LASSIE: Low life cycle cost Sand-wich Isolation System for Seismic Risk Reduction

Lassie是一种创新、廉价的技术，用于提高地震区结构的安全性和弹性。通过尖端研究、世界一流的英国实验设施、国际合作以及与英国工业的协同作用，它建立在现有研究开发的基础上，以鉴定发达国家和发展中国家的一种新的隔震设计方法。其目的是创造一种新颖的、低成本的滑动隔震系统，这将是新的抗震保护低层建筑设计的巨大飞跃。这项技术将确保超过设计水平的地震的生命安全，并通过保持地震后的完全可操作性显著降低生命周期成本。在许多情况下，地震会导致建筑物下面的地面移动，主要是左右(水平)，因此它会驱动建筑物从一边到另一边(水平)摆动。这些潜在的巨大建筑振动必须以某种方式缓解，通常是通过允许建筑内部发生损伤(以延性变形的形式)来允许建筑吸收这种异常动能来实现的。虽然这种能力设计方法被广泛采用，但在设计水平地震后，它确实给社会带来了巨大的财务修复/重建成本。由于许多大型和重要的基础设施文物“失去使用”而导致的经济低迷，加剧了这一成本。另一种方法是地震隔震系统，该系统寻求在基础水平上将地面与建筑物部分分离。通过允许在地面和建筑物之间的基础水平发生滑动，建筑物从地面“释放”，因此受到的地震激励水平大大降低。因此，这要么极大地减少了结构的损坏，要么使上部结构在设计地震期间保持不受损坏。然而，隔震系统需要昂贵的基础/地下室来容纳它们，尽管目前总体成本正在下降，但人们仍然认为普遍采用隔震系统在财务上是合理的。然而，如果普通住宅的成本能够降低，那么建筑物可以不受强烈地震造成的地面移动的破坏影响的概念将非常有吸引力，因为普通住宅对建筑存量的巨大贡献有效地推动了地震安全成本。因此，这项建议的目的是开发一种低生命周期成本的“夹层”隔震系统，以确保全寿命安全和完全的灾后建筑可操作性。该体系由一个厚厚的钢筋混凝土(RC)地基板组成，该基础板位于一个“沙夹层”(PVC/沙子/PVC)之上，允许在大的地面激励下发生滑动。这种滑移系统的新颖重新定心是通过正常加载的滑索(穿过RC地坪内未灌浆的管道)和一组微桩/锚杆和环梁的组合来实现的。该体系利用了最先进的非光滑非线性动力学理论(滑移-粘结行为)、几何荷载作用下拉索的非线性弹性行为以及微桩群在动力/冲击荷载作用下的土-结构相互作用。在本提案中，新设计的每个元素/组件都应在新启用的“UKCRIC-Bristol土-基础-结构相互作用设施(SoFSI)”EP/R012806/1中进行实验测试，并通过计算确保建议设计的性能在技术准备水平(TRL)框架方法范围内得到验证。

LASSIE is an innovative, inexpensive technology for improving the safety and resilience of structures in earthquake regions. Through cutting edge research, world-class UK-based experimental facilities, international collaboration, and synergies with UK industry it builds upon existing research developments to qualify a new design method of seismic isolation in both developed and developing countries. The aim is to create a novel, low-cost sliding isolation system that will be a quantum leap forwards in the design of new seismically protected low-rise buildings. This technology will ensure life-safety for beyond design level earthquakes and significantly reduce life-cycle costs by maintaining full post-earthquake operability. In many cases, an earthquake causes the ground underneath a building to move, predominately, side-to-side (horizontally) and so it drives the building to oscillate from side-to-side (horizontally). These potentially large building oscillations must be mitigated in some way and typically this is achieved by permitting the building to absorb this aberrant kinetic energy by permitting damage (in the form of ductile deformations) to occur within the building. While this capacity design approach is widely adopted, it does impose a large financial repair/rebuild cost on society after a design level earthquake. This cost is compounded by economic downturns generated by the 'loss of use' of many large and important infrastructure artefacts. An alternative approach is seismic isolation systems which seek to partially uncouple the ground from the building at the foundation level. By permitting sliding to occur at the foundation level between the ground and the building, the building is 'released' from the ground and hence is subjected to a much-reduced level of seismic excitation. Consequentially, this either greatly reduces structural damage or enables the superstructure to remain undamaged during the design earthquake. However, the seismic isolation systems require expensive foundation/basement to accommodate them and, although overall costs are currently reducing, their widespread adoption is still not viewed as universally financially justifiable. Nevertheless, the concept that a building can be uncoupled from the damaging effects of the ground movement produced by a strong earthquake would be very appealing if costs can be reduced for ordinary residential buildings, whose large contribution to the building stock effectively drives the cost of seismic safety. Thus, the aim of this proposal is to develop a low life-cycle cost 'sand-wich' seismic isolation system that will ensure full-life safety and full post-event building operability. This proposed system is composed of a thick reinforced concrete (RC) foundation slab sitting above a 'sand-wich' layer (PVC/sand/PVC) which permits sliding to occur during large ground excitations. The novel re-centring of this sliding system is achieved by a combination of normally loaded, sliding cables (that run through ungrouted ducts within the RC ground slab) and a group of micropile/anchors and ring beam. This system makes use of state-of-the-art non-smooth nonlinear dynamics theory (slip-stick behaviour), the nonlinear elastic behaviour of geometrically loaded cables and dynamic/shock loaded soil-structure interaction of micropile groups. In this proposal every element/component of the novel design shall be tested experimentally in the newly commissioned 'UKCRIC - Bristol Soil-Foundation-Structure Interaction Facility (SoFSI)' EP/R012806/1 and computationally to ensure the performance of the proposed design is validated within a Technology Readiness Level (TRL) Framework methodology.