1 Concrete Leveling Contractors in Portsmouth, New Hampshire

If you need concrete leveling in Portsmouth, the usual culprits are dense glacial-till mantle with Hollis, Charlton, Paxton, and Woodbridge till-derived sandy loams and fragipans, and frost-susceptible silt-rich till producing aggressive freeze-thaw heave (with Atlantic-coast moderating effect reducing frost depth somewhat). Portsmouth is a city in eastern Rockingham County, southeastern New Hampshire, sitting along Interstate 95, US-1, US-4, NH-1A, and NH-33 about 50 miles east-southeast of Concord on the Atlantic seacoast at the mouth of the Piscataqua River. The Abenaki tribes, largely divided between the Androscoggin, Ko'asek, and Pennacook nations, lived in the area as long as 12,000 years before European settlement; the first European to explore and write about the area was Martin Pring in 1603, and Mason sent a group of colonists who arrived at Odiorne's Point in Rye (near Portsmouth) by a group of fishermen from England under David Thompson in 1623. The west bank of the harbor was settled by European colonists in 1630 and named Strawbery Banke, after the many wild strawberries growing there; Portsmouth was incorporated in 1653 and named to honor its founder, John Mason, who had been a captain of Portsmouth, England. The Piscataqua River is a 12-mile-long tidal river forming the boundary of the U.S. states of New Hampshire and Maine; the last six miles before the sea form Portsmouth Harbor, one of the finest harbors in the northeastern United States, despite a tidal current rated as one of the fastest in North America (with a flood current speed of 12 knots, making it the fastest river on the eastern seaboard of the United States). Strategically well located to trade with both upstream industries and foreign merchants, the port prospered: fishing, lumbering, and shipbuilding were the town's major industries, and the river was the site of the first sawmill in the colonies in 1623. Today Portsmouth (population 21,956 at the 2020 census) is a historic Atlantic seaport, the home of the Portsmouth Naval Shipyard (in Kittery, Maine, but historically tied to Portsmouth), and a major regional service center for the Seacoast tourism economy with significant Strawbery Banke historic-coordination and downtown-historic-district character. Portsmouth sits on the rolling till-mantled bedrock terrain of the Atlantic seacoast, in the Piscataqua River drainage to the Gulf of Maine. Bedrock is principally Silurian-Devonian Berwick Formation metasedimentary rocks (mica schist and quartzite) of the Merrimack Trough, with Devonian Concord-type granite plutonic intrusions of the New Hampshire Plutonic Suite, Silurian-Devonian Eliot Formation phyllite of the Merrimack Trough locally, and Cretaceous-age White Mountain Plutonic Suite intrusions (with the Rye Complex of Ordovician metasedimentary rocks at Odiorne Point). Above bedrock, late Wisconsinan glacial till (a stony sandy loam mantle deposited 14,000 years ago by the retreating Laurentide Ice Sheet) blankets the hillsides, with extensive Presumpscot Formation glaciomarine clay (deposited in the late-glacial DeGeer Sea, when isostatically-depressed land allowed marine inundation up the seacoast lowland; Portsmouth is at the heart of the marine submergence with thick brick-clay deposits historically used for the Seacoast brick industry), glaciofluvial outwash (sand and gravel) along the Piscataqua corridor, glacial-lake-deposited fine sediments in some valley bottoms, Holocene salt-marsh peat in the dense Great Bay and Piscataqua tidal marshes, beach-and-dune sand on the South End and seacoast parcels, historic mill-tailings-and-fill on the dense downtown industrial-corridor parcels, and significant urban-fill on the South End, North End, and downtown harbor-redevelopment parcels (with multiple centuries of harbor-front fill activity). Local soils include Hollis and Charlton complex on the till uplands (the dominant southern New England forest soil; Hollis is shallow-to-bedrock and Charlton is deeper till), Paxton fine sandy loam on the till uplands (with significant fragipan), Woodbridge fine sandy loam on the till uplands (poorly drained over fragipan), Ridgebury fine sandy loam on the till lowlands (very poorly drained), Buxton silt loam on the marine-clay terraces (developed on Presumpscot Formation glaciomarine clay, with significant historical brick-clay extraction), Scantic silt loam on the very-poorly-drained marine-clay parcels, Hinckley loamy sand on the outwash terraces (excessively drained kame-and-esker glaciofluvial), Hooksan loamy sand on the seacoast-dune parcels, Ipswich mucky peat on the salt-marsh flats, Pawcatuck mucky peat on the brackish-tidal salt-marsh flats, Searsport mucky peat on the freshwater wetland flats, Saco silt loam on the alluvial flats, and gravelly alluvium and dredge-fill along the Piscataqua corridor. Between dense glacial-till mantle with Hollis, Charlton, Paxton, and Woodbridge till-derived sandy loams and fragipans, frost-susceptible silt-rich till producing aggressive freeze-thaw heave (with Atlantic-coast moderating effect reducing frost depth somewhat), perched-water cycling on Paxton and Woodbridge fragipan parcels driving subgrade saturation, the documented Buxton-Scantic Presumpscot-Formation glaciomarine clay shrink-swell-and-consolidation subgrade movement on the dense lower-elevation parcels (with multiple centuries of brick-clay extraction in Portsmouth historically), Berwick-Formation and granite shallow-bedrock differential bearing on bedrock-near-surface parcels, glacial erratics producing localized hard spots, the historic 1630-onward Strawbery Banke and downtown Portsmouth waterfront foundations dating to the colonial settlement (with century-and-a-half-old to nearly-four-century-old foundations), Ipswich-Pawcatuck salt-marsh organic peat with extreme compressibility on the dense Great Bay and Piscataqua tidal-marsh parcels (where injection is unsuitable), Hooksan dune-sand parcels on the South End seacoast with mobile-sand subgrade variability, Atlantic-coast salt-air sulfate-and-chloride attack on concrete (with documented marine-environment exposure on the seacoast parcels), the dense Portsmouth Naval Shipyard area waterfront fill and dredge-spoil parcels with documented urban-fill variability, and steady seacoast-and-Boston-corridor commuter, downtown-redevelopment, and dense waterfront-historic cut-and-fill on the recent I-95, US-1, and NH-33 corridor parcels, subgrade behavior is the primary driver of slab movement here.