马来西亚槟城第二跨海大桥
工程地质详细勘察技术要求
Technical requirement for site investigation for Penang Second Crossing Bridge, Malaysia
1 目点与任务
在调查收集桥位区地质资料的基础上，查明桥址区的工程地质条件, 为施工图设计方案提供依据。根据目前确定的桥位及桥型方案，结合前期的勘察资料，开展工程地质详细勘察工作，查明桥址区地形地貌、地层岩性、地质构造、水文地质、不良地质等问题。
1 Objective
The objective of the proposed geological investigation works is to identify the subsurface soil conditions and obtain the relevant geological information along the proposed bridge alignment in order to provide basis for engineering design of the foundation. Based on the tentative confirmed location and alignment of the bridge proposal, the detailed geological investigation works shall be carried out, in combination with the existing soil investigation information, to identify the subsurface soil
profile, bedrock geology, ground water condition and the presence of any unfavourable soil conditions, etc., along the bridge alignment.
2 依据规范
（1）Code of practice for site investigations BS5930:1999
（2）British Standard Methods of test for Soils for civil engineering purposes BS1377：1999
（3）参考马来西亚当地与本工程相关的标准、规范等
2 Code of Practice
The geological investigation works shall be carried out in accordance to the British Standards BS5930-1999 “Code of Practice for Soil Investigations” and BS1377-1999 “Code of Practice for Method of Test for Soil for Civil Engineering Purposes” and any other relevant technical standards.
3 总体技术要求
本项目的勘察承包商应具有符合马来西亚国家法律规定的勘察资质证明文件以及执业注册资格，勘察承包商应在最终勘察报告的成果署名，并承担全部的工程勘察及岩土工程分析工作的法律责任，其勘察技术成果报告需满足马方政府
部门的审批要求，并负责该审批与上报等工作。所有的设备仪器的配置均必须根据英标工程规范的要求配置，并经马来西亚国家有关计量认证部门的标定。
3 General technical requirement
The contractor shall possess certificate of business registration and certificate of statutory bodies registration for geological investigation work which recognized by Malaysia Statutory Department. The contractor shall state its name in the factual report and hold legal responsibility of the soil investigation and geotechnical interpretation works. The factual report and geotechnical Interpretation report shall fulfill the requirements of Malaysian Statutory Department. The contractor shall undertake obligation in line with Malaysian Statutory Department to examine and submit the factual and geotechnical Interpretation report. All equipment and instruments for the geological investigation work shall be in accordance with the British Standards and shall be calibrated and validated by the related Malaysian statutory department.
（1）平面坐标及高程控制系统：
工程勘察平面坐标采用马来西亚的MRSO坐标系，高程系统采用马来西亚ACD（Admiralty Chart Datum）高程基准。钻孔定位坐标放样精度、钻孔孔口高程误差控制应满足BS5930:1999要求。
(1) Control system of plane coordinate and elevation
In the site investigation, the Malaysian local coordinate system i.e. MRSO is adopted for the plane coordinate and ACD (Admiralty Chart Datum) used for elevation system. The tolerance for location and elevation of boreholes shall be in accordance with the requirements of BS5930:1999.
（2）钻孔性质的要求：
总体勘察的钻孔50%为技术性控制孔，50%为一般地质探查孔，在技术孔中须按本技术要求的规定严格采取原状土样、岩石试样，并进行原位测试等现场工作；在一般性地质孔中主要用于地层鉴别与划分，并重点测试松散层、全、强风化层等位置的标准贯入试验、动探试验数据等，以及补充采取邻近技术孔漏取的原状土样、岩样等。
(2) Requirements for boreholes
50% of total boreholes shall be technical boreholes, and remaining 50% common geological boreholes. In technical boreholes, undisturbed soil samples and rock cores shall be taken for laboratory test and in-situ testing in accordance with the technical requirements.
Common geological borehole is mainly used to determine the soil profile and identify the soil layers. For certain soil layers of loose soil, completely weathered soil and highly weathered soil, in-situ tests e.g. SPT, other dynamic exploration tests shall be carried out. The common geological boreholes also serve to provide any undisturbed soil samples or rock cores which have not been taken in adjacent technical boreholes. Based on all these boreholes totally and quantitative physical-mechanics
parameters of soil and rock can be obtained for bridge foundation design.
（3）钻孔取芯要求：
要求所有钻孔（技术孔与一般性地质孔）均进行全孔段取芯。并放置在标准的岩芯箱里。岩芯采取率要求在坚硬完整的岩层中，不宜小于85％，在强风化、破碎的岩层中，不宜小于50％；重点研究的孔段（断层破碎带、滑坡滑动带等）应尽量提高岩芯采取率。粘性土地层不小于80%，砂类土地层不小于65%。
钻孔孔径的要求以满足采取原状土样供做室内土的物理与力学试验的土样为控制条件，岩石试验应满足室内岩石试验样品制备要求。
(3) Requirements for Sampling
Full sectional sampling shall be conducted for all boreholes (technical boreholes & common boreholes) and the soil samples and rock cores shall be stored in standard sample store box. The recovery of soil samples/ rock cores shall be equal to or greater than 85% in hard and intact rock layer and the recovery of soil sampes/ rock cores for highly weathered and fractured rock shall be equal to or greater than 50%. For certain borehole sections at different soil interfaces, fractured zones and sliding layer, the recovery of soil samples/rock cores shall adequately be increased. The sampling recovery for clay and sandy soil shall be equal to or greater than 80% and 65% respectively.
The diameter of boreholes shall be in accordance with the requirements of sampling for laboratory tests.
（4）钻孔中原位测试
钻孔中所有测试工作必须满足BS规范的要求，包括测试仪器等必须采用符合BS标准以及测试仪器标定等要求进行现场测试工作。
?在所有钻孔中的松散层内均应进行标准贯入试验，标贯试验应在采取原状土样后，立即进行。以取得粘性土和砂性土的力学参数，采取适当数量的扰动砂样进行颗粒分析试验。
?技术性钻孔标准贯入试验的间隔应为2m，在2m中间布置采取原状土样，即1次标准贯入试验→钻探采芯→原状土样→标准贯入试验→钻探采芯→原状土样……。
?一般性地质孔的标准贯入试验应视地层变化，布置3~5m试验间隔为宜。
?十字板剪切试验均匀布置10%钻孔的浅部较软地层中进行，单孔内试验1次间隔视地层厚度变化布置1~2m为宜，各点均应进行原状土与重塑土剪切试验，以求得软土的灵敏度。
?用于砂土液化判别的钻孔每公里间隔至少布置1孔，钻孔判别深度范围内的标准贯入试验间距按1米进行，并采取标贯器中的扰动样留作试验室的颗分与粘粒含量的测定；在勘察报告中提供标贯实测锤击数。
?均匀布置约10个钻孔的波速测试工作，要求在钻孔内横波、纵波同时测试，测试垂向间距应控制在1m以内，并根据地层变化随时调整测试间隔，测试深度应从孔口到达孔底。
(4) Requirements for In-situ tests in borehole
All in-situ tests in boreholes and equipment and instruments used shall fulfill the requirements of relevant British Standards.
SPT shall be carried out for all loose soil layers in all boreholes.
SPT tests shall be carried out right after undisturbed sampling in
the boreholes in order to obtain mechanical parameters for
cohesive and cohesiveless soil. Several disturbed sand samples
shall also be taken for sieving tests.
In technical boreholes, SPT shall be conducted at 2m intervals.
Undisturbed soil sample shall be taken within the 2m interval i.e.
the process shall be SPT Sample coring undisturbed
sampling SPT Sample coring undisturbed sampling and
so on.
In common boreholes, SPT shall be conducted at about 3-5m
intervals depending on the changes of soil strata.
Vane shear test shall be carried out uniformly in 10% of
boreholes at shallow and relatively soft soil layers. It shall be
conducted at about 1-2m intervals depending on the thickness
and changes of the soil strata. The test shall be carried out for
undisturbed soil and remoulded soil in order to achieve the soil
sensitivity.
At least one borehole at every 1 kilometer interval along the
proposed bridge alignment will be used to identify and evaluate
the possibility of sandy soil liquefaction. SPT tests for the
boreholes shall be carried out at 1m intervals throughout the
depth of sandy layer. The disturbed soil sample taken during SPT
tests shall be stored for laboratory test (particle size distribution
and sedimentation test). The actual SPT N value shall be
recorded in the Soil Investigation report.
About 10 boreholes at equal spaced intervals along the
proposed bridge alignment shall be used for vertical seismic
profiling (VSP) test. The shear wave and longitudinal wave shall
be measured at the same time. The interval of wave test in
borehole shall not exceed 1 meter, but the distance can be
adjusted according to the change of soil layer. The depth of test
shall be measured based on top to the bottom of boreholes.（5）钻孔中原状土取样
?技术孔中钻孔取样
在粘性土、砂性土层中，一般每2.0m应取原状样一件，遇有土层变化，应立即取样，以保证薄层不漏样。如层厚大于或等于5m，可分别在上、中、下各取代表性土样1件，原状土样的取样最大间隔不大于3.0m。
在基岩地层中，全风化层取样要求同土层，强风化基岩岩芯较完整时采样间隔为2～3m，岩芯较破碎时，可以进行点荷载试验以弥补强风化层的岩石力学指标；弱风化、微风化为3～5m左右。如层厚大于或等于5m，可分别在上、中、下各取代表性岩样1组。
?一般性地质孔取样
一般性地质孔中的采样主要是弥补临近技术孔中漏取的原状土样、岩样，对于较厚的砂性土可以采取适当的扰动土样进行室内筛分试验等。
(5) Requirements for undisturbed soil sampling
①undisturbed soil sampling in technical boreholes
In clay and sandy soil, one undisturbed sample shall generally be taken at 2.0m intervals. If there are changes of soil strata, undisturbed sample shall be taken immediately to avoid missing information for thin soil layer. For thick soil layer of 5m or greater, undisturbed samples can be taken at topmost, middle and bottommost of the soil layer. However, the maximum interval of undisturbed samples shall not exceed 3m.
For bedrock strata, the requirement of undisturbed sampling for completely weathered layer shall follow that for soil layer in boreholes. For highly weathered rock, the interval for undisturbed sampling shall be 2.0 -3.0m if the sampling recovery is high. If the rock recovery is relatively low, point bearing test shall be carried out to obtain its mechanical parameter. For weakly or slightly weathered rock, the sampling interval shall be about 3.0-5.0m. for thick bedrock of 5 m or greater, three samples can be taken at topmost, middle and bottommost of the rock layer or at the termination depth of the boreholes.
②undisturbed soil sampling in common borehole,
Common boreholes are mainly used to supplement undisturbed soil samples or rock cores for adjacent technical boreholes. For thick sandy soil layer, disturbed sandy soil samples can be taken for sieving test.（6）钻孔终孔原则
钻孔的终孔深度应以设计钻孔深度为控制条件，终孔深度附近地层较差时，应适当加深，并由勘察单位技术负责人根据具体情况确定，并报告设计代表。
(6) Termination depth of boreholes
The termination depth of every borehole shall follow the design depth. If the termination depth shows weaker soil/rock layer, the depth of the borehole shall be extended upon confirmation from the technical personnel on site. The changes shall report to the design personnel.
4针对不同桩基形式的勘察细部要求
4 Detailed requirements according to different types of foundation
（1）钻孔灌注桩
钻孔灌注桩基础主要用在桩号K1+863.46~ K2+338.46的主桥范围内，以及K16+088.46~ K16+913.46在主桥区应重点做好以下工作：
?保证技术性钻孔的原状土样的采集数量与质量，严格按照2m的取样间隔采取原状土样，并进行标准贯入实验，如遇土层变化，应加密采取原状土样以及标准贯入试验。