BS 1377-4-1990 Methods of test for soils for civil engineering purposes - Compaction-related tests《土木工程用土壤的试验方法 相关的压实试验》.pdf

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1、BRITISH STANDARD BS 1377-4: 1990 Incorporating Amendments Nos. 1 and 2 Methods of test for Soils for civil engineering purposes Part 4: Compaction-related tests UDC 624.131.3:631.4:620.1:624.138 BS 1377-4:1990 This British Standard, having been prepared under the Road Engineering Standards Policy Co

2、mmittee, was published under the authority of the Board of the BSI and comes into effect on 31 August 1990 BSI 6 December 2002 First published in 1948 First published in metric in 1975 The following BSI references relate to the work on this standard: Committee reference RDB/38 Draft for comment 88/1

3、0676 DC ISBN 0 580 18070 0 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Road Engineering Standards Policy Committee (RDB/-) to Technical Committee RDB/38, upon which the following bodies were represented: Association of Consulting Eng

4、ineers British Civil Engineering Test Equipment Manufacturers Association County Surveyors Society Department of the Environment (Property Services Agency) Department of the Environment (Building Research Establishment) Department of Transport Department of Transport (Transport and Road Research Lab

5、oratory) Co-opted members Amendments issued since publication Amd. No. Date of issue Comments 8259 January 1995 13925 6 December 2002 Indicated by a sideline in the marginBS 1377-4:1990 BSI 6 December 2002 i Contents Page Committees responsible Inside front cover Foreword iii 1S c o p e 1 2T e r m s

6、 a n d d e f i n i t i o n s 1 3 Determination of dry density/moisture content relationship 1 3.1General 1 3.2 Preparation of samples for compaction tests 2 3.3 Method using 2.5 kg rammer for soils with particles up to medium-gravel size 5 3.4 Method using 2.5 kg rammer for soils with some coarse gr

7、avel-size particles 8 3.5 Method using 4.5 kg rammer for soils with particles up to medium-gravel size 9 3.6 Method using 4.5 kg rammer for soils with some coarse gravel-size particles 10 3.7 Method using vibrating hammer 12 4 Determination of maximum and minimum dry densities for granular soils 15

8、4.1 General 15 4.2 Determination of maximum density of sands 15 4.3 Maximum density of gravelly soils 18 4.4 Minimum density of sands 20 4.5 Minimum density of gravelly soils 21 4.6 Derivation of density index 22 5 Determination of the moisture condition value (MCV) 22 5.1 General 22 5.2 Apparatus 2

9、3 5.3 Checking the moisture condition apparatus 24 5.4 Determination of the MCV of a sample of soil at its natural moisture content 24 5.5 Determination of the MCV/moisture content relation of a soil 26 5.6 Rapid assessment of whether or not a soil is stronger than a precalibrated standard 27 6 Dete

10、rmination of the chalk crushing value 28 6.1 General 28 6.2 Apparatus 28 6.3 Checking the moisture condition apparatus 28 6.4 Determination of the chalk crushing value (CCV) 28 7 Determination of the California Bearing Ratio (CBR) 30 7.1 General 30 7.2 Preparation of test sample 30 7.3 Soaking 35 7.

11、4 Penetration test procedure 36 7.5 Calculation and plotting 37 7.6 Test report 39 Appendix A Typical test data and calculation forms 54BS 1377-4:1990 ii BSI 6 December 2002 Page Figure 1 Grading limits relating to sample preparation procedures for compaction tests 39 Figure 2 Flow chart representin

12、g sample preparation methods for compaction tests 40 Figure 3 Mould for compaction test (1 L mould) 41 Figure 4 2.5 kg rammer for compaction test 42 Figure 5 4.5 kg rammer for compaction test 43 Figure 6 Dry density/moisture content relationship curve 44 Figure 7 Tampers for vibrating hammer compact

13、ion test 45 Figure 8 Moisture condition apparatus 46 Figure 9 Relationship between change in penetration and number of blows 47 Figure 10 Alternative type of relationship between change in penetration and number of blows 47 Figure 11 Flow chart representing sample preparation methods for the CBR tes

14、t 48 Figure 12 Cylindrical mould for the determination of the California Bearing Ratio 49 Figure 13 Plug and collar extension for use with cylindrical mould for the determination of the California Bearing Ratio 49 Figure 14 Apparatus for measuring the swelling of a sample during soaking for the CBR

15、test 50 Figure 15 General arrangement of apparatus for the CBR test 51 Figure 16 Typical CBR test result curves 52 Figure 17 Force-penetration curves for a CBR value of 100 % and other CBR values 53 Table 1 Summary of compaction procedures 2 Table 2 Summary of sample preparation methods 4 Table 3 St

16、andard force-penetration relationships for 100 % CBR 38 Publications referred to Inside back coverBS 1377-4:1990 BSI 6 December 2002 iii Foreword This Part of BS 1377 has been prepared under the direction of the Road Engineering Standards Policy Committee. It is a revision of Clause 4 of BS 1377:197

17、5 which is superseded by amendment. BS 1377 was first published in 1948 and first appeared in metric form in 1975. BS 1377:1975 which has now been withdrawn is replaced by the following Parts of BS 1377:1990: Part 1: General requirements and sample preparation; Part 2: Classification tests; Part 3:

18、Chemical and electro-chemical tests; Part 4: Compaction-related tests; Part 5: Compressibility, permeability and durability tests; Part 6: Consolidation and permeability tests in hydraulic cells and with pore pressure measurement; Part 7: Shear strength tests (total stress); Part 8: Shear strength t

19、ests (effective stress); Part 9: In-situ tests. Reference should be made to Part 1 of BS 1377 for further information about each of the Parts. The following methods of test, additional to those described in the 1975 standard, have been introduced. Determination of the maximum and minimum densities o

20、f granular soils. Determination of the moisture condition value. Determination of the chalk crushing value. In the dry density/moisture relationship tests, and the California Bearing Ratio (CBR) test, sample preparation procedures have been set out in more detail than before, with explanatory flow d

21、iagrams. It has been assumed in the drafting of this British Standard that the execution of its provisions is entrusted to appropriately qualified and experienced personnel, for whose guidance it has been prepared. This publication does not purport to include all the necessary provisions of a contra

22、ct. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i to iv, pages 1 to 63 and a back cover. The BSI copyright notice

23、displayed in this document indicates when the document was last issued. A sideline in the margin indicates the most recent changes by amendment.iv blankBS 1377-4:1990 BSI 6 December 2002 1 1 Scope This Part of BS 1377 describes methods of test for determining characteristics related to the compactio

24、n of soils, which can be used as a basis for specifying requirements for soils compacted in the field. This Part also includes a method for assessing an empirical strength criterion (the CBR value) of a compacted or undisturbed soil used as a sub-grade material for pavement construction. Reference i

25、s made to some of the classification tests described in BS 1377-2. Reference is made to BS 1377-1 for general requirements that are relevant to all Parts of this standard, and for methods of preliminary preparation of soil for testing. NOTE The titles of the publications referred to in this standard

26、 are listed on the inside back cover. 2 Terms and definitions For the purposes of this Part of BS 1377, the definitions given in BS 1377-1 apply. 3 Determination of dry density/moisture content relationship 3.1 General 3.1.1 Principle. Compaction of soil is the process by which the solid particles a

27、re packed more closely together, usually by mechanical means, thereby increasing the dry density of the soil. The dry density which can be achieved depends on the degree of compaction applied and on the amount of water present in the soil. (The terms used in compaction tests are illustrated in Figur

28、e 6.) For a given degree of compaction of a given cohesive soil there is an optimum moisture content at which the dry density obtained reaches a maximum value. For cohesionless soils an optimum moisture content might be difficult to define. NOTE For some highly permeable soils such as clean gravels,

29、 uniformly graded and coarse clean sands, the results of the laboratory compaction test may provide only a poor guide for specifications on field compaction. The laboratory test might indicate meaningless values of moisture content in these free-draining materials and the maximum dry density is ofte

30、n lower than the state of compaction which can be readily obtained in the field. For these soils one of the maximum dry density tests described in Clause 4 would be more appropriate. The objective of the tests described in this clause is to obtain relationships between compacted dry density and soil

31、 moisture content, using two magnitudes of manual compactive effort, or compaction by vibration. 3.1.2 Types of test. Three types of compaction test are described, each with procedural variations related to the nature of the soil. The first is the light manual compaction test in which a 2.5 kg ramme

32、r is used. The second is the heavy manual compaction test which is similar but gives a much greater degree of compaction by using a 4.5 kg rammer with a greater drop on thinner layers of soil. For both these tests a compaction mould of 1 L internal volume is used for soil in which all particles pass

33、 a 20 mm test sieve. If there is a limited amount of particles up to 37.5 mm size, equivalent tests are carried out in the larger California Bearing Ratio (CBR) mould. NOTE 1 Specifications for compaction by rammer in the CBR mould are based on the same compactive effort per unit volume of soil as i

34、n the 1 L compaction mould. The variable effects of side wall friction might result in differences between the densities achieved in the two moulds. For a series of tests on a particular soil, one size of mould should be used consistently. NOTE 2 If more than 30 % of material is retained on a 20 mm

35、test sieve the material is too coarse to be tested. The third type of test makes use of a vibrating hammer, and is intended mainly for granular soils passing a 37.5 mm test sieve, with no more than 30 % retained on a 20 mm test sieve. The soil is compacted into a CBR mould. For each type of test, al

36、ternative procedures depend on whether or not the soil contains particles susceptible to crushing during compaction. Methods of sample preparation covering most possible requirements are described in 3.2. Test procedures are described separately in 3.3, 3.4, 3.5, 3.6 and 3.7. The compaction procedur

37、es are summarized in Table 1.BS 1377-4:1990 2 BSI 6 December 2002 Table 1 Summary of compaction procedures 3.2 Preparation of samples for compaction tests 3.2.1 General. The method of preparation of samples for these tests, and the quantity of soil required, depend on the size of the largest particl

38、es present and on whether or not the soil particles are susceptible to crushing during compaction. The assessment of these factors is covered in 3.2.2. For soils containing particles not susceptible to crushing, one sample only is required for test and it can be used several times after progressivel

39、y increasing the amount of water. Relevant sample preparation methods are described in 3.2.4 and 3.2.5. For soils containing particles that are susceptible to crushing, it is necessary to prepare separate batches of soil at different moisture contents, each for compacting once only, otherwise the ch

40、aracteristics of the material will progressively change after each application of compaction. Consequently, a much larger sample is required. Relevant sample preparation methods are described in 3.2.6 and 3.2.7. For stiff, cohesive soils which need to be shredded or chopped into small lumps, the res

41、ult of a compaction test depends on the size of the resulting pieces. Furthermore, the densities obtained in the test will not necessarily be directly related to densities obtained in-situ. The method used for breaking down cohesive soil, and the size of pieces obtained, should be recorded. Suggeste

42、d methods are to shred the soil so that it could pass through a 5 mm test sieve, or to chop it into pieces, e.g. to pass a 20 mm test sieve. The requirements of Part 1 of this standard, where appropriate, shall apply to this test method. 3.2.2 Preliminary assessment. The initial soil sample for test

43、ing shall be obtained in accordance with the procedure described in 7.6.1 to 7.6.3 of BS 1377-1:1990. The procedures to be used for sample preparation and for carrying out the compaction test shall be selected on the basis of the following assessment. a) Ascertain whether the soil particles are susc

44、eptible to crushing during compaction. If in doubt assume that they are susceptible. NOTE The soil should be considered susceptible to crushing during compaction if the sample contains granular material of a soft nature, e.g. soft limestone, sandstone, etc., which would be reduced in size by the act

45、ion of the 2.5 kg rammer. The procedure described in 3.3.4.2, 3.4.4.2, 3.5.4.2, and 3.6.4.2 for soils susceptible to crushing during compaction should be applied to all soils if it is practicable to do so. b) Determine the approximate percentages (to an accuracy of 5 %) by mass of particles in the s

46、oil sample passing the 20 mm and 37.5 mm test sieves. If the material used for this assessment is to be used for the compaction test it shall not be dried, and the dry mass of soil finer than 20 mm may be determined by measuring the moisture content using a representative portion. If enough soil is

47、available to meet the requirements of Clause 9 of BS 1377-2:1990 a separate sample may be used for this sieving operation. Test procedure clause reference Mass of rammer kg Soil particles susceptible to crushing Type of mould used 3.3.4.1 3.5.4.1 2.5 4.5 ) ) no (a) ) 1L 3.3.4.2 3.5.4.2 2.5 4.5 ) ) y

48、es (b) ) 1L 3.4.4.1 3.6.4.1 2.5 4.5 ) ) no (a) ) CBR 3.4.4.2 3.6.4.2 2.5 4.5 ) ) yes (b) ) CBR 3.7.5.1 3.7.5.2 (vibrating hammer) no (a) yes (b) CBR 1 L = 1 L compaction mould, as described in 3.3.2.1. CBR = CBR mould, as described in 7.2.2.2. (a) and (b) refer to methods in Table 2.BS 1377-4:1990 B

49、SI 6 December 2002 3 c) On the basis of these percentages the soil can be assigned to one of the grading zones (1) to (5) in Table 2, which are also shown diagrammatically in Figure 1. If a grading curve passes through more than one zone the highest-numbered zone applies. A soil with a grading curve passing through zone X is not suitable for these tests. d) The method of sample preparation, the minimum mass of soil required, and the type of mo