Be Grand Reforma

Engagement scope

• Independent peer review of the structural-seismic design under the Performance-Based Seismic Engineering framework
• Verification of the site-specific seismic hazard study and the design ground-motion definition
• Audit of the modal characterisation and the structural model used by the design office
• Cross-check of the time-history response under both code-level and Maximum Considered Earthquake demands
• Comment cycles on the WSP design package and on the geotechnical campaign for the lakebed soil column
• Synthesis report consolidating the peer-review findings for the owner and the regulatory dossier

Why this engagement mattered

Mexico City's central valley is the textbook case for "the ground decides the loss curve." The historical Lake Texcoco was drained centuries ago, but the high-plasticity lacustrine clay it left behind still amplifies long-period seismic waves by up to an order of magnitude. The 1985 magnitude-8.1 Michoacán earthquake — its epicentre 350 km away — destroyed buildings in this clay belt at intensities the surrounding hills barely registered. Thirty-two years later, on the same calendar day, the 2017 magnitude-7.1 Puebla–Morelos event hit the city again. The lakebed was, once more, decisive.

Be Grand Reforma — known on the engineering drawings as Torre La Fragua, after the street it sits on — is a 47-storey, 195 m luxury tower in the Tabacalera neighbourhood, a few blocks from the Monument to Columbus on Paseo de la Reforma. Below the city, the building plunges 26 m through the soft clay into a 7-level basement. Mid-rise structures of 8 to 20 storeys were the casualties of 1985 and 2017 because their natural periods coincided with the lakebed's amplification window. A 195 m tower has a longer period — and a larger mass — and lands on a different part of the same hazard surface. Designing it well is a different problem from designing the dozen buildings around it; underwriting it generically is even harder.

What was actually delivered

Inversiones y Desarrollos Urbanos (IDU), the developer, retained Dynamis to act as the independent peer reviewer of the structural-seismic design. The structural designer of record was the US firm WSP, working under a Performance-Based Seismic Engineering framework — the same family of methodologies (TBI, LATBSDC, ASCE 41) used for tall buildings in Los Angeles, San Francisco and Tokyo. Peer review under this framework is not a code check; it is an independent re-walk of every seismic decision: hazard definition, soil column, modal behaviour, capacity demand, drift control, ductility, redundancy.

Dynamis's peer review covered the full engagement window from late 2017 through 2018 — the months immediately after the September 19, 2017 earthquake had reset every CDMX engineer's prior on what "moderate seismic" means. The deliverable consolidated dozens of comment cycles between the European peer reviewer, the US designer, the Mexican geotechnical office, and the regulator's reviewer. It addressed two things at once: the site-specific seismic hazard for a long-period asset on amplifying clay, and the explicit time-history verification of the structural model under both code-level and Maximum Considered Earthquake demands.

What this means for portfolio risk

For a (re)insurer underwriting tall residential or mixed-use exposure in Mexico City, three observations from this engagement matter more than any single number:

1. Period matters as much as PML. The lakebed amplifies long-period waves. A 195 m tower on Reforma sees a different demand curve than a 12-storey building three blocks away on the same plot — even though a generic vulnerability function reads the same postcode for both. Asset-class drift between "high-rise on lakebed" and "mid-rise on lakebed" is one of the largest, least-modelled drivers of CDMX cat loss.
2. Independent peer review is a loss-side signal. Buildings that pass an explicit, externally-reviewed PBSE process — with documented MCE-level performance — sit on a different damage curve than buildings that meet code minima alone. A vulnerability function calibrated on the average CDMX building stock systematically under-credits this difference.
3. The 2017 event re-priced the ground, not the code. The structural code that bound the design was not the variable — what changed in late 2017 was practitioners' confidence in long-period site response. A peer-review record from that exact window carries information that does not appear anywhere on a coarse hazard map.

From engagement to portfolio indicators

Every project of this calibre — engineered to perform, peer-reviewed against the same standard used in Los Angeles and Tokyo — becomes evidence in the engine that powers Xpectral. The independent verification of a 195 m tower's response under MCE-level demand, on a soil column that already wrote 1985 and 2017 into the loss record, is not an isolated deliverable: it calibrates the hazard model and, more importantly for our roadmap, it informs the engineering-grade fragility curves we are now building for the most exposed asset classes.

Fragility curves today are built on simplified assumptions. Ours are built on 15 years of designing structures that cannot fail. By embedding performance-based seismic design into AI-driven models, we transform fragility from generic to engineering-grade.

— Carlos Caramés Molero, Founder & Partner, Dynamis

That difference does not stay academic. It propagates straight into the indicators (re)insurers actually price on: PML for catastrophe risk capital, AAL for technical premium, EP curves for accumulation control on the Reforma-corridor exposure, SCR for Solvency II capital efficiency. Generic vulnerability functions cannot tell the difference between a code-minimum mid-rise and a peer-reviewed tall tower whose long period is paired with a soil column that amplifies precisely those frequencies. Ours can — because we engineered both.

Sources & references

1. Dynamis project portfolio: dynamisassociates.com
2. Inversiones y Desarrollos Urbanos (IDU), Be Grand Reforma development programme; public corporate communications, 2017–2018.
3. Mexico City building code Reglamento de Construcciones para el Distrito Federal and its post-2017 update; CDMX seismic zoning, lakebed (Zone IIIb).
4. Performance-Based Seismic Engineering frameworks for tall buildings: TBI Guidelines, PEER (2017); LATBSDC (2017); ASCE 41-17.
5. Internal Dynamis peer-review archive — confidential, not public.