Abstract:It is of great significance for the harbor layout and construction to master the wave height distribution characteristics in the harbor，while the physical modeling process is expensive and complicated.Most numerical simulations only consider the influence of waves propagating through the breakwater entrance and ignore the overtopping effect.To address these limitations，this paper establishes a three-dimensional numerical wave pool for a encircled vertical breakwater based on the open source software OpenFOAM，and compares the numerical calculation results in the case of overtopping and non-overtopping with the experimental results to verify the accuracy of the numerical model.The results show that the model can simulate the overtopping process at the top of the breakwater and the wave height distribution in the harbor well，and can be used for further research on the optimization of harbor layout.

Abstract:Compared with traditional breakwaters，floating breakwaters have been widely developed because of their advantages such as convenient installation，water quality exchange，construction in various environments and mobility.Smooth particle hydrodynamics (SPH) method is used to study the interaction between regular wave and floating breakwaters.Firstly，the convergence of particle spacing is analyzed based on a regular wave propagation example in an empty water tank.Then，the interaction between regular waves and single and double floating bodies is simulated based on the verified water tank model，and the waveforms in front and back of floating bodies，the movement of floating bodies and the velocity field near floating bodies are analyzed.The results show that the double floating breakwater can significantly improve the wave absorbing performance compared with the single floating breakwater.

Abstract:The vertical revetment is a commonly used structural form in coastal engineering.There are numerous factors affecting wave overtopping under wave action，especially considering the actual multi-directional wave action，and currently，there is no unified calculation method.This paper utilizes the advantages of neural network methods in regression problems and constructs a BP neural network model.By using physical experimental data to build the training set，a predictive model for wave overtopping of sloping revetments under multidirectional wave action is established.Through comparisons with the test set，empirical formulas，and other experimental results，the model demonstrates excellent prediction accuracy and can satisfy engineering design needs.Furthermore，the model is utilized to analyze the influence of wave incident angle and directional spreading on wave overtopping，addressing the issue of indistinct variations caused by incomplete experimental data

Abstract:To investigate the fracture mechanical properties of dredged sand concrete，three-point bending fracture tests are carried out on the concrete specimens with different dredged sand replacement rates(0%，12.5%，25%，37.5%，50%).The whole fracture process of concrete is monitored with acoustic emission technology.The Weibull distribution damage model based on acoustic emission event is built，and the variation rules of model parameters are analyzed.The results show that with the increase of dredged sand content，the initial and unstable fracture toughnesses decrease firstly and then increase.The acoustic emission ringing count and energy reflect the three stages of fracture failure process of dredged sand concrete.With the increasing of dredged sand content，the accumulated acoustic emission count and energy increase.With the increasing of the dredged sand content，the brittle of concrete increases，the damage accumulation rate increases and the displacement corresponding to initial damage of the concrete decreases.

Abstract:The durability life prediction of the reinforced concrete structure of the existing wharf is faced with the problems of few available analysis parameters，low degree of fit，and doubtful prediction results.We obtain the distribution value of chloride ion concentration in the concrete core sample through on-site sampling tests.Based on the modified chloride ion diffusion model，we carry out the regression analysis using Matlab software to obtain the chloride ion diffusion coefficient，attenuation coefficient，surface chloride ion concentration and other parameters of the test piece，and predict the durability life of the breast wall reinforced concrete structure of the existing wharf.The results show that the prediction results of the parameter setting method are too large，and the prediction results based on the failure probability prediction method are basically consistent with the calculation results of the standard method，which is more consistent with the engineering practice.

Abstract:The service environment of high-pile terminals is complex，and the safety problem of structural displacement under variable loads such as ships and portal cranes is prominent.However，dynamic displacement monitoring is a challenge when high-pile terminals often do not have a reference frame and service is the norm in harsh offshore conditions.In this paper，the dynamic displacement monitoring technology without reference is used to monitor the real-time displacement of a high-pile terminal in Jiangsu.The displacement response law of the terminal under the condition of portal crane operation and ship impact is analyzed in detail，and a two-level early warning index of the terminal is proposed based on the applicability and safety of the terminal.Combined with numerical simulation calculation，the berthing suggestions of ships of different tonnage of the terminal are proposed.It is concluded that the operating position of the portal crane is a direct factor affecting the displacement response of the terminal.Under the influence of ship impact，the displacement response of A2 monitoring point is large in the X and Y directions due to the influence of boundary conditions such as approach bridges.The first-level early warning index is calculated from the maximum value of the main load action combination of the terminal，and the displacement response value is 15.39 mm；The secondary warning index is judged by the tensile limit stress value of concrete，and the displacement response value is 19.14 mm.The normal speed of 10,000-ton ships should not exceed 0.19 m/s when berthing，and the normal speed of 5,000-ton ships should not exceed 0.22 m/s when berthing.

Abstract:The Yushan green petrochemical base in Zhoushan is an important component of China's seven major petrochemical bases，and also the first petrochemical base to build a green development benchmark in the country.The construction of liquefied natural gas (LNG) terminal is very important for the development of the base.We explore the advantages of water areas to reasonably set up the movement safety zone for LNG ships as 1 n mile in front，0.5 n miles behind，and 300 meters in each side，reserve a 360 meters wide channel for opposing ships，and solve the problem of opposing containment during the navigation process of LNG ships.By using the substitution method，we conduct a quantitative analysis on the number of ships that need to be coordinated and avoided during the entry and exit process of LNG ships，vividly depicting the traffic scene after the construction of the LNG terminal.Through three-dimensional modeling of the Daishan North Channel Bridge on the Shanghai-Ningbo Channel，LNG ships，and surrounding water areas，we use maneuvering test methods，and propose that the safety distance requirements for the turning point of the LNG dedicated channel and the cross sea bridge should not be less than 6 times the length of the ship.

Abstract:As an important indicator of coastal resource planning and utilization management，the utilization efficiency of the Yangtze River main port lacks a clear and scientific unified definition at present.Based on the channel characteristics of different sections of the Yangtze River trunk line and a large number of current terminal design and operational production surveys，the paper makes reasonable adjustments to the parameter values in the formula for terminal design throughput capacity specifications，calculates reasonable throughput capacities for different cargo types and tonnage-level berths along the Yangtze River trunk line，and proposes the concept of unit shoreline accounting passing capacity as a quantitative standard for unit shoreline utilization efficiency.The research results can provide important technical indicators for the Yangtze River trunk line port planning，shoreline management，and terminal design.

Abstract:With the introduction of the “carbon peak and neutrality” in the 14th Five-Year Plan，China's infrastructure construction is driven towards a green and low-carbon direction，and the life cycle assessment(LCA)method is gradually being applied to China's construction industry as a comprehensive environmental impact assessment tool.Based on the life cycle assessment theory，we select an inland river port project in the upper reaches of the Yangtze River as the research object，and divide the whole life cycle of the port project into the construction phase，operation and maintenance phase and decommissioning phase to analyze the carbon emission sources and estimate the carbon emission.The results show that the life-cycle carbon emissions of the port project are 86,700 t CO2-eq，with 39.4%，56.7% and 3.9% for the construction，operation and maintenance and decommissioning phases respectively.The 95% confidence interval for unit carbon emissions is 651.92 to 745.21 kg CO2-eq/m2，with a median value of 698.14 kg CO2-eq/m2.The uncertainty in the inventory data is little，and the sensitive factors for port carbon emissions are concrete and electricity.The carbon emission evaluation results are generally good，and can be used as a relevant basis for the subsequent formulation of carbon emission reduction policies.

Abstract:In response to the problem of the lack of theoretical formulae for calculating the wave overtopping impact force on a building behind the breakwater，combining with the two-dimensional physical model test results of a Mediterranean petroleum jetty expansion project，we propose four calculation methods of average wave pressure acting on the buildings behind the breakwater based on the pressure sensors' data，and compare and analyze the results of the total force sensor with the calculation results of various methods.The results show that the high kinetic energy of the wave overtopping drops causes the measurement results of individual pressure sensors to be higher than those of the total force sensor. When the test equipment is limited，the total wave pressure on the building can be approximately calculated by taking the average positive wave pressure value based on synchronous data from uniformly distributing pressure sensors.Different strategies for calculating the average wave pressure have an impact on the magnitude of the total horizontal force，the average wave pressure calculated based on all measurement data is more reasonable，and the total horizontal force obtained by adopting this calculation strategy is closest to the total force sensor's results.

Abstract:Peat soil is difficult to consolidate and seriously endangers engineering safety because of its high organic content，high water content，high compressibility，low strength and slow consolidation.Relying on the expansion project of an overseas existing steel sheet pile wharf，this paper draws up a variety of reconstruction and expansion plans and structural plans in view of its outstanding characteristics such as deep peaty soil soft foundation，small yard area，serious structural damage of the old wharf，limited renovation space，and operation in construction stage.The advantages and disadvantages of each scheme are analyzed from the aspects of wharf operation，structural reliability，economy and construction difficulty，and finally the recommended scheme is proposed to adapt to the old wharf reconstruction and expansion project under the condition of deep peat soil soft foundation.Besides,the key technical difficulties and precautions in the construction process are analyzed，which can provide reference for similar projects.

Abstract:To meet the needs of water transportation，solve the problems such as difficult navigation conditions caused by the river section topography and river-related buildings in the entrance area of the ship lock approach channel，and ensure the safe passage of ships，this paper takes Shushan water conservancy project in Fu River as an example，and uses numerical simulation method to calculate and analyze the navigation conditions of the entrance area of the upstream approach channel of the lock.Aiming at the problem of bad flow pattern，the optimization scheme and measures are proposed，and the navigation conditions of the hub before and after the scheme are compared and analyzed.The research shows that the measures such as adjusting the plane layout of the lock are effective in improving the navigation conditions of the entrance area of the upper approach channel of the lock in the design stage.The research results can provide technical support for the navigation of Shushan water conservancy project in Fu River and other similar river section projects.

Abstract:The working valve is the throat of the filling and emptying system of the ship lock，and its performance directly affects the safe and efficient operation of the ship lock.In this paper，a whole three-dimensional mathematical model of the filling and emptying system and a partial three-dimensional mathematical model near the valve are established based on the Liujiang Honghua second line ship lock project.By comparing the water level within the lock chamber，the filling flow rate and unsteady pressure process after the valve，it is shown that the whole three-dimensional model can better simulate the culvert pressure change process after the valve compared with the results of the partial three-dimensional model calculation.The calculation is carried out for the continuous opening of the bilateral valves and the continuous opening of the unilateral valve in the water filling process.It is found that there is no negative pressure at the top of the culvert after the valve under the most unfavourable working conditions to meet the design filling time.The calculation method can be used as a reference for numerical simulation of ship lock valve hydraulics，and the simulation results can provide technical support for safe operation of the similar projects.

Abstract:The prototype observation study is carried out for the valve section cavitation problem of the ship lock，taking the newly built Xijin Second Line Ship Lock as an example，the observation shows that the valve slit type recommended by the valve model at the design stage is adopted for the water filling and draining valve，and the natural ventilation of the valve slit is realized in the prototype，and the maximum ventilation volume for the bilateral opening of the water filling and draining valve is 0.11 and 0.17 m3/s respectively.The effect of valve slit ventilation to suppress the valve section cavitation is remarkable：throughout the during the valve opening stage，the obvious cavitation bubble collapse sound and thundering sound which existed without ventilation are not heard at the top of the gate.Compared with no ventilation，the cavitation noise intensity during the bilateral opening of the valve is reduced by 60% and 82% on average after the valve slit is ventilated.The average noise collected by the sound level meter at the top of the gate during the valve opening process wis 68 and 79 dB respectively.The vibration of the valve boom is significantly reduced after the valve slit is ventilated.The anti-cavitation measures can effectively protect the valve and the valve section corridor from cavitation and ensure the safe and efficient operation of the lock.

Abstract:With the improvement of the navigation capacity of the Three Gorges and Gezhouba junction，the channel between the two dams is still the bottleneck that restricts the development of the Yangtze River shipping，and the Shipai bend section is one of the main obstructing sections.Aiming at solving the navigational obstruction problem of the Shipai bend，three-dimensional numerical simulation as well as prototype observation are adopted to carry out methods of diversionary and navigational tunnel.The results show that due to the small surface slope and low flow velocity at the entrance and outlet of the diversion tunnel of the bend waterway in a deep reservoir，the drainage capacity is extremely limited，the diversion results and the improvement of navigational conditions can't be achieved as expected.By using the tunnel navigation mode，the hydraulic index basically meets the standard requirements and can effectively improve the navigation efficiency.The research results can provide theoretical support and technical reference for improvement of sharp bends navigability in a deep reservoir.

Abstract:The opening time of ship lock valves has an impact on the navigation efficiency of the lock chamber，the pressure of the water conveyance gallery，and the berthing conditions of the lock chamber.To optimize the operation mode of the valves，physical model tests are used to analyze the factors such as the water level of the ship lock inlet，the pressure characteristics of the water passage，the ship mooring force in the lock chamber and the downstream channel.The results show that the mooring force of ship in front transverse，rear transverse and longitudinal direction decreases with the increase of valve opening time，and the mooring force of ship in longitudinal direction is greater than that of ship in transverse direction.With the increase of the opening time of the valve，the pressure in the passage gallery decreases first and then increases during water filling，while gradually increases during water discharge.It is considered that the overall operation effect of the ship lock is better when the valve opening time is 6 min.The conclusion can provide technical support for engineering practice.

Abstract:The waters of the Yangtze River estuary are characterised by a large number of channels and complex changes in river conditions.To analyse the changes in hydrology of the south channels and north passage of the Yangtze River estuary under the action of runoff currents，and further improve the understanding of the south channels and north passage of the Yangtze River estuary，statistical comparative analyses are conducted on the hydrological characteristics based on the hydrographic data of the flood and dry season at each measured station in the Yangtze River estuary from 2018 to 2022.The research results show that the impact of runoff and tidal current changes on the hydrological features of the south channels and north passage of the Yangtze River estuary are different，and the upward and downward flows of the waters are influenced by the coupling effect of runoff and tidal current at the same time.The critical point of the influence of the runoff tide in the south channels and north passage is around the upper mouth of the north passage.The critical position oscillates with the change of the runoff and tide，and the position of the salt water wedge and the maximum turbidity zone also oscillates up and down with the change of the runoff and tide.This oscillation also causes the change of the silt return distribution.

Abstract:The revetment project is widely used to resist the erosion of water flow and maintain the stability of the bank in the channel regulation project.It is usually arranged in the bank slope which is prone to collapse so it is vulnerable to water erosion，which is affecting its normal function.In this paper，the measured data are used to analyze the damage of Caijiadu revetment in Xinzhou—Jiujiang reach of the middle reach of the Yangtze River.The results show that the head of Caijiadu underwater revetment is seriously damaged，and the collapse nest on the upstream side becomes larger.The main reasons for the damage are the water flow attaching to the bank and swinging of the major stream channel.On this basis，the necessity of maintenance is analyzed，and the maintenance method of “repairing slope+stabilizing toe” is proposed，which can provide reference for similar revetment in the middle and lower reaches of the Yangtze River.

Abstract:This paper takes the waiting anchorage of the Babao ship lock on the second channel of Beijing-Hangzhou Grand Canal as the research object.Based on previous achievements such as traffic volume prediction，analysis of navigation conditions and operational characteristics of Babao ship lock，this paper uses empirical formula and queuing model to analyze and calculate the appropriate anchorage capacity，makes an example comparison using the layout of the waiting anchorage of Sanbao ship lock，and proposes targeted transformation measures.The results show that the appropriate capacity of the waiting anchorage is no less than the number of ships in three lock times.It is recommended to set up a remote dispatch anchorage for cascade dispatch.

Abstract:Affected by Minjiang River and Hengjiang River，the water level variation characteristics of Shuifu-Yibin section in the lower reaches of Xiangjiaba are complex.The water level and flow data between the main and branch streams belong to multi-dimensional spatio-temporal data.The study selects spectral temporal graph neural network (StemGNN) for multi station water level prediction in the downstream of Xiangjiaba.The results show that the method is suitable for multi station water level prediction in the study area，and the prediction performance of the model in the next 1 hour and next 8 hours is better.The maximum prediction error at Xiangjiaba station，Yibin station and Lizhuang station is about 0.5 m.The characteristics of StemGNN are that it can automatically extract the river network structure information from the input data，reflecting the confluence characteristics of the study area.Hengjiang River flow has little impact on the water level and flow in the study area；Xiangjiaba reservoir water level，Hengjiang water level and Gaochang water level represent the early stage water level of the study area.Gaochang flow，as a large flow input，has a great impact on the water level and flow of the study area.The research results can provide new ideas for multi station water level prediction in the river reach with complex water level variation characteristics，such as near dam section and tributary inflow.

Abstract:The turbulent characteristics of the water flow in branch reach has an important influence on the change of the riverbed and the fish habitat，and the existing research on the turbulent characteristics of the horizontal distribution of the water flow in the branch reach is lacking.In order to clarify the turbulent characteristics of water flow in the branch reaches，we take the prototype of the upper reaches of the Yangtze River，carry out the generalized model test，and study distribution characteristics of three directions (longitudinal，transverse and vertical) time average velocity，turbulent strength and turbulent kinetic energy of water flow at different depths.The results show that there are low flow rates in the diversion and confluence area，where the water flow is strong.The turbulent strength of the flow at different depths is positively correlated with the horizontal section area of the beach body and negatively correlated with the distance from the riverbed.The strong turbulent area of the near bottom flow is dispersed.The strong turbulent area of the upper flow is concentrated.

Abstract:The river reaches from Kangtan to Yingpantan in Zhongwei of Ningxia，the mainstream of the Yellow River，is about 9 km long，wide and narrow in plan，and has the shape of a lotus root joint.Considering the problems of channel curvature，bifurcations，unknown channel，violent turbulence in the river reaches from Kangtan to Yingpantan，we use the river model test to analyze and research the effect of channel regulation by dredging the shallow area and widening the channel，and optimize the design scheme according to the test results.It is found that the bending radius of the newly opened fairway at Zhongning Bridge beach is more than 550 m and the upstream and downstream fairways are smoothly connected with each other，and at Taiping beach，the rehabilitation measures of dredging，impoundment and slot filling are carried out，which can effectively improve the flow conditions and ensure the safety of navigation.

Abstract:Changjiang Shipping Engineering Survey and Design Institute，Chongqing 401147,China）

Abstract:The coal piles stacked in the open yard are the main source of dust pollution in the coal terminal.The implementation of dust suppression for each coal pile in the current port management relies on experience and the characteristics of the dust generation area are not fully considered，resulting in poor dust suppression or wasted resources.Therefore，a quantitative study of fugitive dust diffusion in open yards at coal terminals considering changes in external influences is carried out in this paper.Taking a coal export terminal yard in northern China as an example，multiple combinations of experimental conditions at different wind speeds and various wind incidence angles (0°，45°，90°) are considered.A numerical simulation of the dust diffusion in each pile is carried out using computational fluid dynamics (CFD) software to visualize the specific areas of dust emission and to calculate the amount of dust emissions on the surface of the piles.The characteristics of dust emissions from coal piles at different locations are analyzed specifically providing a theoretical reference for dust suppression operations in the corresponding yard conditions.

Abstract:With the development of unmanned aerial vehicle and digital image processing technology，surface disease recognition methods based on computer vision have been widely used in bridges and roads because of their safety and rapidity.However，due to the complexity of images，it is challenging to achieve accurate segmentation and quantitative analysis of wharf apparent diseases by current methods.This paper proposes a method for segmentation and quantitative calculation of wharf surface spalling disease regions based on zero-shot deep learning model SAM (Segment Anything Model) and image transmission transformation correction.SAM can effectively overcome the problems of concrete spalling images such as background noise，small gray difference and so on，thus being more accurate and less sensitive by noise.Further，the quantitative calculation of key geometric features of spalling diseases is realized through image processing operations such as correction，denoising and conversion.The experiments based on laboratory model and field images show that the new method has strong generalization ability and high accuracy，and can realize the accurate and rapid recognition of wharf concrete surface diseases and has a wide application prospect.

Abstract:To the problems of high safety risk coefficient，high personnel control requirements，high installation difficulty，and tight schedule in the construction of LNG (liquefied natural gas) terminal engineering，research and application based on BIM and Internet of things technology on the intelligent construction site platform have been carried out.By adopting the intelligent site management method that integrates BIM technology and internet of things technology，we deepen the creation of construction BIM model，and combine the corresponding intelligent equipment to realize the application of model and on-site data access and integration，which solves the problems in the construction process of typical LNG terminal projects，such as difficult control during construction，multiple data information sources integration，and difficult on-site management of labor personnel.By integrating BIM technology with intelligent construction platforms during the construction phase，the construction quality and technical management level of LNG terminal construction projects have been effectively improved.The significance of this study lies to provide useful experience and reference for the construction of LNG terminals，and promote the application and development of intelligent construction site platforms in this field.

Abstract:To analyze the effect of container twist lock station layout technology on the handling operation efficiency in automated container terminal using single trolley quay cranes，three terminal simulation models with different twist lock station layout technology are established by FlexSim software.The working efficiency of terminal handling equipment，the average distance per cycle and speed of horizontal transportation equipment in different models are compared by simulation tests.Simulation results show that the handling operation efficiency of the twist lock station parallel layout process plan is increased by 1% to 13% compared to the single trolley quay crane with twist lock handling platform process plan.The handling operation efficiency of the twist lock station vertical layout process plan is increased by 12% to 14% compared to the twist lock station parallel layout process plan.The simulation results can provide theoretical support for the design of automated container terminals or the upgrading and renovation of traditional container terminals.

Abstract:Deep cement mixing pile is a common method for reinforcing soft foundations.It has been used on land in China and a perfect quality evaluation system has been established.In recent years，China's water transportation engineering has developed towards large-scale，deep-water and high-quality development，and the underwater DCM technology has been successfully applied to multiple major projects.Due to the significant differences in equipment，technology，and environmental conditions between underwater and land construction using DCM methods，directly applying land-based evaluation methods to underwater operations may not be effective.This paper compares and analyzes the relevant regulations on DCM quality evaluation in China，Japan，the United States and Europe，the results show that when the detection quantity of underwater DCM is large，the data follows a normal distribution，Japanese standards can be used for evaluation.The minimum average strength is used as the representative value of pile strength in the domestic JGJ 340—2015 Technical Code for Testing of Building Foundation.However，due to the large diameter of underwater DCM piles，the testing samples are relatively small and the statistical significance is not obvious，so it is not suitable for evaluating the quality of underwater DCM composite foundation.

Abstract:In response to the scientific compilation of the adhesion test method in JTS/T 247-2023 Regulations for Soil Testing in Water Transport Engineering，we carry out targeted exploratory tests through thorough research and investigation of the relevant clauses in the previous specifications，starting from the development of test plans，customization of test equipment such as soil sample cups，pressure plates，and protective rings.By using a single variable analysis method，we study the effects of soil sample cup size，pressing plate size，and retaining ring thickness on soil adhesion testing，summarize a more practical，operable，and in line with the provisions of soil adhesion testing methods in the water transportation engineering industry，and include provisions in the section of JTS/T 247-2023 Regulations for Soil Testing in Water Transport Engineering，promoting the optimization and improvement of soil adhesion testing methods in the water transportation engineering industry.

Abstract:In dredging engineering，determination of optimal velocity of slurry transportation usually depends on empirical formulae.Changeable working conditions lead to low prediction accuracy.This paper uses Durand model to model the resistance loss under different test conditions，and adjusts the model constants based on test data to improve prediction accuracy of Durand model.The paper uses Gaussian process regression method in the modelling，with analysis of influence of training samples numbers on prediction results.The paper proposes a velocity optimization method based on resistance-velocity model，and carries out comparative tests.The results show that prediction accuracy of pipeline resistance model established by Gaussian process regression method is higher，which can be higher than 0.97.Critical velocity can also be real-time updated in terms of changes of pipeline resistance (concentration)，providing a more effective optimization method to determine the optimal slurry velocity.

Abstract:Aiming at the problems that underwater drilling construction of hydraulic hammer can not be visualized and construction parameters are difficult to determine，ABAQUS simulation platform is used to simulate underwater hydraulic hammer drilling，and the design of drilling construction parameters is theoretically studied.The impact energy of different types of hammer has a great influence on the drilling speed.To obtain the ideal construction efficiency，the hammer type should be selected according to the rock parameters.It is found that the splitting effect in two directions is produced under the condition of three free faces.With a small increase in the spacing of drilling holes，the penetrating depth does not change，but the depth produced by the splitting effect changes greatly.when the requirement of the channel dredging smoothness is high，the construction efficiency and quality can achieve the ideal effect by selecting the hole layout parameters corresponding to the depth of penetration and the depth of the splitting effect.

Abstract:High-frequency breaker is a new type of reef removal technology that meets the requirements of ecological waterway remediation.To explore the gouging law of high-frequency breaker reef clearing，the high-frequency breaker gouging model test is conducted，and the gouging depth is taken as the measurement standard of rock breaking efficiency.The law of the change of drill rod gouging depth with time is studied，and the influence relationship of different rock mass strength and different working gears on the gouging depth is analyzed.Based on this，the empirical formulas of gouging depth，chiseling time and rock mass strength under different working conditions are fitted.The results show that the chiseling depth has a nonlinear positive growth relationship with the chiseling time，and the increase amplitude decreases with the increase of time.The gouging depth decreases with the increase of rock mass strength.The gouging efficiency increases with the increase of the working gear，with gear 3 being the optimal working gear.