琼州海峡海底电缆铺设可行性研究
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摘要
本文研究的琼州海峡(广东省徐闻县的南岭村至海南省玉包角)的海底电缆路由勘察项目是在收集勘察区域附近的自然环境条件和工程地质条件历史资料的基础上,并且对路由区进行详细的环境地质调查。通过使用单波束、旁扫声纳、浅地层剖面等仪器设备进行勘察,并对勘察成果资料进行解析判读,初步查明路由区水深、海底地形、地貌特征及浅地层岩性、地质构造、不良地质现象等问题;初步查明各种地质现象的具体位置、规模、性质、产状,并评价它们对路由管道铺设稳定性的影响程度,为工程建设以及日后的海底管道铺设、维护提供切实可靠的数据和资料。
主要从以下几个方面对琼州海峡海底电缆铺设的可行性进行了全面的、多学科的研究与评价,并得出以下结论:
1、3条路由的长度接近,通过的地质地貌单元相同。路由0-12.3km段,地形平缓,除近岸局部中度风化玄武岩的埋深小外,大部分区域的软塑-可塑状态沉积物厚度超过3m,有利于海底电缆的埋设和安全运行。路由12.3-20.7km段(长约8.4km),水深截面呈锯齿状,表层松散沉积物薄,突起地形武岩埋深小,局部有零星的珊瑚礁分布,南部隆起带北坡受滑坡威胁较大,工程地质条件较差。路由20.7-30.0km段(长约9.3km),地形起伏不大,可塑-硬塑状态沉积物厚度超过3m,除海岸线附近玄武岩埋深较小外,工程地质条件良好。
2、不良的地质现象主要是活动沙波、陡坡地形、滑坡、浅埋玄武岩和珊瑚礁,路由北段堆积区局部有流塑的软弱淤泥质粘土夹层。
3、CPT静力测试分析结果表明,路由区内多处砂体在地震等外力作用下,有发生液化的可能,但砂体液化对海底电缆的影响不大,而砂体发生液化后其状态变得更稳定。
4、两岸终端站区域的抗震设防烈度为7度,地震动峰值加速度为0.15g,地震动反应谱特征周期为0.35s。
5、腐蚀性测试结果表明,路由区内的沉积物和海水的腐蚀性不强,但路由北段3-7km、水深4-10m的海域,2m以浅的硫酸盐还原细菌含量较大,要求3-7km段电缆的埋深在2m以上。
6、路由区海域内表层流的理论最大可能潮流流速的最大值为286cm/s,底层海流的理论最大值为198cm/s,对海底电缆的施工和安全维护影响较大。
The study of the Qiongzhou Strait(from the Nanling Village in Xuwen County of Guangdong Province to Yubaojiao of Hainan Province) Submarine Cable routing survey project is in the collection of survey conditions and the natural environment of the region surrounding geological conditions on the basis of historical information, and to conduct detailed environmental Road from District geological survey. According to the bathymetric and topographic method: we will use single beam、side scan sonar、sub-bottom profiler and other equipments, to carry out the sub-bottom profile survey, then analyzing and interpretation the data results of the survey. The aim of the survey is to preliminarily prospect the water depth, the seabed topographic features and the petrography of the sub-bottom profile, the geological structure, the adverse geological phenomena, etc; to preliminarily explore the specific location, scales, nature, occurrences of the various geological phenomena, and to evaluate their influence on the stability of the pipeline laying along the route. We believe that all these work can provide effective and reliable data or information for the engineering construction and the submarine pipeline laying and maintenance in the area.
On feasibility study and evaluation of the Qiongzhou Strait Submarine Cable laying, we will mainly from the following comprehensive, multidisciplinary aspects to analysis and expound, and conclusions are drawn as follows:
1、The three routes extend for approximately equal length and pass through basically identical geological and topographical units. In the 0-12.3km section of the route, the topography is slowly inclined, and except the moderately weathered basalt is buried at shallow depth in some local off-shore areas, the soft plastic to plastic sediments exceed 3m in thickness in most of the area, which is favorable for the burial construction and safe operation of submarine cable. In the 12.3-20.7km section (about 8.4km long) of the route, the water depth section takes the serrate form, the surface loose sediments are generally thin, basalts are buried shallow in protrusive relief, and locally coral reefs occur sporadically. Generally, landslip may easily occur in the north slope of the south uplifted zone, and the engineering geological conditions here are poor. In the 20.7-30.0km section (about 9.3km long) of the route, the topography is not remarkably undulating, here the plastic-hard plastic sediments are generally over 3m in thickness. Except the basalt is general buried at shallow depth nearby the coast lines, the engineering geological condition is favorable in general.
2、Adverse geological phenomena mainly include active sand wave, steep slope topography, shallow-buried basalt and coral reefs, as well as the weak silt clay inter- layers occurring locally in the accumulation area in the north section of the route.
3、CPT static force testing results indicate that possibility of liquefaction exists when sand bodies in the route area are subject to exogenic forces such as earthquake, etc., just the sand-liquefaction has little effect on the submarine cable, even more; the route area state will become more stable after the sand-liquefaction is occurred.
4、In the terminal station areas around the two coasts, the anti-seismic fortified intensity is set at grade 7 on the Richter's scale, at a peak ground acceleration of 0.15g for a ground motion, and at an characteristic period of 0.35s on a ground motion response spectrum.
5、Corrosive test results indicate that the sediments and sea water and in the route area are not strongly corrosive. However, in the sea area with a water depth of 4-10m in the 3-7km section of the north part of the route area, a great number of sulphate deoxidizing bacteria occur at a depth of <2m. Consequently, it is suggested that the cable in the section of 3-7km shall be buried at a depth of >2m.
6、The theoretically possible maximum tidal current speed for the surface layer current in the route sea area is 286cm/s, while the theoretically maximum value for the bottom layer sea current is 198cm/s, which will has significant influence on the construction and safety maintenance of submarine cable.
主要从以下几个方面对琼州海峡海底电缆铺设的可行性进行了全面的、多学科的研究与评价,并得出以下结论:
1、3条路由的长度接近,通过的地质地貌单元相同。路由0-12.3km段,地形平缓,除近岸局部中度风化玄武岩的埋深小外,大部分区域的软塑-可塑状态沉积物厚度超过3m,有利于海底电缆的埋设和安全运行。路由12.3-20.7km段(长约8.4km),水深截面呈锯齿状,表层松散沉积物薄,突起地形武岩埋深小,局部有零星的珊瑚礁分布,南部隆起带北坡受滑坡威胁较大,工程地质条件较差。路由20.7-30.0km段(长约9.3km),地形起伏不大,可塑-硬塑状态沉积物厚度超过3m,除海岸线附近玄武岩埋深较小外,工程地质条件良好。
2、不良的地质现象主要是活动沙波、陡坡地形、滑坡、浅埋玄武岩和珊瑚礁,路由北段堆积区局部有流塑的软弱淤泥质粘土夹层。
3、CPT静力测试分析结果表明,路由区内多处砂体在地震等外力作用下,有发生液化的可能,但砂体液化对海底电缆的影响不大,而砂体发生液化后其状态变得更稳定。
4、两岸终端站区域的抗震设防烈度为7度,地震动峰值加速度为0.15g,地震动反应谱特征周期为0.35s。
5、腐蚀性测试结果表明,路由区内的沉积物和海水的腐蚀性不强,但路由北段3-7km、水深4-10m的海域,2m以浅的硫酸盐还原细菌含量较大,要求3-7km段电缆的埋深在2m以上。
6、路由区海域内表层流的理论最大可能潮流流速的最大值为286cm/s,底层海流的理论最大值为198cm/s,对海底电缆的施工和安全维护影响较大。
The study of the Qiongzhou Strait(from the Nanling Village in Xuwen County of Guangdong Province to Yubaojiao of Hainan Province) Submarine Cable routing survey project is in the collection of survey conditions and the natural environment of the region surrounding geological conditions on the basis of historical information, and to conduct detailed environmental Road from District geological survey. According to the bathymetric and topographic method: we will use single beam、side scan sonar、sub-bottom profiler and other equipments, to carry out the sub-bottom profile survey, then analyzing and interpretation the data results of the survey. The aim of the survey is to preliminarily prospect the water depth, the seabed topographic features and the petrography of the sub-bottom profile, the geological structure, the adverse geological phenomena, etc; to preliminarily explore the specific location, scales, nature, occurrences of the various geological phenomena, and to evaluate their influence on the stability of the pipeline laying along the route. We believe that all these work can provide effective and reliable data or information for the engineering construction and the submarine pipeline laying and maintenance in the area.
On feasibility study and evaluation of the Qiongzhou Strait Submarine Cable laying, we will mainly from the following comprehensive, multidisciplinary aspects to analysis and expound, and conclusions are drawn as follows:
1、The three routes extend for approximately equal length and pass through basically identical geological and topographical units. In the 0-12.3km section of the route, the topography is slowly inclined, and except the moderately weathered basalt is buried at shallow depth in some local off-shore areas, the soft plastic to plastic sediments exceed 3m in thickness in most of the area, which is favorable for the burial construction and safe operation of submarine cable. In the 12.3-20.7km section (about 8.4km long) of the route, the water depth section takes the serrate form, the surface loose sediments are generally thin, basalts are buried shallow in protrusive relief, and locally coral reefs occur sporadically. Generally, landslip may easily occur in the north slope of the south uplifted zone, and the engineering geological conditions here are poor. In the 20.7-30.0km section (about 9.3km long) of the route, the topography is not remarkably undulating, here the plastic-hard plastic sediments are generally over 3m in thickness. Except the basalt is general buried at shallow depth nearby the coast lines, the engineering geological condition is favorable in general.
2、Adverse geological phenomena mainly include active sand wave, steep slope topography, shallow-buried basalt and coral reefs, as well as the weak silt clay inter- layers occurring locally in the accumulation area in the north section of the route.
3、CPT static force testing results indicate that possibility of liquefaction exists when sand bodies in the route area are subject to exogenic forces such as earthquake, etc., just the sand-liquefaction has little effect on the submarine cable, even more; the route area state will become more stable after the sand-liquefaction is occurred.
4、In the terminal station areas around the two coasts, the anti-seismic fortified intensity is set at grade 7 on the Richter's scale, at a peak ground acceleration of 0.15g for a ground motion, and at an characteristic period of 0.35s on a ground motion response spectrum.
5、Corrosive test results indicate that the sediments and sea water and in the route area are not strongly corrosive. However, in the sea area with a water depth of 4-10m in the 3-7km section of the north part of the route area, a great number of sulphate deoxidizing bacteria occur at a depth of <2m. Consequently, it is suggested that the cable in the section of 3-7km shall be buried at a depth of >2m.
6、The theoretically possible maximum tidal current speed for the surface layer current in the route sea area is 286cm/s, while the theoretically maximum value for the bottom layer sea current is 198cm/s, which will has significant influence on the construction and safety maintenance of submarine cable.
引文
[1]方国洪、郑文振、陈宗镛、王骥,《潮汐和潮流的分析和预报》[M],北京:海洋出版社,1986。
[2]中华人民共和国交通部,《海港水文规范》[S],北京:人民交通出版社,2000。
[3]侍茂崇、陈春华、黄方、叶安乐,《琼州海峡冬末春初潮余流场特征》[J],海洋学报,1998,20(1):1-10。
[4]国家海洋局南海海洋调查技术中心,《琼州海峡跨海工程可行性研究基础资料 潮、流、悬沙调查报告》,1998。
[5]交通部第二航务工程勘察设计院《海南马村港总体布局规划》,1994。
[6]水利电力部华东电力设计院,《海口火电厂2×125MW机组工程设计报告 水文气象报告》,1988。
[7]陈上及、马继瑞,《海洋数据处理分析方法及其应用》[S],北京:海洋出版社,1991.
[8]国家海洋局、国家测绘局,《中国海岸带和海涂资源综合调查图集 广东省粤西分册、海南岛分册》,1989。
[9]《广东省海岸带和海涂资源综合调查报告》,海洋出版社,1998。
[10]地矿部第二海洋地质调查人队、国家海洋局南海分局,《琼州海峡西部天然气管道选线工程补充勘察报告》,1986年3月。
[11]国家电力公司中南电力设计院,《南方电网与海南电网联网工程可行性研究报告》,第一卷“总论”和第四卷“规划选线报告”,2003年3月。
[12]国家海洋局南海海洋工程勘察与环境研究院,《南方电网与海南电网联网工程琼州海峡海底电缆路由桌面研究报告》,2003年6月。
[13]海南省海洋开发规划研究院,《粤海铁路工程琼州海峡海底光缆路由桌面研究报告》,2001年10月。
[14]青岛海洋工程勘察设计研究院,《中国联通徐闻-海口海底光缆路由桌面研究报告》,2001年8月。
[15]地矿部第二海洋地质调查大队,《琼州海峡跨海工程地球物理调查报告》,1995。
[16]金波等,“琼州海峡东、西口地貌特征及其成因初探”,《海洋地质研究》VOL.2,NO.4,地质出版社,1982。
[17]彭学超,“琼州海峡地质构造特征及成因分析”,《南海地质研究》,地质出版社,2000年12月。
[18]李少英、宋运法、蔡树群、王盛安,《琼州海峡的流、浪、潮要述》,[J],南海研究与开发,2000(2),1-6。
[2]中华人民共和国交通部,《海港水文规范》[S],北京:人民交通出版社,2000。
[3]侍茂崇、陈春华、黄方、叶安乐,《琼州海峡冬末春初潮余流场特征》[J],海洋学报,1998,20(1):1-10。
[4]国家海洋局南海海洋调查技术中心,《琼州海峡跨海工程可行性研究基础资料 潮、流、悬沙调查报告》,1998。
[5]交通部第二航务工程勘察设计院《海南马村港总体布局规划》,1994。
[6]水利电力部华东电力设计院,《海口火电厂2×125MW机组工程设计报告 水文气象报告》,1988。
[7]陈上及、马继瑞,《海洋数据处理分析方法及其应用》[S],北京:海洋出版社,1991.
[8]国家海洋局、国家测绘局,《中国海岸带和海涂资源综合调查图集 广东省粤西分册、海南岛分册》,1989。
[9]《广东省海岸带和海涂资源综合调查报告》,海洋出版社,1998。
[10]地矿部第二海洋地质调查人队、国家海洋局南海分局,《琼州海峡西部天然气管道选线工程补充勘察报告》,1986年3月。
[11]国家电力公司中南电力设计院,《南方电网与海南电网联网工程可行性研究报告》,第一卷“总论”和第四卷“规划选线报告”,2003年3月。
[12]国家海洋局南海海洋工程勘察与环境研究院,《南方电网与海南电网联网工程琼州海峡海底电缆路由桌面研究报告》,2003年6月。
[13]海南省海洋开发规划研究院,《粤海铁路工程琼州海峡海底光缆路由桌面研究报告》,2001年10月。
[14]青岛海洋工程勘察设计研究院,《中国联通徐闻-海口海底光缆路由桌面研究报告》,2001年8月。
[15]地矿部第二海洋地质调查大队,《琼州海峡跨海工程地球物理调查报告》,1995。
[16]金波等,“琼州海峡东、西口地貌特征及其成因初探”,《海洋地质研究》VOL.2,NO.4,地质出版社,1982。
[17]彭学超,“琼州海峡地质构造特征及成因分析”,《南海地质研究》,地质出版社,2000年12月。
[18]李少英、宋运法、蔡树群、王盛安,《琼州海峡的流、浪、潮要述》,[J],南海研究与开发,2000(2),1-6。