Checklist for construction supervision and performance monitoring
The list that follows contains the more important items that should be considered when supervising construction or monitoring the performance of the completed structure. The importance of the items will vary from project to project. The list is not exhaustive. Items that refer to specific aspects of geotechnical engineering or to specific types of works have been reported in the Sections of this standard.
J.2 Construction supervision
J.2.1 General items to be checked
(1) Verification of ground conditions and of the location and general lay-out of the structure.
(2) Ground-water flow and pore-water pressure regime; effects of dewatering operations on ground-water table; effectiveness of measures taken to control seepage inflow; internal erosion processes and piping; chemical composition of ground-water; corrosion potential.
(3) Movements, yielding, stability of excavation walls and base; temporary support systems; effects on nearby buildings and utilities; measurement of soil pressures on retaining structures; measurement of pore-water pressure variations resulting from excavation or loading.
(4) Safety of workmen with due consideration of geotechnical limit states.
J.2.2 Water flow and pore-water pressures
(1) Adequacy of systems to ensure control of pore-water pressures in all aquifers where excess pressure could affect stability of slopes or base of excavation, including artesian pressures in an aquifer beneath the excavation; disposal of water from dewatering systems; depression of ground-water table throughout entire excavation to prevent boiling or quick conditions, piping and disturbance of formation by construction equipment; diversion and removal of rainfall or other surface water.
(2) Efficient and effective operation of dewatering systems throughout the entire construction period, considering encrusting of well screens, silting of wells or sumps; wear in pumps; clogging of pumps.
(3) Control of dewatering to avoid disturbance of adjoining structures or areas; observations of piezometric levels; effectiveness, operation and maintenance of water recharge systems, if installed.
(4) Settlement of adjoining structures or areas.
(5) Effectiveness of sub-horizontal borehole drains.
J.3 Performance monitoring
(1) Settlement at established time intervals of buildings and other structures including those due to effects of vibrations on metastable soils.
(2) Lateral displacement and distortions, especially those related to fills and stockpiles; soil supported structures, such as buildings or large tanks; deep trenches.
(3) Piezometric levels under buildings or in adjoining areas, especially if deep drainage or permanent dewatering systems are installed or if deep basements are constructed.
(4) Deflection or displacement of retaining structures considering: normal backfill loadings; effects of stockpiles; fills or other surface loadings; water pressures.
(5) Flow measurements from drains.
(6) Special problems:
- High temperature structures such as boilers, hot ducts: desiccation of clay or silt soils; monitoring of temperatures; movements;
- Low temperature structures, such as cryogenic installations or refrigerated areas: monitoring of temperature; ground freezing; frost heave; effects of subsequent thawing.
(7) Water tightness.
(8) Vibration measurements.