WSP USA设计的下水道隧道将是圣路易斯建造的最长

在圣路易斯地区有史以来最长的下水道隧道项目（由WSP USA设计的项目）开始了建设。

在2024年完成后，这条6.8英里长的下Meramec隧道将增强该地区的下水道网络，并改善大都会圣路易斯地区南侧的Meramec河流域内的水质。

1.74亿美元的隧道位于圣路易斯县南部，将穿越一个包括日落山和芬顿城市的地区。覆盖层的深度范围为78至286英尺，在很大程度上由表面地形控制。挖掘的隧道直径计划为14.5英尺，内径为8英尺。

“The main objective of the tunnel is to intercept flows and to take offline the interim Fenton Wastewater Treatment Facility,” said Everett Litton, project manager for WSP. “The tunnel will be constructed entirely in rock and is anticipated to operate under both open channel and submerged hydraulic flow conditions.”

WSP provided preliminary and final design services for the Metropolitan St. Louis Sewer District (MSD) and will continue to provide engineering services throughout construction. WSP is working with HDR, the prime consultant for this project.

WSP is the lead tunnel design firm with responsibilities related to design of the deep tunnel, specifications for the tunnel boring machine, drop structure design, geotechnical engineering and design, risk identification and preparation of the geotechnical baseline report.

Design work was completed in 2020, and construction began in January 2021.

MSD serves approximately 1.3 million residents and is the fourth largest wastewater collection system in the U.S.

全面的倡议

In 2011, MSD began implementation of Project Clear, a complex 23-year, $4.5 billion capital improvement program for its sewer system to protect public health and safety while ensuring compliance with regulatory issues and requirements, which includes the Lower Meramec Tunnel project. It is part of the MSD consent decree program, an agreement established with the U.S. Environmental Protection Agency.

在以前连接下Meramec隧道的鲍姆加特纳隧道建筑中，以前遇到了大量的地下水流入。作为下Meramec隧道的设计过程的一部分，WSP进行了一项全面的，分阶段的岩土研究计划，以减轻项目风险，并在每个深度井眼中进行广泛的包装工渗透性测试，并在关键项目地点进行含水层测试。

To quantify the amount of anticipated groundwater expected within the excavated tunnel and shafts, data from 493 packer tests were utilized to baseline an adequate inflow for bidding purposes.

“Based upon prior tunnel construction, the geologic conditions within the project area are prone to significant groundwater inflows,” Litton said. “The Lower Meramec Tunnel project will ultimately help eliminate the discharge of the interim wastewater treatment facility as part of the Missouri Department of Natural Resources’ long-term plan for the region. The project will help consolidate and simplify MSD’s wastewater treatment plant operations.”

新隧道将连接到现有的Baumgartner隧道，并包括Fenton Construction Shaft的建筑；在Baumgartner施工轴上安装最终衬里；建造六个液滴结构，包括近地表结构，滴轴，排气轴，停用腔室和隧道Adits（矿山入口）；在芬顿建筑轴上安装舱壁；拆除现有的泵站；和近表面下水道连接到掉落结构。

“The six drop structures are included within the design to accommodate as much gravity flow to the tunnel as is practical and economical,” Litton said. “Four types of drop structures were considered: tangential vortex, vortex with helical ramps, plunge inlet and baffle type drop structures. Both plunge and tangential vortex drop structures were considered suitable and utilized for the project.”

环境利益

下Meramec隧道项目中将一些值得注意的设计元素纳入了该项目的环境要求。

在隧道遗址附近的一个先前废弃的废水泻湖被重新使用，用于存储约352,000立方码的挖掘岩石，称为隧道泥浆。

利顿说：“这种重新装修的泻湖消除了29,300辆自卸车旅行，从这些旅行的磨损中节省了当地的道路。”“随着燃油消耗和卡车处理的减少，这将为该项目的碳足迹大大减少。”

此外，规定了玻璃纤维增​​强管，以适应该隧道计划的100年生命周期，与所考虑的其他替代品相比，隧道本质上更长且更可持续。

The project is using funds from Missouri’s Clean Water State Revolving Fund (SRF), a loan program that provides low-interest financing to construct wastewater and stormwater projects that improve water quality. At the time of bidding, the Lower Meramec Tunnel was the largest SRF project in Missouri history.

为了达到这一点，在整个设计中，所有利益相关者之间的所有利益相关者之间都需要与几个公用事业，机构和市政当局进行协调。在整个设计阶段，举行了公开会议，以讨论项目走廊沿线的房主担忧。

Litton has appreciated the opportunity to work on a project that will have a major impact on the health and safety of his community.

“I enjoy contributing to projects with grand ambition and those that provide tangible benefits to the environment and community,” Litton said. “I’ve personally skied, fished and kayaked the Meramec River and am grateful to be involved in Project Clear. I am incredibly proud to be involved in such a wonderful project with an amazing team that will ultimately help to improve the rivers and streams in my hometown.”

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