FOUNDATION FAILURES

Introductory note. Part 1: Investigation of site. Absence of preliminary investigation. 11.1 Underpinning. 11.2 Costly construction. Unsatisfactory preliminary investigation. 12.1 Variation of soil. 12.2 Neglecting ground-water. Incomplete co-operation. 13.1 The effects of surfaces water on soil. Neglect of possibility of soil sliding. 14.1 Sliding soil. Part 2: Unsuitable types of structures and foundations. Unsuitables superstructures. 21.1 Excessive bearing pressure. 21.2 Horizontal forces on foundations. Unsuitable foundations. 22.1 Unbalanced horizontal forces. 22.2 Excessive bearing pressure. 22.3 Excessive safety measures. 22.4 Foundations at different levels. 22.5 Excavations deeper than adjacent foundations. Foundational of different types under the same buildings. 23.1 Different lengths of piles. 23.2 Bearing strata of variable thickness. 23.3 Structures of non-uniform weight. Excessively rigid foundations. 24.1 Unreasonable requirements for a loads. Incomplete assessment of effects of loads. 25.1 Dynamic effects 25.2 Stress superposition. 25.3 Neglecting future loads. Part 3: Defects and failures due to defective execution. Unsuitable methods of dewatering. 31.1 Land-drainage structures. 31.2 Bridges. 31.3 Sinkings a Caissons. 31.4 Differential settlement. Faulty excavation. 32.1 Cofferdams. 32.2 Earth banks. 32.3 Ineffective bracing. Faulty construction. 33.1 Changing the load on tapered piles. 33.2 Unsuitable spacing of piles. 33.3 Piles in wrong position. 33.4 Piles spaced too closely. 33.5Piles of unsuitable length. 33.6 Sliding of a quay wall. 33.7 Upward pressure in silty clay. 33.8 Subsidence during sinking of a caisson. 33.9 Non-uniform compaction of loose soil. Defective workmanship and materials. 34.1 Defective concrete. 34.2 Defective sheet-piling. 34.3 Faulty waterproofing. Part 4: Failures due to external influences. Defects due to ground water. 41.1 Seeping and fluctuation. 41.2 Absence of weep-holes. 41.3 Oscillation of water level. 41.4 Change of use of adjacent land. 41.5 Unexpected saturation. Damage due to floods. 42.1 Scouring due to floods. 42.2 Combined flood and seepage. Changes of water-content of soil and application of additional loads. 43.1 Increased water-content of soil. 43.2 Water-content of soil. 43.3 Precautions to be taken in excavating pits. Landslides. 44.1 Bridge abutments. 44.2 Deterioration of the strength of clay. Effects of frost, changes of temperature, drought and vegetation. 45.1 Frost under basement floor. 45.2 Higher temperatures after construction. 45.3 Effects of drought. 45.4 Effects of roots of tress. Swelling of clay.

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