1. Soil Mechanics

2. Tower of Pisa BASICS Official Name: TORRE PENDENTE DI PISA Function: Bell Tower (Campanile) Original Architect: Bonanno Pisano Years Built: 1173-1350 Height: 55.863 meters (185 feet). 8 stories. Outer Diameter of Base: 15.484 meters Inner Diameter of Base: 7.368 meters Weight: 14,700 metric tons Thickness of Walls at the Base: 8 feet Direction of Lean: 1173-1250 North, 1272-1997 South

3. Latitude: 43.7167 Longitude: 10.3833 Elevation of Piazza : About 6 ft, (2 m) First Construction Stop: 1178 (War with Firenze) Lean obvious: 1178 (3rd Story: 10.6m ) Level - Tower Straightens to North: 5 (About 110 meters) 2nd Construction Stop: 1185 (War with Firenze) Later Construction Stop: 1284 (War with Genoa, Major Sea Battle Defeat)

4. ♦STRATUM

5. Since 1913 - Geodetic measurements Since 1934 - Civil Engineers spirit level Since 1991 - Accurate internal optical system - Automatic system with sensors for the measurement of: 1. wind 2. air temperature 3. solar radiation 4. seismic actions 5. inclinations 6. horizontal point movement 7. dimensional variation in vertical and horizontal sections 8. width of the fissures 9. masonry temperature 10. levels within the stratum The measurements - The measurements every 4 hours - The sensitivity of the length measurements is 1/100mm. -The sensitivity of the inclination measurements is 1/36000°

6. Structural Problems of Inclination The exceptional inclination of the Tower generates a dangerous concentration of vertical compression forces in the lower masonry. The situation is particularly unfavourable in the 1st arcade, where: –The door to the loggia and the passage reduces the resistance of the region; –The interruption of the marble facing induces stress concentrations in the weak masonry filling underneath; –Numerous scaffolding holes reduce the resistance of the region; –Radial tension has already cracked the steps and the ceiling of the spiral staircase.

7. Tower of Huqiu in suzhou Another example is the Huqiu tower in Suzhou, because of tower foundation’s asymmetry settlement sinking, the tower body is tilting to the northeast:

8. Other Examples: - BC Mansion in Hongkong - A Mansion in South America - Transcona Grain Elevation History: 1773, C A Coulomb (France) 1869, W J M Rankine (UK) 1885, J Boussinesq (France) 1922, W Fellenius (Sweden) 1925, K Terzaghi 1936, 1 st (ICSMFE) International Conference on Soil Mechanics and Foundation Engineering

10. Main Contents: - Soil Physical Characteristics and Classification - Permeability and Stress in Soil - Deformation, Consolidation & Settlement - Shear Strength Theory - Earth Pressure & Retaining Walls’ Design - Slope Stability - Bearing Capability

11. References 1 R F Craig, Soil Mechanics 2 G.E. Barnes Soil Mechanics Principles and PracticeG.E. Barnes 3 Braja M Das, Advanced Soil Mechanics 4 梁钟琪，土力学及路基 （铁道出版社） 5 陈希哲， 土力学（清华出版社） 6 四院校合编，地基与基础 （建工出版社） 7 胡中雄，土力学与环境岩土工程 （同济出版社）