The Gilberto Borja Navarrete Viaduct under construction in a steep, forested valley, June 2012. A concrete deck curves away from the viewer on very tall rectangular concrete piers. Near the camera, blue steel formwork sits under the deck beside the abutment. Tower cranes stand beside the piers, a muddy river runs along the valley floor, and dirt access roads cut across the hillside on the right.
The viaduct during construction, June 2012, looking north. Resized from the original for web display.
Photo: HighestBridges, via Wikimedia Commons, CC BY-SA 3.0.
Section 01✓ Free

The Project

Gilberto Borja Navarrete Viaduct (formerly San Marcos Viaduct), Puebla, Mexico. Built 2009–2012; opened to traffic September 2014. Source: the design team's paper in Hormigón y Acero, 2015.

208
METRES
Pier 4 height
850
METRES
Viaduct length
64
PILES
Original piles under pier 4, Ø1.5 m
14 of 64
PILES
Unaltered on sonic testing (22%)
+14
PILES
Supplementary piles, Ø1.20 m
6,000
CUBIC METRES
Pile cap, cast over four days

Figures: Arribas Mazarracín et al., Hormigón y Acero 66(275), 2015.

Work on the Gilberto Borja Navarrete Viaduct began in March 2009 with the foundations of its tallest pier. The viaduct, formerly the San Marcos Viaduct, carries the Nuevo Necaxa–Ávila Camacho section of the Mexico City–Tuxpan corridor across the San Marcos River valley in Puebla. Design and construction were awarded to CONNET, a joint venture of FCC Construcción and ICA.

The deck is 850 m long, with spans of 57, 98, 3×180, 98 and 57 m. Pier 4 stands 208 m above the valley floor; at the time of construction it was the tallest pier built in a balanced-cantilever bridge, according to the design team's paper.

Five piers stood on shallow footings. The sixth needed 64 piles.

This is not a story about the tallest pier. It is a commercial exposure created when an early-warning test runs after the batch it was meant to warn on.

Pier 4 sits on a meander of the San Marcos. Rock outcropped across one quarter of its footprint; the rest was alluvial sand and gravel to a depth of 20 m. The design called for 64 piles, 1.5 m in diameter, bored behind a temporary embankment. The embankment allowed work while river flow stayed below 1,000 m³/s, which gave a working season from December to May.

The design specified sonic testing as soon as the first few piles were cast, to catch problems in the construction procedure. A series of hindrances delayed the tests until all 64 piles were finished in July 2009. Only 14 piles (22%) were unaltered. Cores and a pile-by-pile recalculation then allowed 53% of the piles to be accepted. The paper says the cause of the defects could not be clearly established.

Piles with insufficient capacity were injected with grout. The work was suspended when the river rose and finished in March 2010, but it did not repair enough piles for the foundation to perform as required. In May 2010 a reinforcement of 14 further piles was designed, 1.20 m in diameter and cased throughout. They were completed in June 2010.

The 34 m × 34 m pile cap, 6,000 m³, was then cast continuously over four days, with ice flakes replacing part of the mixing water, so that shaft work could start before seasonal flooding.

The paper states that the pier 4 deck conditioned construction time. That deck was completed in September 2012, the main structure in November 2012, and the section opened to traffic in September 2014.

⚙️ Pier 4 foundation — before and after strengthening

GILBERTO BORJA NAVARRETE VIADUCT · PUEBLA, MEXICO · 2009–2012 Pier 4 foundation: the early test ran after the full batch ELEVATION · 850 m · SPANS 57 · 98 · 180 · 180 · 180 · 98 · 57 m P1 · 33 m P2 · 76 m P3 · 166 m P4 · 208 m P5 · 121 m P6 · 54 m Mexico City Tuxpan Only deep foundation River meander · alluvium to 20 m P1–P3, P5–P6: shallow footings BEFORE · JULY 2009 64 piles, Ø1.5 m, bored behind a temporary embankment Pile cap not yet cast Alluvium 0–20 m Rock Sonic test result: 14 of 64 piles unaltered (22%) After cores and recalculation: 53% accepted. Specified: after the first few piles. Actual: after all 64, July 2009. AFTER · STRENGTHENED FOUNDATION Original piles retained; 14 supplementary piles interspersed Pile cap 34 × 34 m · 6,000 m³ · cast after supplementary piling Alluvium 0–20 m Rock 64 original piles Ø1.50 m + 14 supplementary piles Ø1.20 m Grouting finished March 2010; not enough piles repaired. Reinforcement designed May 2010; piles completed June 2010. Supplementary piles permanently cased throughout. Mar 2009 Pier 4 piling starts Jul 2009 All 64 piles done · first sonic results Mar 2010 Grouting complete May 2010 Reinforcement designed Jun 2010 Supplementary piles complete MILESTONES · NOT TO SCALE grouting suspended by river rise EXPOSURE [units needing extra investigation] × [cost / unit] + [units needing remedy] × [remedy cost / unit] + [extra delay months, counted once] × [your time-related cost / month] Illustrative framework. The paper reports no project costs and no allocation of liability. Altered on sonic test No anomalies on sonic test Supplementary pile; outline = permanent casing Original pile, individual status not shown Schematic, not to scale · Representative piles in sections; count strips show totals, not locations · Source: Arribas Mazarracín et al., Hormigón y Acero 66(275), 2015

Schematic, not to scale; sections show representative piles and count strips show totals, not locations. Exposure formula is illustrative. Diagram: Original — EE&HL Network 2026 · Tap or click the diagram to open it full size.

⚙️ Pier 4 Foundation — Sequence (Published Record)

  • Mar 2009 — Pier 4 foundation works begin, behind a temporary embankment.
  • Jul 2009 — All 64 piles complete. Sonic tests run: 14 unaltered (22%).
  • Then — Cores and pile-by-pile recalculation: 53% of piles accepted.
  • Mar 2010 — Grout injection finished, after a suspension when the river rose. Not enough piles repaired.
  • May 2010 — Reinforcement of 14 supplementary piles designed.
  • Jun 2010 — Supplementary piles completed.
  • Then — Pile cap cast continuously over four days.
  • Sep 2012 — Pier 4 deck completed.
  • Nov 2012 — Main structure completed.
  • Sep 2014 — Section opened to traffic.

Related reading: EE&HL case study: Gilberto Borja Navarrete Viaduct — the tallest pier ever built for a balanced cantilever bridge

The Pattern & The Question

What changes when an early-warning test reports after the whole batch, an illustrative exposure framework, and three questions to put to your own test sequence.

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Sources and further reading

  1. Design teamArribas Mazarracín, D., González Esteban, J. I., Pérez Casas, J. M. and Bernal Sahún, P., “Gilberto Borja Navarrete Viaduct”, Hormigón y Acero 66(275), 2015 (English edition)Source: geometry, pier 4 foundation, sonic test results, grouting, supplementary piles, pile cap, deck completion and opening dates. Spanish edition.
  2. PhotoHighestBridges, Wikimedia CommonsCC BY-SA 3.0.

Source labels describe provenance, not authority. See our editorial methodology.

Marco Torri

Founder and Editor, EE&HL Network · Commercial intelligence for erection engineering & heavy lift

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