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

LASSIE：生命周期成本低的夹层隔震系统，可降低地震风险

• 批准号: EP/X010074/1
• 负责人: Nicholas Alexander
• 金额: $ 94.91万
• 依托单位: University of Bristol
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FX010074%2F1
• 关键词: LASSIE; Low; life; cycle; cost

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.

LASSIE 是一种创新、廉价的技术，用于提高地震地区结构的安全性和复原力。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，它以现有的研究进展为基础，在发达国家和发展中国家验证了一种新的隔震设计方法。其目的是创建一种新颖的、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的地震时的生命安全，并通过保持完整的震后可操作性来显着降低生命周期成本。在许多情况下，地震会导致建筑物下方的地面移动，主要是左右（水平）移动，因此它会驱动建筑物左右（水平）振动。这些潜在的大的建筑物振动必须以某种方式减轻，通常这是通过允许建筑物内发生损坏（以延性变形的形式）来吸收这种异常动能来实现的。虽然这种容量设计方法被广泛采用，但在设计级地震后，它确实给社会带来了大量的财政修复/重建成本。由于许多大型重要基础设施的“无法使用”而导致经济衰退，这一成本更加严重。另一种方法是隔震系统，该系统试图在地基层面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层发生滑动，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，这要么大大减少了结构损坏，要么使上部结构在设计地震期间保持完好无损。然而，隔震系统需要昂贵的地基/地下室来容纳它们，尽管目前总体成本正在降低，但它们的广泛采用仍然不被认为在经济上是普遍合理的。尽管如此，如果能够降低普通住宅建筑的成本，那么建筑物可以免受强地震产生的地面运动破坏性影响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高了抗震成本安全。因此，该提案的目的是开发一种生命周期成本低的“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全面可操作性。该系统由位于“三明治”层（PVC/沙子/PVC）上方的厚钢筋混凝土（RC）基础板组成，允许在大地面激励期间发生滑动。该滑动系统的新颖的重新定心是通过正常加载的滑动电缆（穿过 RC 地面板内未灌浆的管道）和一组微型桩/锚和圈梁的组合来实现的。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）、几何负载电缆的非线性弹性行为以及微型桩群的动态/冲击负载土壤-结构相互作用。在本提案中，新颖设计的每个元素/组件均应在新委托的“UKCRIC - 布里斯托尔土壤-基础-结构相互作用设施（SoFSI）”EP/R012806/1 中进行实验测试，并进行计算测试，以确保拟议设计的性能在技​​术准备水平 (TRL) 框架方法中进行了验证。

项目成果

Experimental determination of friction at the interface of a sand-based, seismically isolated foundation

砂基隔震地基界面摩擦力的实验测定

• DOI: http://dx.10.1007/s00707-023-03802-0
• 发表时间: 2023
• 期刊: Acta Mechanica
• 影响因子: 2.7
• 作者: Sezer Y