Micropiling in Urban Infrastructure: Advantages, Experience and Challenges-Paper

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The paper examines the use of self-drilling micropiles to meet the demands of urban infrastructure development, where construction and upgrades must often be completed quickly, in confined spaces, and with minimal disruption. These micropiles use hollow, threaded steel bars installed by rotary-percussive drilling while grout is injected continuously, creating a strong bond with surrounding soil.<br /><br />Case studies from Colombia, Italy, Bolivia, and India illustrate applications across public services, transportation, telecommunications, and heritage conservation. Projects included reinforcing hospital and school foundations, supporting cable-car towers above an existing canal, constructing foundations for mobile-phone towers, and underpinning a historic city hall. Micropiles were installed inside and outside existing buildings, including in spaces with low ceilings, and in varied ground conditions.<br /><br />The reported benefits include compact, flexible equipment; efficient installation; low vibration and reduced noise and dust; suitability for restricted-access sites; and smaller foundation footprints and reduced use of concrete and reinforcing steel. These qualities can help maintain the operation of existing facilities during construction and support both new infrastructure and seismic or structural retrofits.<br /><br />The paper concludes that micropiles are a versatile, cost-effective option for urban projects, including the preservation of culturally significant buildings. However, permanent applications require particular attention to long-term performance: steel elements must be adequately protected from corrosion, including through effective grout encapsulation, so that design capacity is maintained throughout the structure’s intended service life.

Keywords

self-drilling micropiles

urban infrastructure

micropile foundations

rotary-percussive drilling

grout injection

restricted-access construction

seismic retrofitting

heritage conservation

corrosion protection

foundation reinforcement