the higher subassembly. Concrete can be poured into the formwork and set to form the next higher zone of the tower. Removed formwork can be lowered to the ground by the crane. The higher and lower subassemblies can selectively index to a zone of the tower being formed by engagement to abutment formations of the tower. The jacking arrangement can raise one of the subassemblies while the other is indexed to abutment formations of the tower. By this means the collar assembly may lift itself to allow pouring of the tower at new heights. The formwork pods comprise an inner and outer formwork, and a different set of outer formwork is used for each zone of the tower. The abutment formations to which the subassemblies may index to are formed by the formwork pods.