Some Engineering Problems Of The Panama Canal In Their Relation To Geology And Topography

4 CONTENTS. Page. Rock material used in canal construction..................................... 35 Different types of rock material used.................................... 35 Sources of material...................................................... 36 Ancon Hill........................................................... 36 Porto Bello quarry................................................... 36 Unsatisfactory hard rock deposits.................................... 36 Sosa Hill............................................................ 37 Chagres River gravel................................................. 37 Unsatisfactory gravel in Canal Zone streams.............................. 37 Stability of canal foundations............................................... 38 Geologic structure of foundation rocks................................... 38 General considerations............................................... 38 Foundations of the Gatun dam and locks............................... 39 Position of Gatun Lake........................................... 39 Three great questions involved in dam............................ 40 Difficulties with hydraulic filling material..................... 42 Some details of lock construction................................ 42 Description of Gatun-Lock foundations............................ 43 Influence of the old Chagres River channel....................... 44 Foundation of the Pedro Miguel Locks................................. 45 Description of lock sites........................................ 45 Foundation of the Corozal locks and dam.............................. 46 Foundation of the new administration building, Balboa................ 47 Slides....................................................................... 48 Analysis of conditions leading to slides................................. 49 Influence of crushing and tensile strength of the rocks involved... 50 Influence of physical and chemical character of rock units........... 51 Effect of ground water............................................... 52 Effect of earth tremors.............................................. 53 Effect of other factors.............................................. 54 Types of slides or deformations in Culebra Cut........................... 54 Structural breaks and deformations................................... 54 General description.............................................. 54 Causes........................................................... 54 Remedies......................................................... 56 Slides in Gold Hill and Contractors Hill not likely.............. 56 Yardage of the chief slides caused by structural breaks.......... 57 Previous statement regarding stability of highest parts of Culebra Cut.............................................................. 57 Probable limits of sliding ground................................ 59 Summary.......................................................... 59 Normal or gravity slides............................................. GO Fault zone slides.................................................... 61 Slides due to erosion................................................ 63 Remedies......................................................... 63 Slides due to wash, of steamers...................................... 63 Some slides outsiae the Canal Zone...................,................... 64 Slide near Portland, Oreg............................................ 64 Slide on slopes of Des Moines River, Iowa............................ 65 Slide in British Columbia............................................ 65