1 General Provisions
1.0.1 This code is formulated with a view to unifying the technical requirements for the design and construction of soil foundation and foundation treatment of port engineering, performing effective control on the engineering quality and satisfying the requirements of safety and reliability, advanced technology, economy and rationality as well as durable application.
1.0.2 This code is applicable to the design and construction for soil foundation and foundation treatment of port engineering structures. The soil foundation and foundation treatment of hydraulic structure for shipbuilding and repairing yards as well as navigation structure may refer to this code. This code is not applicable to such special soil foundations as collapsible soil, red clay, frozen soil, salty soil and expansive soil foundations.
1.0.3 The design and construction of soil foundation and foundation treatment shall adhere to the principles of adapting to local conditions, utilizing materials nearby, protecting environment and saving resources; and the structure type as well as material and construction conditions shall be taken into full consideration in combination with the geotechnical engineering investigation data.
1.0.4 The design and construction for soil foundation of port engineering structures shall not only meet the requirements of this code, but also comply with those in the current relevant ones of the nation.
2 Terms
2.0.1 Standard value for physical and mechanical index of soil
A tantile of probability distribution for physical and mechanical index of soil, taking 50% in this code.
2.0.2 Strain consolidation
The ratio of settlement at certain moment and the final settlement when the saturated soil layer is under some loads, expressed by percentage (%).
2.0.3 Stress consolidation
The ratio of excess pore water pressure dissipation at certain moment and the initial excess pore water pressure when the saturated soil layer is under some loads, expressed by percentage (%).
2.0.4 Weight
Gravity density or volume weight, namely gravity received by rock-soil material of unit volume.
2.0.5 Specific gravity of soil particle
The ratio of the weight of soil particle weight to the weight of 4℃ distilled water of the same volume.
2.0.6 Inclined angle of resultant force
An included angle on the calculating face between the resultant direction and the vertical direction.
2.0.7 Gradient of resultant force
An included angle on the calculating face between the horizontal resultant force and the vertical resultant force.
2.0.8 Dangerous sliding surface
A sliding surface to minimize the partial safety factor for resistance where the soil slope and foundation stabilization is calculated.
2.0.9 Pre-consolidation pressure
The maximum effective vertical pressure on soil mass throughout the geologic history.
2.0.10 Over-consolidation ratio
The ratio of pre-consolidation pressure on soil mass and the effective overburden pressure on existing soil layer.
2.0.11 Under-consolidated soil
Unconsolidated soil under deadweight pressure.
2.0.12 Soft soil
Fine grained soil whose natural void ratio is greater than or equal to 1.0 and whose natural water content is greater than the liquid limit, formed in sedimentary environments such as littoral facies, lagoon facies, delta facies as well as river and lake facies.
2.0.13 Ultra-soft soil
Soft soil whose vane shear strength is less than or equal to 5kPa.
2.0.14 Sensitivity
The ratio of undrained shear strengths of undisturbed soil and remoulded soil.
2.0.15 Total stress method
A method where only total stress is considered (the pore water pressure is ignored) and the total stress strength index is adopted to analyze the soil slope and foundation stabilization.
2.0.16 Effective stress method
A method where the influence of pore water pressure is considered to calculate the slide resistance moment and sliding moment and the effective shear stress index of soil is adopted to analyze the soil slope and foundation stabilization.
2.0.17 Foundation treatment
A method to treat soil foundation manually so as to improve the bearing capacity and stability of foundation and change its deformability or permeability.
2.0.18 Composite foundation
A soil foundation whose partial soil mass is strengthened or replaced by reinforcement and whose loads are shared by reinforcement and surrounding foundation soil.
2.0.19 Vacuum preloading method
A method to subject soil mass to drainage consolidation and strengthen soft soil foundation through vacuum pressure or combined vacuum stack-loading pressure.
2.0.20 Offshore in-depth cement mixing method
A method to strengthen soil foundation through the hydration of cement and its chemical reaction with soil particle after injecting prepared cement paste and other materials into underwater soil foundation with special underwater in-depth agitator and forcibly mix them uniformly with foundation soil on site to form mixed soil.
3 Basic Requirements
3.0.1 The design and construction of soil foundation and foundation treatment shall consider the variability of foundation soil to divide the soil layer unit accurately. For thick soil layer, sublayer should be divided; for soil layer with great variability, the cause of variability shall be analyzed; for soil layer difficult to take samples, site test shall be carried out. In particular, the factors which have great influence on the structure stability shall be found out, such as soft interlayer, unfavorable structural plane of rock mass, karst, underground water condition, landslide mass, old buried river course, old gully, gradient of river bed and change in gradient of side slope due to scouring-and-filling at different seasons.
3.0.2 The statistics of rock-soil physical and mechanical index and other basic variable parameters shall be zoned according to their representativeness as well as the lamination of different geologic units; moreover, it shall meet the relevant requirements of Appendix A. There shall at least 6 statistical test samples for the rock-soil test index tested indoor and on site for each rock-soil mass unit.
3.0.3 Where reliability index need be calculated, the sampling requirements and the statistical parameters for rock-soil physical and mechanical index and other basic variables shall be considered according to random field, and shall meet the relevant requirements of Appendix A.
3.0.4 The soft clay foundation under wave force and other reciprocating loads shall consider when there is any softening and strength reduction; if necessary, the strength index shall be determined through experimental study.
3.0.5 The soil foundation shall be inspected and monitored during its construction and service period; the items and methods of inspection and monitoring shall meet the relevant requirements of the current professional standard "Technical Specification of Prototype Observation for Water Transport Hydro-structure" (JTJ 218).
1 General Provisions
2 Terms
3 Basic Requirements
4 Rock-soil Classification
4.1 Rock Classification
4.2 Soil Classification
5 Foundation Bearing Capacity
5.1 General
5.2 Stress on Calculating Face
5.3 Calculation of Foundation Bearing Capacity
5.4 Measures for Maintaining and Improving Foundation Bearing Capacity
6 Soil Slope and Soil Foundation Stabilization
6.1 General
6.2 Shear Strength Index
6.3 Soil Slope and Soil Foundation Stabilization Calculation
6.4 Partial Safety Factor for Resistance
6.5 Assurance Measures for Soil Slope and Base Stabilization
7 Foundation Settlement
7.1 General
7.2 Final Settlement Calculation of the Foundation
7.3 Final Settlement Estimation for the Foundation
7.4 Adaption and Reducing Measures for Foundation Settlement and Differential Settlement
8 Foundation Treatment
8.1 General
8.2 Sand Cushion Replacement
8.3 Preloading by Stacking
8.4 Light Vacuum Well Point
8.5 Dynamic Compaction
8.6 Vibro-replacement
8.7 Vibro-compaction
Appendix A Approximate Methods for Determining the Probability Distribution and Statistical Parameters of the Rock-soil Basic Variables
Appendix B Weathering Degree Classification of Rock and Rock Mass
Appendix C Classification of Rock Mass According to Structure Type
Appendix D Reference Values of Physical and Mechanical Indexes for Different Weathering Degrees of Granite
Appendix E Formation Type and Engineering Geology Features of Common Soil
Appendix F Field Identification Method of Gravelly Soil Compactness
Appendix G Foundation Bearing Capacity Determined by Table Loop-up
Appendix H Foundation Bearing Capacity Factor Table
Appendix J Method of Vane Shear Strength Regression for Calculating Shear Strength Index
Appendix K Correction of the Partial Safety Factor for Resistance of Soil Slope Stabilization with a Consideration of Side Friction resistance
Appendix L Diagram of the Foundation Vertical Additional Stress Factor
Appendix M Method of Estimating the Consolidation Factor According to Measured Settlement Process Line by Stage Loading
Appendix N Computational Table of Average Stress Consolidation
Appendix P Explanation of Wording in This Code
Additional Explanation List of Chief Development Department, Participating Organizations, Chief Drafting Staffs, Chief Proofing Staffs and Administrative Personnel for This Code
