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This code is prepared under the commission of the Airport Department of Civil Aviation Administration of China for the purpose of meeting the needs of construction and development of civil airports, and unifying the technical standards for geotechnical engineering design for civil airports. After repeated discussions and modifications, this code was submitted for approval by the drafting team, through extensive investigation, careful summarization and assimilation of the design results and construction practice of geotechnical engineering design for civil airport in China for twenty years, reference to relevant domestic and international technical specifications and data during drafting, extensive solicitation of opinions and multiple expert review.
The main technical contents of this code are divided into 9 clauses: 1. General provisions; 2. Terms and symbols; 3. Basic requirements; 4. Design indexes; 5. Geotechnical engineering design and calculation; 6. Site formation; 7. Special soils in airfield area; 8. Adverse geologic actions in airfield area; 9. Special project design.
Chief development organization of this code:
China Airport Construction Group Corporation
Participating development organizations of this code:
CIGIS (China) Limited
Shanghai CAAC New Era Airport Design & Research Institute Co., Ltd.
Tongji University
Wuhan University
Contents
1 General provisions 1
2 Terms and symbols 1
2.1 Terms 1
2.2 Symbols 4
3 Basic requirements 5
4 Design indexes 8
4.1 General requirements 8
4.2 Indexes of foundation settlement deformation 8
4.3 Slope stability indexes 9
4.4 Foundation design control indexes 10
5 Geotechnical engineering design and calculation 12
5.1 General requirements 12
5.2 Deformation calculation 13
5.3 Stability calculation 15
6 Site formation 19
6.1 General requirements 20
6.2 Excavation and allocation of earthwork and stonework 20
6.3 Drainage 21
6.4 Affected area of pavement in airfield area, unpaved area in airfield area and area affecting fill slope stability 21
6.5 Terminal area and appurtenant building area 23
6.6 Reserved development area 24
7 Special soils in airfield area 24
7.1 General requirements 24
7.2 Weak soil 25
7.3 Collapsible loess 26
7.4 Expansive soil 29
7.5 Saline soil 31
7.6 Frozen soil 32
7.7 Filling 35
8 Adverse geologic actions in airfield area 35
8.1 General requirements 35
8.2 Karst 36
8.3 Landslides 38
8.4 Liquidation 40
8.5 Mined-out area 41
9 Special project design 42
9.1 General requirements 42
9.2 Construction projects without air service suspension in airfield area 42
9.3 High filling project 43
9.4 Sea reclamation project 45
Annex A Test method of subgrade reaction modulus 48
Annex B Test method of California bearing ratio 53
Annex C Explanation of wording in this code 61
Annex D Normative references 62
Code for geotechnical engineering design of airport
1 General provisions
1.0.1 This code is formulated with a view to standardizing the geotechnical engineering design for civil airport, based on the principle of safety and applicability, advanced technology, economic rationality, quality assurance, resource conservation and environment protection.
1.0.2 This code is applicable to the geotechnical engineering design for constructed and renovated (extended) civil airport (including the civil part of joint-used airport by military and civil units).
1.0.3 Comprehensive consideration shall be given to site division, adaptation to local conditions and using local materials in the geotechnical engineering design for civil airport; in addition, new technologies, materials and processes are advocated.
1.0.4 The geotechnical engineering design for civil airport shall meet the requirements of environmental assessment, reduce adverse effects on ecological environment, and prevent soil and water loss and secondary geological disasters.
1.0.5 In addition to the requirements of this code, the geotechnical engineering design for civil airport shall also meet the requirements of the current relevant standards of the nation.
2 Terms and symbols
2.1 Terms
I Terms of airport engineering
2.1.1 airport
area demarcated on land or water surface (including various buildings, plants and facilities), all or part of which may be used for take-off, landing and ground movement
2.1.2 airfield area
site used for take-off, landing, taxiing and parking of aircraft, including runway, runway strip, runway end safety area, taxiway, apron and areas around the airport that have limitations on obstacles
2.1.3 terminal area
general term of the landside part of airport land-air exchange area, including the terminal (terminal building), control center, parking building (lot), terminal traffic and service facilities, etc.
2.1.4 appurtenant building area
general term of areas except for the airfield area and the terminal area of the airport, including airport office area, comprehensive support area, airport freight area, life service area, etc.
2.1.5 affected area of pavement in airfield area
a certain foundation range under the pavement (including the shoulder) in the airfield area, that may affect or be affected by the deformation of pavement (including the shoulder)
2.1.6 unpaved area in airfield area
other airfield areas except for the affected area of pavement in airfield area
2.1.7 area affecting fill slope stability
area having an impact on the stability of fill slope
2.1.8 pavement bed
subgrade part within 0.80m below the bottom of the pavement, which is divided into upper pavement bed (0m~0.3m) and lower pavement bed (0.3m~0.80m)
II Terms of geotechnical engineering
2.1.9 geotechnical engineering
science and technology involved in the utilization, treatment or improvement of rocks and soil in civil engineering
2.1.10 subgrade
natural or artificial filling soil (rock) under the pavement, affected by the load transmitted by aircraft or vehicles on the pavement
2.1.11 foundation
natural or artificial filling soil (rock) bearing the load of building (structure)
2.1.12 filling body
earthwork and stonework manually filled from the original ground to the top subgrade surface or the design surface of site formation
2.1.13 post-construction settlement
settlement of pavement during the design working life after the completion of pavement construction
2.1.14 post-construction differential settlement
ratio of the absolute value of settlement difference between adjacent settlement calculation points or monitoring points to their horizontal distance
2.1.15 settlement during construction period
settlement of foundation from the start of foundation treatment or earthwork construction to the completion of pavement construction
2.1.16 subgrade reaction modulus
ratio of the pressure (load) to the deformation of a certain area measured by the subgrade reaction modulus test
2.1.17 special soils
rock-soil with special material composition, structure and unique engineering characteristics. This code covers weak soil, collapsible loess, expansive soil, saline soil, frozen soil, etc.
2.1.18 weak soil
soft plastic and flowing plastic cohesive soil and saturated loose silt
2.1.19 adverse geologic actions
geologic actions that may cause harm to the engineering due to internal force or external force of the earth, including karst, landslide, liquefaction, etc. in this code
2.1.20 high filling project
project with the maximum filling height or fill slope height (height difference from the top to the foot of the slope) greater than or equal to 20m for airports in mountainous or hilly areas
2.1.21 sea reclamation project
airport construction project on the site forming through artificial reclamation in sea areas or tidal flats
III Design terms
2.1.22 geotechnical engineering design for airport
activity of analyzing and demonstrating the geotechnical engineering problems involved in the airport construction and preparing the design documents according to the airport construction requirements
2.1.23 site formation
a process of transforming the natural original ground into the working face required by the project according to certain technical requirements
2.1.24 topography design
activity of determining the design surface of airport site formation according to certain technical requirements. It is also called vertical design
2.1.25 method of information design
design method of verification, optimization and perfection of design parameters and design scheme according to the data of information construction and construction survey feedback
2.2 Symbols
2.2.1 Geotechnical physical property
e——the void ratio;
γ——the gravity density, referred to as “unit weight”;
2.2.2 Geotechnical deformation parameters
Cs——the swelling index;
Cc——the compression index;
pc——the preconsolidation pressure.
2.2.3 Geotechnical strength parameters
c——the cohesion;
φ——the internal friction angle;
CBR——the California bearing ratio.
2.2.4 Other symbols
Fs——the slope stability safety factor;
k0——the subgrade reaction modulus;
s——the settlement.
3 Basic requirements
3.0.1 The following data shall be obtained before geotechnical engineering design:
1 site division and topography design data;
2 geotechnical engineering investigation data;
3 local geotechnical engineering management experience and construction conditions.
3.0.2 The grading of geotechnical engineering design for airport shall be based on the site complexity level and the foundation grade according to Table 3.0.2.
Table 3.0.2 Grading of geotechnical engineering design for airport
Condition for determining the geotechnical engineering design grade Geotechnical engineering design grade
Site complexity Foundation grade
Grade I site (complex site) Grades I, II and III Grade A
Grade II site (moderately complex site), Grade III site (simple site) Grade I
Grade II site (moderately complex site) Grades II and III Grade B
Grade III site (simple site) Grade II
Grade III site (simple site) Grade III Grade C
Note: The site complexity and the foundation grading are in accordance with MH/T 5025 Specifications for geotechnical investigation and surveying of airports.
3.0.3 The geotechnical engineering design for airport may be divided into three stages, i.e. scheme design, preliminary design and construction drawing design. The technical design may be added after the preliminary design according to the actual situation.
1 The geotechnical engineering design shall be combined with local experience for scheme comparison and selection to form the technical scheme study report.
2 The geotechnical engineering preliminary design shall be based on the scheme design for comparison and selection of design scheme to determine the design scheme and technical and economic indexes.
3 The geotechnical engineering technical design shall be carried out on the basis of preliminary design and field tests or special study results, to solve major and complicated technical problems that have not been completely solved by preliminary design, and propose optimized design scheme and technical and economic indexes.
4 The design of geotechnical engineering construction drawing shall be based on the preliminary design or technical design, to put forward construction design parameters and construction technical requirements.
3.0.4 The method of information design shall be adopted for the airport with Grade A geotechnical engineering design and should be adopted for the airport with Grade B geotechnical engineering design. The information design is applicable to construction stage and shall be based on the complete construction drawing design.
3.0.5 The site division shall be carried out based on the characteristics of the airport construction project and the general layout plan according to Table 3.0.5.
Table 3.0.5 Site division
Division Range
Affected area of pavement in airfield area The extension range of 1m~3m on both sides of the shoulder, where the filling area still needs to slope to the original ground at 1:0.6 ~ 1:0.4 to both sides
Unpaved area in
airfield area Area outside the affected area of pavement in airfield area, excluding the area affecting fill slope stability
Terminal area Including the terminal (terminal building), control center, parking building (lot), terminal traffic and service facilities, etc.
Appurtenant
building area Including airport office area, comprehensive support area, airport freight area, life service area, etc.
Reserved
development area Planned development area reserved within the site formation area
Area affecting fill
slope stability It is determined according to the filling height and the actual condition of the natural ground, through specific analysis
Note: The slope ratio of the two sides outside the shoulder of the filling area in the affected area of pavement in airfield area is 1:0.6 when the filling is coarse-grained soil such as medium sand, coarse sand and gravel, and 1:0.4 when the filling is fine-grained soil such as silty clay.
3.0.6 In the geotechnical engineering design for airport, the foundation settlement deformation and the slope stability shall be analyzed. When the foundation settlement deformation or slope stability does not meet the requirements and foundation treatment is required, the treated foundation shall be checked for settlement deformation or stability.
3.0.7 The design indexes, parameters and standards of the foundation or filling body shall be determined in the geotechnical engineering design in combination with excavation area and filling area formed by site division and site formation.
3.0.8 When determining the geotechnical engineering design scheme, the following steps should be followed:
1 Determine the purpose, scope and various technical indexes of geotechnical engineering design according to geotechnical engineering conditions and in combination with site division and functional requirements, and preliminarily select several geotechnical engineering technical schemes for consideration through analysis.
2 For the initially selected geotechnical engineering technical scheme, carry out a comprehensive technical and economic analysis from the aspects of technical reliability, feasibility, cost, construction period requirements, environmental effect, etc. to determine the geotechnical engineering design scheme.
3.0.9 For airports with Grade A geotechnical engineering design, field tests and special studies shall be carried out. For airports with Grade B geotechnical engineering design, field tests should be carried out. For airports with Grade C geotechnical engineering design, it is appropriate to carry out process construction tests. It is required to make test design, put forward the design parameters, construction technical requirements and testing requirements for the conduction of field test. Meanwhile, the monitoring requirements shall be put forward according to the actual situation.
3.0.10 The geotechnical engineering detection and monitoring requirements shall be put forward in the geotechnical engineering design. Those such as the scope, contents and time of detection and monitoring should be determined according to geotechnical engineering design contents and grades.
3.0.11 In the geotechnical engineering design, the surface and internal drainage systems shall be set up according to the actual situation.
3.0.12 In the geotechnical engineering design, the effect of municipal and transportation projects crossing the airport shall be considered and technical requirements shall be put forward for those crossing projects.
4 Design indexes
4.1 General requirements
4.1.1 The geotechnical engineering design indexes for civil airports shall include indexes of foundation settlement deformation, slope stability indexes, foundation design control indexes and other characteristic indexes.
4.1.2 The geotechnical engineering design indexes for civil airports shall be determined reasonably through comprehensive study based on natural conditions, engineering geological conditions, hydrogeological conditions, seismic conditions, site division, service load and local experience.
4.2 Indexes of foundation settlement deformation
4.2.1 The post-construction settlement and post-construction differential settlement within the design working life of the affected area of pavement in airfield area and the unpaved area in airfield area should not be greater than those specified in Table 4.2.1.
1 General provisions
2 Terms and symbols
2.1 Terms
2.2 Symbols
3 Basic requirements
4 Design indexes
4.1 General requirements
4.2 Indexes of foundation settlement deformation
4.3 Slope stability indexes
4.4 Foundation design control indexes
5 Geotechnical engineering design and calculation
5.1 General requirements
5.2 Deformation calculation
5.3 Stability calculation
6 Site formation
6.1 General requirements
6.2 Excavation and allocation of earthwork and stonework
6.3 Drainage
6.4 Affected area of pavement in airfield area, unpaved area in airfield area and area affecting fill slope stability
6.5 Terminal area and appurtenant building area
6.6 Reserved development area
7 Special soils in airfield area
7.1 General requirements
7.2 Weak soil
7.3 Collapsible loess
7.4 Expansive soil
7.5 Saline soil
7.6 Frozen soil
7.7 Filling
8 Adverse geologic actions in airfield area
