2013 Session: AFF60

• Quality Management and Assessment of Shotcrete Liners with Sonic Methods
  Abstract: Shotcrete liners are being utilized more frequently in transportation infrastructure as retaining structures and tunnel covers. Despite their economic advantages to portland cement concrete, the initial quality of construction and long-term durability of shotcrete liners are of concern among some highway agencies. The need for a quantitative construction quality management methodology to ensure adequacy and uniformity of strength and thickness is desirable. Shotcrete liners should be tested periodically in critical structures to assess possible material deterioration and to detect the onset of defects such as delamination and voids. The impact echo and ultrasonic surface wave methods are two nondestructive sonic methods that are effective for those purposes in concrete structures. The effectiveness and challenges of applying these methods to shotcrete liners are investigated in this paper. To that end, several 6 ft by 6 ft slabs made of concrete and shotcrete with different thicknesses and in some cases with embedded defects were evaluated. Unlike concrete slabs, shotcrete slabs exhibit some spatial heterogeneity. In addition to heterogeneity, surface roughness of shotcrete adds some complications into data interpretation in terms of thickness estimate. Despite these challenges, results from this study demonstrate that delamination and voids within the shotcrete liners can be detected well by using these sonic methods.Keywords: shotcrete, concrete, delamination, nondestructive testing, impact echo, surface wave.
  Authors: Azari, Hoda; Nazarian, Soheil; Yuan, Deren
  Authors: Azari, Hoda; Nazarian, Soheil; Yuan, Deren
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Design
  Session: AFF60
  Paper Number: 13-1084
• A Physical Model Study on the Ground Settlement Caused by Tunneling in Sand
  Abstract: A physical model test on the ground settlement caused by tunneling in sand was conducted in this study. A large-scale custom-made physical model box with a lowering basement was used in this paper to simulate the tunneling. Analysis of the test results, it was found that the volume of the settlement trough was not constant and varied with the depth. An empirical equation was proposed to express the relationship between the volume of the settlement trough and the depth. Finally, a method for estimating the subsurface ground settlement of tunneling in sand was established considering the volume variation of the settlement trough with depth.
  Authors: Wang, Fei
  Authors: Wang, Fei
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Design
  Session: AFF60
  Paper Number: 13-1729
• Laboratory Test of the Fire Protection Layer Used in the Soil-steel Tunnel in Poland
  Abstract: Flexible corrugated steel culverts have been used in engineering for many years, with the first application in 1931. Since that time, the popularity of these structures has increased enormously. Soil-steel bridges are more and more used as road and railway tunnels and heightened interest on the issue of structural fire protection of tunnels.In summer 2012 the tunnel built of the steel corrugated sheets were constructed in Karpacz city in Poland. The structure served as road tunnel under ski slope. A 100 m long tunnel is a metal open arch with a span of 11.15 m and a rise of 6.50 m. The steel tunnel with the fire protection is a first buried structure in Europe. This paper describes laboratory tests of protection layer during experimental fire tests. The main goal of conducted laboratory fire tests was to evaluate the steel structure with fire protection layer in configuration of part tunnel structure. Temperature on the surface of the steel plates and deflections in metal plates were measured. The instrumentations included temperature gauges installed on the metal plates and a device to monitor deflections of the structure. The experimental results obtained during measurements are shown in graphs/tables.The research project is sponsored by ViaCon Company and Torkret Company in Poland.
  Authors: Kunecki, Bartlomiej
  Authors: Kunecki, Bartlomiej
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Design
  Session: AFF60
  Paper Number: 13-3015
• Nondestructive Evaluation Of Concrete Linings At Hanging Lake Tunnel
  Abstract: Tunnel lining evaluation is performed in the Hanging Lake Tunnel near Glenwood Springs, Colorado, using variations of four nondestructive evaluation (NDE) methods: air- and ground-coupled ground penetrating radar (GPR), ultrasonic echo (US echo), ultrasonic tomography (UST), and impact echo (IE). Potential regions of interest are identified using high-speed air-coupled GPR and visual inspection. A robotic frame with pneumatically-operated vacuum plates was used to automate the ground-coupled GPR, US echo, and IE tests, while the UST technique was used manually. This study shows that a particular combination of NDE techniques is a powerful tool for assessing the condition of tunnel linings and can detect potential anomalies such as delamination, depth of surface cracks, reinforcement depth and layout, and lining thickness. By mapping the phase shift of the ultrasonic pulses at detected interface, the potential bonding of layer interfaces and reinforcement is assessed.
  Authors: White, Joshua; Wolf, Julia; Shokouhi, Parisa; Hurlebaus, Stefan; Wimsatt, Andrew James
  Authors: White, Joshua; Wolf, Julia; Shokouhi, Parisa; Hurlebaus, Stefan; Wimsatt, Andrew James
  Year: 2013
  Document Type: Paper
  Subject: Bridges and Other Structures; Design
  Session: AFF60
  Paper Number: 13-3362
• Quality Management and Assessment of Shotcrete Liners with Sonic Methods
  Authors: Azari, Hoda
  Authors: Azari, Hoda
  Year: 2013
  Document Type: Presentation
  Session: AFF60
  Paper Number: 13-1084
• Nondestructive Evaluation Of Concrete Linings At Hanging Lake Tunnel
  Authors: White, Joshua
  Authors: White, Joshua
  Year: 2013
  Document Type: Presentation
  Session: AFF60
  Paper Number: 13-3362