Research on Horizontal Directional Drilling Scheme for Large Cross Section Submarine Cable Crossing Hard Rock

¹ State Grid Fujian Electric Power CO., Ltd. Fuzhou, Fujian, 350003, China
² Economic and Technological Research Institute, State Grid Fujian Electric Power Co., Ltd., Fuzhou 350000, Fujian, China
³ State Grid Quanzhou Electric Power Supply Co. Ltd., Quanzhou 362000, China
⁴ POWERCHINA Fujian Electric Power Engineering Co., Ltd., Fuzhou 350003, China

^* Corresponding author’s email: chenxx919@126.com

Abstract

With the increasing number of submarine cable projects, the terrain and geological conditions of the landing section are becoming increasingly complex, and the traditional implementation of trench burial is becoming increasingly difficult. A landing construction plan for large-section power cables suitable for steep terrain and rugged rock formations is studied and proposed based on sorting out existing submarine cable landing plans. Using directional drilling construction machinery ideal for rock formations, natural cable protection pipes are formed in rock formations after dragging and expanding the holes, meeting submarine cable protection’s safety and economic requirements. In the climbing section of the submarine cable from the seabed to the rock hole, measures such as bottom sandbag raising and top rock throwing security are adopted to avoid vortex-induced vibration and erosion caused by the cable hanging in the climbing section. The construction plan of the directional drilling passage through hard rock and the construction and protection plan of the submarine cable do not affect the current situation of the existing coastal reefs and can effectively protect the submarine cable from external damage, achieving green and environmentally friendly construction.