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

LASSIE是一种创新的、廉价的技术，用于提高震区结构的安全性和弹性。通过前沿研究、世界一流的英国实验设施、国际合作以及与英国工业界的协同作用，它以现有的研究发展为基础，在发达国家和发展中国家都获得了一种新的隔震设计方法。其目的是创造一种新颖、低成本的滑动隔离系统，这将是新型抗震低层建筑设计的巨大飞跃。该技术将确保超出设计水平地震的生命安全，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，地震引起建筑物下面的地面移动，主要是左右（水平）移动，因此它驱动建筑物从一边到另一边（水平）振荡。必须以某种方式减轻这些潜在的大型建筑物振荡，通常通过允许建筑物内部发生损伤（以韧性变形的形式）来允许建筑物吸收这种异常动能来实现。虽然这种能力设计方法被广泛采用，但它确实在设计级地震后给社会带来了巨大的财政修复/重建成本。由于许多大型和重要的基础设施人工制品的“失去使用”而产生的经济衰退，使这一成本更加复杂。另一种方法是隔震系统，它寻求在基础水平上部分地将地面与建筑物分离。通过允许在地面和建筑物之间的基础水平上发生滑动，建筑物从地面上“释放”出来，因此受到的地震激励水平大大降低。因此，这要么大大减少了结构损坏，要么使上层建筑在设计地震中保持完好无损。然而，地震隔离系统需要昂贵的基础/地下室来容纳它们，尽管总体成本目前正在降低，但它们的广泛采用仍然被认为在经济上是不合理的。尽管如此，如果普通住宅建筑的成本能够降低，那么将建筑物与强烈地震产生的地面运动的破坏性影响分离开来的概念将非常有吸引力，因为普通住宅建筑对建筑存量的巨大贡献有效地推动了地震安全的成本。因此，该提案的目的是开发一种低生命周期成本的“三明治”隔震系统，以确保整个生命周期的安全性和事件后建筑的可操作性。该系统由厚钢筋混凝土（RC）基础板组成，位于“夹层”层（PVC/砂/PVC）之上，允许在大型地面激励下发生滑动。这种新颖的滑动系统的重新居中是通过正常加载的滑动电缆（穿过RC底板内的未灌浆管道）和一组微桩/锚和环梁的组合来实现的。该系统利用了最先进的非光滑非线性动力学理论（滑粘行为），几何加载电缆的非线性弹性行为和微桩群的动力/冲击载荷土-结构相互作用。在本提案中，新设计的每个元素/组件都应在新委托的“UKCRIC - Bristol土壤-基础-结构相互作用设施（SoFSI）”EP/R012806/1中进行实验测试，并进行计算，以确保拟议设计的性能在技术准备水平（TRL）框架方法中得到验证。

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.