Dewatering and Groundwater Control - index
Chapter 1: Introduction - ufc_3_220_050010
Permanent groundwater control
Figure 1-2. Permanent groundwater control system
Chapter: Methods for Dewatering,Pressure Relief, and Seepage Cutoff
Figure 2-1. Dewatering open excavation by ditch and sump
Figure 2-2. Self-jetting wellpoint
Deep-well systems - ufc_3_220_050016
Vertical sand drains - ufc_3_220_050017
Figure 2-6. Jet-eductor wellpoint system for dewatering a shaft
Slurry walls
Selection of dewatering system
Figure 2-10. Electra-osmotic wellpoint system for stabilizing an excavation slope
Geologic and soil conditions
Table 2-1. Summary of Groundwater Control Methods
Depth of groundwater lowering
Figure 2-12. Dewatering Systems Applicable to Different Soils
Figure 2-13. Recharge of groundwater toprevent settlement of a building as a result of dewatering operations
Chapter 3: Geologic,Soil ,and Groundwater Investigations
Figure 3-1. Geologic profile developed from geophysical explorations
Figure 3-2. Permeameters: (a) constant head and(b) falling head
Groundwater characteristics
Table 3-2. Specific Yield of Water-Bearing Deposits in Sacramento Valley, California
Field pumping tests
Figure 3-5. Formulas for determiningpermeability from field failing head tests
Surface water - ufc_3_220_050034
Chapter 4: Design of Dewatering, Pressure Relief, and Groundwater Control Systems
Figure 4-1. Flow and head for fully penetrating line slot; single-line source; artesian, gravity, and combined flows
Figure 4-2. Height of free discharge surface hs; gravity flow
Figure 4-3. Flow and head for partially penetrating line slot; single-line source; artesian, gravity, and combined flows
Figure 4-4. Flow and head for fully and partially penetrating line slot; two-line source; artesian and gravity flows
Figure 4-5. Flow and head (midway) for twopartially penetrating slots; two-line source; artesian and gravity flows
Figure 4-6. Flow and head for fully and partially penetrating circular slots; circular source; artesian flow
Figure 4-7. Head at Center of Fully and Penetrating Circular Slots:Circular Source: Artesian Flow
Figure 4-8. Flow and drawdown at slot for fully and partially penetrating rectangular slots; circular source; artesian flow
Figure 4-9. Head within a partially penetrating rectangular slot; circular source; artesian flow
Figure 4-10. Flow and drawdown for fully and partially penetrating single wells; circular source; artesian flow
Figure 4-11. Flow and drawdown for fully and partially penetrating single wells; circular source; gravity flow
Figure 4-12. Flow and drawdown for fully penetrating single well; circular source; combined artesian and gravity flows
Figure 4-13. Flow and drawdown for fully penetrating multiple wells; circular source; artesian and gravity flows
Figure 4-14. Drawdown factors for fully penetrating circular, rectangular, and two-line well arrays; circular source; artesian and gravity flows
Figure 4-15. Flow and drawdown for fully penetrating circular well arrays; circular source; artesian flow
Figure 4-16. Flow and drawdown for partially penetrating circular and rectangular well arrays; circular source; artesian flow
Figure 4-17. Flow and drawdown for fully penetrating single well; line source; artesian and gravity flows
Figure 4-18. Flow and drawdown for fully penetrating multiple wells; line source; artesian and gravity flows
Figure 4-19. Drawdown factors for fully penetrating circular, line, two-line, and rectangular well arrays; line source; artesian and gravity flows
Figure 4-20. Flow and drawdown for fully penetrating infinite line of wells; line source; artesian flow
Figure 4-21. Flow and drawdown for fully and partially penetrating infinite line of wells; line source; artesian flow
Figure 4-22. Flow and drawdown for fully penetrating infinite line of wells; line source; gravity flow
Figure 4-23. Approximate radius of influence R
Table 4-1. Index to Figures for Flow, Head, or drawdown Equations for Given Corrections
Figure 4-24. Hydraulic Head Loss in a Well
Figure 4-25. Hydraulic Head Loss in Various Wellpoints
Circular and rectangular slots
Flow-net analyses
Figure 4-26. Shape factors for wells of various penetrations centered inside a circular source
Figure 4-27. Flow and drawdown to slots computed from flow nets
Figure 4-28. Flow and drawdown to wells computed from flow-net analyses
Figure 4-29. Diagrammatic layout of electrical analogy model
Wellpoints, wells, and filters
Figure 4-30. Typical Design of a Filter for a Well or Wellpoint
Pumps, headers, and discharge pipes
Figure 4-33. Characteristics of 6-inch jet pump
Figure 4-34. Deep-well turbine pump
Table 4-2. Capacity of Various Size Submersible and Deep- Well Turbine Pumps
Factors of safety
Dewatering systems
Dewatering open excavations
Vacuum wellpoint system
Deep-well systems - ufc_3_220_050078
Cement and chemical grout curtain
Figure 4-36. Flow beneath a partially penetrating cutoff wall
Dewatering shafts and tunnels
Freezing
Control of surface water
Control of surface water -Cont.
Chapter 5: Installation of Dewatering and Groundwater Control Systems
Wellpoint systems
Figure 5-2. Self-jetting wellpoint
Figure 5-3. Characteristic parts of a wellpoint pump
Vertical sand drains - ufc_3_220_050089
Piezometers - ufc_3_220_050090
Hollow-stem auger method
Development and testing - ufc_3_220_050092
Chapter 6: Operation and Performance Control
Control and evaluation of performance
Operational records
Chapter 7: Contract Specifications
Data to be included in specifications
Measurement and payment
Appendix B: Notations
Appendix B: Notations -Cont. - ufc_3_220_050101
Appendix B: Notations -Cont. - ufc_3_220_050102
Appendix B: Notations -Cont. - ufc_3_220_050103
Appendix C: Field Pumping Tests
Figure C-2. Layout of piezometers for a pumping test
Figure C-3. Section of well and piezometers for a pumping test with gravity flow near well
Figure C-4. Coefficient of permeability kh of various strata determined from a pumping test and flow measurements in the well screen
Equilibrium pumping test
Figure C-6. Drawdown in an observation well versus pumping time (semilog scale)
Nonequilibrium pumping test
Tables C-1. Values of W(u) jor Values of U
Figure C-8. Method 1 (Superposition) for solution of the nonequilibrium equation
Figure C-9. Method 2 for solution of the nonequilibrium equation
Figure C-11. Time-drawdown curves for various conditions of recharge
Figure C-12. Drawdown versus elapsed pumping time for a step-drawdown test
Recovery test
Figure C-16. Typical drawdown and recovery curves for a well pumped and then allowed to rebound
Figure C-18. Displacement of residual drawdown curve when aquifer conditions vary from theoretical conditions
Appendix D: Examples of Design of Dewatering and Pressure Relief Systems
Figure D-1. Open excavation; two-stage wellpoint system; gravity flow
Figure D-2. Open excavation; deep wells; gravity flow
Figure D-3. Open excavation; artesian flow; pressure relief design by flow net
Figure D-4. Open excavation; combined deep-well and wellpoint system; gravity flow
Figure D-5. Open excavation; pressure relief combined with sand drains; artesian and gravity flows
Figure D-6. Trench excavation; pressure relief by wellpoints; artesian flow
Figure D-7. Rectangular excavation; pressure relief by deep wells; artesian flow
Figure D-8. Shaft excavation; artesian and gravity flows through stratified foundation; deep-well vacuum system
Figure D-9. Tunnel dewatering; gravity flows; deep-well system
Figure D-10. Sump and pump capacity for surface runoff to an excavation
Appendix E: Transformation of Anisotropic Soil Conditions to Isotropic Soil Conditions
Appendix F: Well and Total Discharge Measurements
Figure F-5. Pipe cap orifice chart
Approximate measurement methods
Figure F-7. Effective area factor for partially filled pipe
Figure F-10. Formulas for computing flow over various types of weirs
Table F-2: Dimensions and Capacities,Parshall Flumes
Appendix G: Examples of Detailed Dewatering Specifications
Control of water
Maintaining excavation in dewatered condition - ufc_3_220_050139
Specifications - ufc_3_220_050140
Jet-eductor wellpoint system
Pressure relief wells and pumps
Piezometers - ufc_3_220_050143
Compliance with specifications and drawings
Design of dewatering systems
Testing dewatering system
Surface water control
Installation of wells
Placement of sand filter
Pumping test on each well
Equipment and materials
Operation and repair or replacement
Pumping test on the dewatering systems
Installation of well screen and filter sand
Jet-eductor pumps and header pipe
Piezometers - ufc_3_220_050156
Development and testing - ufc_3_220_050157
Dewatering system flow
Standby turbine pumps
Maintaining excavation in dewatered condition - ufc_3_220_050160
Chapter 1: Introduction - ufc_3_220_050010
Permanent groundwater control
Figure 1-2. Permanent groundwater control system
Chapter: Methods for Dewatering,Pressure Relief, and Seepage Cutoff
Figure 2-1. Dewatering open excavation by ditch and sump
Figure 2-2. Self-jetting wellpoint
Deep-well systems - ufc_3_220_050016
Vertical sand drains - ufc_3_220_050017
Figure 2-6. Jet-eductor wellpoint system for dewatering a shaft
Slurry walls
Selection of dewatering system
Figure 2-10. Electra-osmotic wellpoint system for stabilizing an excavation slope
Geologic and soil conditions
Table 2-1. Summary of Groundwater Control Methods
Depth of groundwater lowering
Figure 2-12. Dewatering Systems Applicable to Different Soils
Figure 2-13. Recharge of groundwater toprevent settlement of a building as a result of dewatering operations
Chapter 3: Geologic,Soil ,and Groundwater Investigations
Figure 3-1. Geologic profile developed from geophysical explorations
Figure 3-2. Permeameters: (a) constant head and(b) falling head
Groundwater characteristics
Table 3-2. Specific Yield of Water-Bearing Deposits in Sacramento Valley, California
Field pumping tests
Figure 3-5. Formulas for determiningpermeability from field failing head tests
Surface water - ufc_3_220_050034
Chapter 4: Design of Dewatering, Pressure Relief, and Groundwater Control Systems
Figure 4-1. Flow and head for fully penetrating line slot; single-line source; artesian, gravity, and combined flows
Figure 4-2. Height of free discharge surface hs; gravity flow
Figure 4-3. Flow and head for partially penetrating line slot; single-line source; artesian, gravity, and combined flows
Figure 4-4. Flow and head for fully and partially penetrating line slot; two-line source; artesian and gravity flows
Figure 4-5. Flow and head (midway) for twopartially penetrating slots; two-line source; artesian and gravity flows
Figure 4-6. Flow and head for fully and partially penetrating circular slots; circular source; artesian flow
Figure 4-7. Head at Center of Fully and Penetrating Circular Slots:Circular Source: Artesian Flow
Figure 4-8. Flow and drawdown at slot for fully and partially penetrating rectangular slots; circular source; artesian flow
Figure 4-9. Head within a partially penetrating rectangular slot; circular source; artesian flow
Figure 4-10. Flow and drawdown for fully and partially penetrating single wells; circular source; artesian flow
Figure 4-11. Flow and drawdown for fully and partially penetrating single wells; circular source; gravity flow
Figure 4-12. Flow and drawdown for fully penetrating single well; circular source; combined artesian and gravity flows
Figure 4-13. Flow and drawdown for fully penetrating multiple wells; circular source; artesian and gravity flows
Figure 4-14. Drawdown factors for fully penetrating circular, rectangular, and two-line well arrays; circular source; artesian and gravity flows
Figure 4-15. Flow and drawdown for fully penetrating circular well arrays; circular source; artesian flow
Figure 4-16. Flow and drawdown for partially penetrating circular and rectangular well arrays; circular source; artesian flow
Figure 4-17. Flow and drawdown for fully penetrating single well; line source; artesian and gravity flows
Figure 4-18. Flow and drawdown for fully penetrating multiple wells; line source; artesian and gravity flows
Figure 4-19. Drawdown factors for fully penetrating circular, line, two-line, and rectangular well arrays; line source; artesian and gravity flows
Figure 4-20. Flow and drawdown for fully penetrating infinite line of wells; line source; artesian flow
Figure 4-21. Flow and drawdown for fully and partially penetrating infinite line of wells; line source; artesian flow
Figure 4-22. Flow and drawdown for fully penetrating infinite line of wells; line source; gravity flow
Figure 4-23. Approximate radius of influence R
Table 4-1. Index to Figures for Flow, Head, or drawdown Equations for Given Corrections
Figure 4-24. Hydraulic Head Loss in a Well
Figure 4-25. Hydraulic Head Loss in Various Wellpoints
Circular and rectangular slots
Flow-net analyses
Figure 4-26. Shape factors for wells of various penetrations centered inside a circular source
Figure 4-27. Flow and drawdown to slots computed from flow nets
Figure 4-28. Flow and drawdown to wells computed from flow-net analyses
Figure 4-29. Diagrammatic layout of electrical analogy model
Wellpoints, wells, and filters
Figure 4-30. Typical Design of a Filter for a Well or Wellpoint
Pumps, headers, and discharge pipes
Figure 4-33. Characteristics of 6-inch jet pump
Figure 4-34. Deep-well turbine pump
Table 4-2. Capacity of Various Size Submersible and Deep- Well Turbine Pumps
Factors of safety
Dewatering systems
Dewatering open excavations
Vacuum wellpoint system
Deep-well systems - ufc_3_220_050078
Cement and chemical grout curtain
Figure 4-36. Flow beneath a partially penetrating cutoff wall
Dewatering shafts and tunnels
Freezing
Control of surface water
Control of surface water -Cont.
Chapter 5: Installation of Dewatering and Groundwater Control Systems
Wellpoint systems
Figure 5-2. Self-jetting wellpoint
Figure 5-3. Characteristic parts of a wellpoint pump
Vertical sand drains - ufc_3_220_050089
Piezometers - ufc_3_220_050090
Hollow-stem auger method
Development and testing - ufc_3_220_050092
Chapter 6: Operation and Performance Control
Control and evaluation of performance
Operational records
Chapter 7: Contract Specifications
Data to be included in specifications
Measurement and payment
Appendix B: Notations
Appendix B: Notations -Cont. - ufc_3_220_050101
Appendix B: Notations -Cont. - ufc_3_220_050102
Appendix B: Notations -Cont. - ufc_3_220_050103
Appendix C: Field Pumping Tests
Figure C-2. Layout of piezometers for a pumping test
Figure C-3. Section of well and piezometers for a pumping test with gravity flow near well
Figure C-4. Coefficient of permeability kh of various strata determined from a pumping test and flow measurements in the well screen
Equilibrium pumping test
Figure C-6. Drawdown in an observation well versus pumping time (semilog scale)
Nonequilibrium pumping test
Tables C-1. Values of W(u) jor Values of U
Figure C-8. Method 1 (Superposition) for solution of the nonequilibrium equation
Figure C-9. Method 2 for solution of the nonequilibrium equation
Figure C-11. Time-drawdown curves for various conditions of recharge
Figure C-12. Drawdown versus elapsed pumping time for a step-drawdown test
Recovery test
Figure C-16. Typical drawdown and recovery curves for a well pumped and then allowed to rebound
Figure C-18. Displacement of residual drawdown curve when aquifer conditions vary from theoretical conditions
Appendix D: Examples of Design of Dewatering and Pressure Relief Systems
Figure D-1. Open excavation; two-stage wellpoint system; gravity flow
Figure D-2. Open excavation; deep wells; gravity flow
Figure D-3. Open excavation; artesian flow; pressure relief design by flow net
Figure D-4. Open excavation; combined deep-well and wellpoint system; gravity flow
Figure D-5. Open excavation; pressure relief combined with sand drains; artesian and gravity flows
Figure D-6. Trench excavation; pressure relief by wellpoints; artesian flow
Figure D-7. Rectangular excavation; pressure relief by deep wells; artesian flow
Figure D-8. Shaft excavation; artesian and gravity flows through stratified foundation; deep-well vacuum system
Figure D-9. Tunnel dewatering; gravity flows; deep-well system
Figure D-10. Sump and pump capacity for surface runoff to an excavation
Appendix E: Transformation of Anisotropic Soil Conditions to Isotropic Soil Conditions
Appendix F: Well and Total Discharge Measurements
Figure F-5. Pipe cap orifice chart
Approximate measurement methods
Figure F-7. Effective area factor for partially filled pipe
Figure F-10. Formulas for computing flow over various types of weirs
Table F-2: Dimensions and Capacities,Parshall Flumes
Appendix G: Examples of Detailed Dewatering Specifications
Control of water
Maintaining excavation in dewatered condition - ufc_3_220_050139
Specifications - ufc_3_220_050140
Jet-eductor wellpoint system
Pressure relief wells and pumps
Piezometers - ufc_3_220_050143
Compliance with specifications and drawings
Design of dewatering systems
Testing dewatering system
Surface water control
Installation of wells
Placement of sand filter
Pumping test on each well
Equipment and materials
Operation and repair or replacement
Pumping test on the dewatering systems
Installation of well screen and filter sand
Jet-eductor pumps and header pipe
Piezometers - ufc_3_220_050156
Development and testing - ufc_3_220_050157
Dewatering system flow
Standby turbine pumps
Maintaining excavation in dewatered condition - ufc_3_220_050160
