When designing a flexible pavement in Fullerton, we always start with the Caltrans and AASHTO guidelines, but the real challenge is the local subsurface. Fullerton sits on the eastern edge of the Los Angeles Basin, where alluvial fans from the San Gabriel Mountains mix with older terrace deposits. That means soil profiles can shift from silty sands to stiff clays within a few hundred feet. Our team runs a full set of laboratory tests on every project, including moisture-density relations per ASTM D698 and CBR tests to estimate subgrade strength. Before we even select a pavement layer thickness, we cross-check the data with a subrasante vial evaluation to confirm the bearing capacity under soaked conditions. That step alone avoids a lot of premature cracking.
In Fullerton, the alluvial subgrade can shift from silty sand to stiff clay in a few hundred feet, making layer-by-layer characterization critical for pavement longevity.
Methodology and scope
- Site investigation with test pits and SPT borings to characterize the soil profile
- Laboratory compaction curves at 95% and 100% Proctor density
- Resilient modulus testing for the subgrade and base materials
Local considerations
Fullerton gets about 14 inches of rain per year, but most of it falls between December and March. That concentrated rainfall can saturate the subgrade quickly, especially in areas with poor drainage. If the pavement design doesn't account for the rise in pore pressure, the base layer loses stiffness and the asphalt cracks under truck loads. We also deal with seismic risk from the Whittier Fault zone, which runs north of the city. A moderate earthquake can cause differential settlement in the pavement if the subgrade liquefies. That's why we recommend a respuesta sismica analysis for any flexible pavement design near fault traces or in areas with loose granular soils.
Applicable standards
AASHTO Guide for Design of Pavement Structures (1993), ASTM D1883 (CBR Test), ASTM D698 (Standard Proctor), California Test 301 (Compaction Control)
Associated technical services
Subgrade Investigation
We drill test pits and SPT borings across the site to classify soils per ASTM D2487, measure moisture content, and collect undisturbed samples for resilient modulus testing.
Material Characterization
Full suite of lab tests: sieve analysis, Atterberg limits, compaction curves, and CBR on soaked specimens. All results are reported with the AASHTO layer coefficients.
Pavement Thickness Design
Using AASHTO 1993 methodology, we calculate the required thickness of asphalt concrete, base, and subbase layers based on the design ESALs and subgrade Mr.
Typical parameters
Frequently asked questions
What is the difference between flexible and rigid pavement design?
Flexible pavement relies on a layered structure that distributes loads through the asphalt surface, base, and subgrade. Rigid pavement uses a concrete slab that acts as the primary load-bearing element. In Fullerton, flexible pavement is more common for residential streets and secondary roads because it adapts better to the variable subgrade conditions.
How much does a flexible pavement design study cost in Fullerton?
The cost ranges between US$1,670 and US$4,530 depending on the number of borings, laboratory tests, and the complexity of the traffic analysis. We provide a detailed quote after reviewing the site plan and project scope.
What soil tests are required for flexible pavement design?
The core tests include moisture-density relations (ASTM D698), CBR (ASTM D1883), sieve analysis (ASTM D6913), and Atterberg limits (ASTM D4318). For higher traffic loads, we also run resilient modulus testing per AASHTO T-307.
How does the Whittier Fault affect pavement design in Fullerton?
The Whittier Fault zone can generate ground shaking that loosens unconsolidated soils, leading to differential settlement. In areas within 0.5 miles of the fault trace, we incorporate a thicker base layer and geogrid reinforcement to reduce cracking risk during seismic events.