Tunneling / TBM in Tempe, AZ

How Tunneling / TBM Works in Tempe

Microtunneling in Tempe begins with shored entry and reception shafts — dewatered and surveyed to city hold points. A steering head mines the face while pipe segments jack behind; slurry handling matches lake-adjacent groundwater. Laser guidance keeps grade for gravity sewer.

Soil & Geology — Maricopa County

Tempe sits on Salt River alluvium and caliche hardpan with Papago foothill granite cobble on east-side shots — lakebed and Rio Salado fill change mud programs block to block.

Most Tempe bores hit caliche crust between 2 and 7 feet, then Salt River alluvium or compacted urban fill depending on distance from the lake bed. Papago fringe and east Tempe shots add decomposed granite cobble that slow penetration without correct tooling. Rio Salado grading can hide old canal structures and debris lenses that potholing catches before pits are sized. Shallow groundwater along Tempe Town Lake and the Salt River bed raises buoyancy risk on long HDPE pulls — we size ream stages for Tempe fill, not a generic suburban template.

Weather & Scheduling

Urban heat island, monsoon outflows from the Salt River bed, and afternoon lightning holds shape Tempe bore schedules — lake-adjacent groundwater and wash runoff are planned into quotes.

Monsoon season from July through September raises lake-adjacent groundwater and can delay entry pits on Rio Salado fill. Spring dust on exposed Papago fringe pads affects cage and fluid handling along Broadway. Summer urban heat slows morning startup on Mill Avenue sites but rarely stops work — we communicate when dry conditions matter for caliche-heavy pits rather than risk frac-outs toward Tempe Town Lake.