A Seattle bridge closed due to worsening cracks in March will stay closed through at least 2021, according to the Seattle Dept. of Transportation. The agency says a contractor will fix a bulging bearing on Pier 18 of the cracking West Seattle Bridge before it can move forward and see if the 36-year-old bridge is salvageable.

SDOT董事Sam Zimbabwe说,一旦轴承修理了轴承,SDOT将“增加额外的支撑,以确保桥梁不会在其自身的重量下破裂。”他说:“然后,我们可以理解我们需要做的事情来支撑桥梁并修理它,我们还不知道这在技术上或财务上是可行的。”“每个步骤都将帮助我们更好地了解下一步。”

西西雅图桥的裂缝恶化,这是一个长达2,600英尺的高层建筑并宣布了一项计划,雇用北美克雷默(Kraemer)修理码头18码头。

津巴布韦说,稳定桥梁的下一阶段要建造支撑物将需要“需要制造的独特设备和材料”。他不希望工作能够在2020年下半年进行,但是该阶段的大部分工作将取决于第一阶段的进行方式。

Taking vehicles off the bridge has slowed the cracking, but not stopped it. Fixing the bridge’s Pier 18 and shoring the bridge may bring clarity to a fixable solution, and SDOT says it hopes to understand possible scenarios with the help of a technical advisory panel of experts from around the country.

西雅图市长珍妮·杜尔坎(Jenny Durkan)说:“我们在这个项目上仍然不知道很多意外事件,我们不确定全部原因。”“在码头18上固定轴承将使桥梁可以弯曲和移动,但是我们不确定在修复时将显示什么数据。我们没有特定的时间表和成本。”

SDOT警告说,任何潜在的解决方案都可能只为失败的结构增添10年的生命。低矮的桥梁保持开放,仅用于运输,货运和紧急车辆。

西雅图使用紧急签约授权选择克雷默(Kraemer)作为现在认为是西西雅图高层桥梁稳定的第一阶段。第一步是删除交通,第一阶段的第二步是修复桥东侧的码头18码头的横向轴承。

The second phase will add temporary external structures to shore the bridge so experts can continue to assess repair feasibility, timeline and cots. The third phase, long-term repair, is not yet a certainty.

在紧急合同中,SDOT放弃了所有有竞争力的招标要求,并于4月13日与六名承包商联系。克雷默(Kraemer)最近在华盛顿州运输部的Duwamish River Bridges项目中工作,并了解了附近以及美国海岸警卫队的允许。要求,SDOT说。克雷默西北部总部位于西雅图。SDOT发言人说,根据该协议,克雷默(Kraemer)在有限通知下未签订合同的工作。根据州法律,可以在签订合同之前开始工作,并“随着维修设计的发展,将在不久的将来进行合同。”

Kraemer will replace the lateral bearings on the east end of the bridge, bearings that allow the bridge to expand and contract with temperature and loading changes. The bearings—rectangular pieces of synthetic rubber neoprene—act like a cushion to separate the box girder from the column cap . The bearings at Pier 18 are currently compressed and bulging, restricting movement of the bridge and creating additional pressure on the surrounding area. “That bearing is not moving,” Zimbabwe says, “and is transferring stress through the bridge.”

SDOT预计可能需要几个月的时间来确定修复轴承的最佳方法,其中可能包括工作区域周围的临时平台和专用设备,以精确轴承周围的混凝土,放置新的轴承并倒入新的混凝土。克雷默(Kraemer)还将对稳定设计进行可构成审查,以确定它可以轻松地构建和提供输入。克雷默将评论推迟给SDOT。

目前的工作已经从设计团队开始,该团队涉及审查与SDOT合同的WSP工程师生产的设计。此外,克雷默(Kraemer)的项目负责人开始制定建设,健康和安全,设备和材料采购,工作时间表和时间表的计划。SDOT发言人说:“一旦设计完成,已获得许可并采购了定制材料,建设将开始。”

如果需要,SDOT还宣布了紧急情况下的紧急撤离计划的计划。

If during Phase 1 engineers determine the bridge structure is irredeemably compromised, Phase 2 may still proceed so that temporary shoring prevents any potential failure while plans get made for demolition and replacement. SDOT also says that releasing Pier 18 bearings and temporary crack arrest measures may stabilize the bridge enough to that shoring isn’t needed if the city decides to move straight toward demolition.

这座桥已经监控regularly since 2014. In 2019, the federal load rating for this type of bridge was changed, and SDOT initiated a new review. As a result, the transportation agency has regularly inspected concrete cracks.

这座桥最初是针对每个方向行驶的三条车道设计的,但扩展到了三条西行车道和四个东行。纽约市说,增加的流量,加上商用车的规模和重量增加,加剧了长期维护挑战。此外,80%的负载是死负荷,因此即使没有流量,也可能恶化。