Construction activities produce ground vibrations that can affect nearby structures and improvements by affecting the soil that supports the structure and/or by vibrating the structure. Construction activities such as pile driving, blasting, or breaking pavement can produce strong levels of vibration and are commonly cited as the cause of damage to nearby structures and improvements. Vibrations that are smaller in magnitude, such as those induced by traffic, equipment, and machines, may also cause damage under certain circumstances. Damage caused by construction vibrations is commonly architectural (“cosmetic”) and results from non-uniform displacements imparted on the structure or improvement. Vibrations from construction activities can also be strong enough to cause settlement of the soil (“indirect” effect). Damage to existing structures resulting from excessive vibrations can range from cosmetic cracking in the walls to serious cracking that may compromise the structural integrity of the building or improvements.
Exponent engineers use many tools to measure and characterize the source and magnitude of the induced ground vibration and its effects on structures. Key elements in these investigations include establishing the baseline conditions (e.g., prior to planned construction activities), assessing the source of vibrations and the damage caused, analyzing the magnitude and zone of influence of vibrations, and preparing conceptual recommendations for repair, if requested.
Our services include:
- Determination of the nature and extent of damage to structures from vibrations
- Pre-construction surveys of existing buildings and improvements
- Pre-construction review of construction plans and activities
- Monitoring and recording ground vibrations
- Monitoring with geotechnical instrument and equipment, including manometer surveys, tiltmeters, slope inclinometers, strain gauges, piezometers, and extensiometers
- Damage assessment at adjacent properties
- Analysis of ambient ground vibrations
- Analysis of measured vibrations induced by construction activities
- Analysis of level survey data and geotechnical instrumentation
Exponent engineers and scientists have broad experience in investigating damage due to construction vibrations for small and large-scale projects.