"Geotechnical engineering is a comprehensive applied science to meet the needs of engineering construction, find out the relationship between engineering construction and the natural environment through geological survey, engineering survey, etc., and solve the problems of geotechnical and underground engineering. It is characterized by high concealment, large regional differences, and strong uncertainty. As an" underground worker "who has been engaged in geotechnical and underground engineering for a long time, Insist on being realistic and pragmatic, continue to explore the integrated and innovative development of geological engineering, geotechnical engineering and structural engineering, provide solid theoretical guarantee and technical support for geotechnical and underground space engineering construction and environmental protection, and promote high-quality and sustainable development and utilization of underground space. "
Guests interviewed in this issue:
Huang Junguang Guangdong Provincial Engineering Survey and Design Master, Deputy Chief Engineer of Guangzhou Design Institute Group Co., Ltd
Indissoluble bond with civil engineering
I am a Hakka from Zijin County, Guangdong Province. I am deeply influenced by the tradition of our Hakka people's worship of literature and education, loyalty to the country and filial piety. I always hope to be a teacher who preaches and teaches and dispels doubts, or a doctor who is devoted to filial piety and benevolence. Until I was admitted to Zijin Middle School, which was built near the mountain, the school buildings were mountain buildings with stacked steps and retreating platforms. I often ran back and forth in the mountain classroom and the stadium below the mountain, often climbing stairs, climbing over retaining walls, and jumping intercepting ditches. At that time, I often daydream about some more time-saving, lightweight and comfortable mountain building design schemes, It also inspired me to make a lot of more reasonable reconstruction ideas, such as bridge crossing, local staggered floor layout, integration design of retaining slope protection and main structure in some places: after in-depth study, I found that there was a lot of knowledge in all aspects, especially civil engineering knowledge, the more chewy, the more powerful, so I solemnly filled in the energy before the college entrance examination“ Fighting the Earth ”A big project.
In the summer of 1998, I received the admission notice of civil engineering (geotechnical) major from China University of Geosciences. As I grew up playing with mud in the mountainous countryside, I was puzzled by the suffix "rock and soil"“ Rational development and utilization of underground space is the best way for urban sustainable development in the 21st century ”"Rock and soil" is the main carrier of underground space, and suddenly it feels promising. After deeply contacting with geotechnical engineering, I gradually became attracted by a large number of unknowns and uncertainties in geotechnical engineering. It is also slowly discovered that engineers, especially geotechnical engineers, are just like doctors, who are loyal and filial to the cause of family and country construction by constantly solving difficult problems.
After graduation in 2002, I have been working in Guangzhou Design Institute Group Co., Ltd. (formerly: Guangzhou Design Institute) until now. Benefiting from the technical advantages accumulated by the design institute group platform, I have successively served as the chief engineer, deputy director and director (concurrently) of the municipal geotechnical design institute of Guangzhou Design Institute since 2010; Director of Geotechnical and Underground Engineering Institute, Director of Survey and Survey Institute (concurrently), Director of Housing Safety Appraisal Institute (concurrently), Deputy Chief Engineer of Design Institute Group (concurrently). In the past 20 years, from assistant engineer to professor level senior engineer, From the designer who overcame each project to the geotechnical technology leader who now leads the team to overcome difficulties, and then to the solid growth and transformation experience of being recognized as a survey and design master in Guangdong Province in 2022, we have a deeper understanding of engineers' hardships, their sense of achievement, and their mission and responsibility.
Our team, based on overcoming the difficulties of each project, through in-depth exploration and research and development of new directions and new technologies, Put forward a new route for the integration of geology, rock and soil and structure and the development of industry university research cooperation By fully authorizing and giving full play to the creativity of engineers, introducing doctors (later) to carry out technology research and development, deepening the cooperation between industry, university and research and other measures, the geotechnical engineering specialty can add luster to the Guangzhou Design Institute Group. In March 2022, the Design Institute Group established the Geotechnical and Underground Space Institute by integrating professional institutes below ± 0.000. I served as the first president. At present, there are more than 60 people in the Institute, including one survey and design master in Guangdong Province, one young reserve talent in Guangzhou, eight registered civil engineers (geotechnical), four first-class registered structural engineers, four professor level senior engineers, and ten doctors and postdoctors, With more than 30 masters, our institute has become an excellent team with strong comprehensive design strength in the direction of geotechnical and underground space in South China.
Since graduation, I have been focusing on the work related to geotechnical and underground engineering, mainly focusing on the following aspects:
(1) Foundation pit engineering design: The representative projects include Guangzhou Tower (600m), Guangzhou Commerce Center (350m), International Cultural Center (320m), Xian Village Lot 310 (330m), Zhuhai Center (330m), Pearl River City (303m) and other super deep and super large foundation pits; The north area of Huachenghui underground space in Pearl River New Town, the old reconstruction of Xian Village, Pazhou E-commerce District and other complex foundation pit groups.
(2) Slope engineering design: The representative projects include the large-scale geological disaster treatment of the back mountain slope of Linyu Villa in Huangpu, Guangzhou (known as "the first slope in South China", the maximum slope height is about 200m, and the treatment area is about 200000 m2), and the slope support project of the production and scientific research comprehensive base of China Southern Power Grid.
(3) Foundation design of complex geological foundation: Representative projects in areas with strong karst development include Baiyun Airport Phase III resettlement area, Guangzhou North Railway Station resettlement area, Guangzhou Baiyun District Shatinggang resettlement area, Huadu Rongchuang City, etc.
(4) Representative projects in soft soil areas: Zhuhai Chimelong Ocean Kingdom (the world's largest marine theme resort, with a foundation treatment area of 500000 m2), Lingshan Island Jianjiu nine-year school, and Nansha Hospital Project of Guangdong Provincial Hospital of Traditional Chinese Medicine.
(5) Anti floating design of underground structure: Representative projects include Guangzhou Port Huangsha New Aquatic Market Project (the largest aquatic market in Asia) and Guangzhou Chimelong Panda Hotel Project.
(6) Consultation and evaluation on vibration and noise reduction of rail transit: Representative consulting projects include Hejing Pearl River New Town Plot A4-3 Project, Guangzhou International Innovation City Phase I C Residential Plot Project, Guangzhou World Trade Plaza Project and other subway vibration and noise reduction assessment projects.
Guangzhou Tower is A landmark building in Guangzhou, with a building height of 600m, was the world's tallest tower at that time 。 I was lucky to participate in the steel structure design and foundation pit support design of the Guangzhou Tower project, and benefited a lot, The core design idea is also simple ——How to transfer the force to the foundation reliably and efficiently through the complex structure system.
The tower body of Guangzhou Tower is a composite structure of reinforced concrete core tube steel tube columns, which is composed of 454m tower and 146m mast. The facade and outer tube structure are composed of tapered tube steel inclined columns, rings and diagonal braces. The hollow and open structure reduces the weight of the tower body and the wind load it bears.
The perimeter of the foundation pit of Guangzhou Tower is 686m, and the maximum excavation depth is about 16.95m. The foundation pit is 65m away from the Pearl River in the north, and the surrounding environment is complex. 800mm thick underground diaphragm wall+two concrete ring truss internal support/reverse arch wall support is comprehensively used.
At present, we are lucky to continue to participate in the reverse design of the south square of the Guangzhou Tower, and fully integrate underground space resources around the Guangzhou Tower. When the project is completed, it will become a representative of the new generation of urban reception hall in Guangzhou.
2 Underground space in Huacheng Huibei District
Huachenghui is the "city living room" of Guangzhou It is an important part of the core area of Pearl River New Town on the new central axis of Guangzhou, and a large-scale underground building integrating transportation, commerce and entertainment; The underground space project in the north area is located in the north of Jinsui Road, the south of Huangpu Avenue, and between Zhujiang Avenue East Road and Zhujiang Avenue West Road. The excavation depth of foundation pit is 13.4~16.4m, and the excavation area is 61584m two The perimeter is 1496m. There are many high-rise buildings around, and the north and south are adjacent to the tunnel. APM subway and two main roads run through the foundation pit from below. During the implementation of the project, the protection of the metro APM line section tunnel, the support design of the junction between Huangpu Avenue and the tunnel running through the north side, and the support design of the Pearl River Avenue and pipeline protection are the top priorities. We The integration and application of geotechnical, structural, tunnel, bridge and other technologies has realized the normal operation of buildings and facilities around Pearl River New City during the foundation pit construction 。
Protection of metro APM line section tunnel: We Portal frame structure system with closely arranged hand dug piles and multi ribbed prestressed steel concrete beams The foundation pit with a north-south penetration length of about 380m shall be protected. The closely spaced piles are used to restrain the horizontal deformation of the tunnel in the APM section and bear the vertical load transferred from the upper main structure. The multi ribbed beams can restrain the vertical deformation of the tunnel and transfer the vertical load of the upper main structure to prevent the load of the basement structure from being transferred to the existing tunnel. Both of them serve as the main structure piles and transfer beams while restraining the deformation of the tunnel in the section.
The support design of the junction between Huangpu Avenue and the tunnel on the north side: The specific scheme of foundation pit support in this range is to first use advanced steel pipe grouting to reinforce the soil above the tunnel, and set the support grading platform in combination with the downward step platform of Huangpu Avenue pedestrian tunnel, and use closely spaced soil nails to reinforce, and set two pre-stressed anchor cables to strengthen the control of displacement, forming an in-situ self stabilizing composite retaining structure. The above soil nails and anchor cables avoid the protection range of tunnel shield, reduce the disturbance to existing tunnels, and ensure the normal use of Huangpu Avenue.
The support design of Zhujiang Avenue East Road and Zhujiang Avenue West Road across the scope of foundation pit has considered two major problems, one is to meet the requirements of foundation pit deformation and stability, and excavate the soil under the road, the other is to ensure the normal operation of Zhujiang Avenue during the construction of foundation pit, and finally adopt the structural form of internal support covered with steel temporary bridge 。 The internal support adopts the form of opposite support, and the plane layout is consistent with the direction of Pearl River Avenue. The horizontal spacing of the internal support is adjusted to bear the dead weight, lane load, etc. of the temporary steel temporary bridge. The vertical components are steel columns (cast-in-place pile foundation), which form a frame system with internal supports.
Now it seems that, Huacheng Huibei District Project is located in the core area of Pearl River New City, and the surrounding environment is very complex. It covers the subway station and nearly 200m interval tunnel, traverses two main roads, and is surrounded by super high-rise buildings and backbone tunnels. Once an accident occurs, the social impact will be very huge. Many experts feel very difficult and headache to complete the foundation pit in a short time 。 I repeatedly searched the site, checked and rechecked the calculation and simulated the drill of major control nodes throughout the process, and finally our economical, applicable and efficient construction design scheme successfully passed the test of each major node, ensuring that the foundation pit was implemented on time according to the quality, and at the same time ensuring the normal order of the society, which won valuable time for building Guangzhou's "urban living room" to meet the Asian Games.
3 Foundation pit group of Pazhou E-commerce District
Pazhou E-commerce District Located in Haizhu District, Guangzhou, with a total land area of 158.9 hectares and a total building area of 4.734 million meters two 。 As an Internet innovation cluster in South China, it includes Fosun, Alibaba, Vipshop, Xiaomi and other South China headquarters 。 The foundation pit group of Pazhou E-commerce District is close to the Pearl River, and there are deep silt and sand layers. The groundwater is greatly affected by the tide. The basements of each plot are mostly 4-5 floors. The depth of the foundation pit is large, and the excavation sequence is uncertain. The construction interaction, time and space effects are significant, and the construction risk is high. In addition, there are many investment subjects of the project, belonging to different competent departments, and the development progress is different. The overall construction progress is affected by the factors such as the approval time of each project, funds, and the owner's planning.
The foundation pit group of Pazhou E-commerce District adopts the construction mode of independent construction of each construction subject and combined construction of a few plots, such as Vipshop, Global Market, Kangmei Pharmaceutical and iFLYTEK 。 The water stop and support system of each sub foundation pit in the foundation pit group shall be designed in coordination as a whole, the vertical support system shall be as flush as possible, and the removal and replacement of the support shall be coordinated to ensure that the force transmission path is smooth and the deformation can be controlled. During the construction of each sub foundation pit, the space-time effect shall be fully utilized, and the information construction dynamic adjustment design shall be made to ensure the overall construction safety.
In particular, Guangshang Center and Southern Media are both foundation pits of super high-rise buildings with a height of more than 300 meters. Between the two foundation pits is the high-speed subway foundation pit (about 30 meters deep) of Guangzhou Metro Line 18 under construction. According to the development sequence, the construction sequence of these three foundation pits is Guangshang Center first, followed by the simultaneous construction of Line 18 and South Media Foundation Pit, which makes The three foundation pits show a typical situation of asynchronous excavation, support removal, main body construction and backfilling, and the surrounding subway has high requirements for construction deformation control 。 For this working condition, we mainly take the following measures in the design scheme: 1） The diaphragm wall is thickened, and the limited soil mass between pits is reinforced with mixing piles to effectively control the deformation caused by eccentric pressure; 2） The supporting height of the three foundation pits is basically the same to ensure the coordination of force transmission; 3） The bending and shear resistance of the retaining structure under the most unfavorable working conditions shall be checked and calculated when the support is removed or replaced at different times.
▲ Real picture of support of pit three adjacent to working condition
▲ Typical sectional drawing of three pits adjacent to working conditions
In fact, the most difficult feeling of foundation pit design is the design of foundation pit group. Through the actual engineering experience, there are several experiences: 1） The key and difficult points of foundation pit group design can be roughly divided into two levels: theoretical technology and working condition control. The theoretical technology is mainly aimed at "pit group effect", and the working condition control is divided into time control, space control and coordination management. 2） The force transmission path of the support system should be clear, the overall layout of the support should be coordinated and unified with the local deep layout, and the supports on both sides of the partition wall should be set at the same elevation as far as possible; The process of removing and replacing supports of adjacent foundation pits should be balanced and symmetrical, and the time and sequence of removal or chiseling should be clear; The temporary partition should be chiseled off in sections and sections, and the plate supports on both sides should be butted back to the top in time. 3） The independent implementation mode of the plot, the construction is relatively independent, the mutual restriction is small, the construction is convenient, and the construction progress is fast, but the required temporary structures are many, and the cost is high; In the implementation mode of land consolidation, the cost of supporting structure materials is reduced, but the overall construction period and land development progress are slow.
Over the years, I have participated in nearly 1000 foundation pit design and consultation, reviewed more than 2000 foundation pits, and also made a lot of experience summary. In my spare time, I published the monographs "Deep and Large Foundation Pit Engineering Technology" and "Technical Demonstration and Emergency Rescue Application Research of Foundation Pit Engineering Design Scheme", which also won the nickname of "King of Pit" by accident 。
4. Houshan Slope of Linyu Villa, Huangpu District, Guangzhou
The project of Linyu Villa in Huangpu District, Guangzhou is known as“ The first slope in South China ”It covers almost all slope disasters in South China. In addition to bearing the technical challenges of design and construction, Still under the great pressure of "positive" attention from the society 。 This project is also a rare one that has made me sleep and eat uneasily in the past 20 years.
On June 8, 2018, under the influence of rainfall, three boulders (the largest one with a dead weight of more than 70 tons) fell down from the back hill of Building 6 and Building 8, Linhui Street, North Chuangye Avenue, Huangpu District, Guangzhou, causing serious impact damage to the residential buildings of Poly Linyu Villa Community. According to the survey, the project is located in the northwest side of Sianggang Mountain, with an elevation of 292.78m. The rock mass of Sianggang Mountain has developed fissures and serious denudation, and the granite is spherically weathered. The surface layer is covered by residual slope deposits. The gully is scoured by water, exposing a large number of granite boulders, and granite boulders are also widely distributed on the hillside. The survey revealed that 3706 boulders may continue to slide.
Full investigation and identification of geological disasters not only highlight the problem of boulders, but also many problems such as water and soil loss, landslides, collapses, dangerous rocks, deep alluvial rock piles, etc. After comprehensive analysis and demonstration, combined with the principle of information design, we put forward a comprehensive management and protection system scheme for multiple defense lines: multiple intercepting and drainage systems, different measures are taken to control landslides, boulders and dangerous rocks according to different disasters, active and passive protective nets and multi-layer protection for rockfall grooves, and slope cutting platforms are used as construction channels and daily operation and maintenance channels, Comprehensive control measures such as three-dimensional greening protection.
Finally, through the concerted efforts of the team, we overcame the problem of this huge complex system problem project, put forward many engineering invention, improvement, and integration of science and technology programs, and successfully applied for one science and technology project from the Ministry of Housing and Urban Rural Development of the People's Republic of China and one science and technology project from the Department of Housing and Urban Rural Development of Guangdong Province 。 The experience of this project not only tempered the team, but also stimulated our enthusiasm for research and development of complex slope treatment.
5 Huangsha New Aquatic Market
The project of Huangsha Aquatic Products New Market is located at Luowei Wharf in the east of the Ring Expressway in Liwan District, Guangzhou, bordering the Pearl River in the south and Guangzhou Ring Road in the north. The project includes four floors of ground structure and two floors of basement. The foundation pit area of the project is about 21400 m two The depth is about 11.8m, and the area of the basement adopting the water carrying floating reduction scheme is about 12000 m two 。
The sand layer of the project site is thick, the water level is high, and it is significantly affected by the tidal fluctuation of the Pearl River. To build a foundation pit in this water rich and strong permeable environment, it is necessary to focus on the bearing capacity of the stratum and the anti floating capacity of the structure. At the same time, considering that the structural load of the project is relatively low and the bearing capacity of the sand layer is relatively good, that is, the natural foundation can basically meet the bearing requirements of the structure, therefore, from the perspective of improving economic benefits and ensuring project safety, under the premise of taking into account the bearing capacity of the stratum, the reasonable solution of structural anti floating design is the top priority of the project.
Final innovative application Water carrying floatation reduction system The invention overcomes the defects of the existing passive anti floating technology, such as high cost, long time consuming and difficult to determine the design water level; It makes up for the shortcomings of the active anti floating technology, such as large pumping capacity, limited scope of action, occupying too many basements, and difficult to meet the requirements of civil air defense; The self control of anti floating water level is realized, and the applicable stratum conditions of anti floating technology are widened; Realize the purpose of using the building's own weight to resist the groundwater buoyancy, reduce the passive measures such as uplift pile anchor, bottom plate thickness reinforcement, reduce the project cost and duration, meet the requirements of safety, reliability and durability, and promote the development of anti floating technology in building engineering.
Practice public welfare with original intention
In July 2021, as the leader of the survey and design team for the technical investigation of accidents, he participated in the "7" project? 15 The investigation and handling of Zhuhai tunnel flooding accident took more than 20 days to successfully complete the rescue and accident investigation tasks, which was praised in writing by Guangdong Provincial Emergency Management Department. In addition, he participated in the rescue and relief work of many accidents, such as the ground collapse accident in the construction area of Shahe Station of Guangzhou Metro Line 11 in 2019, and the large-scale geological disaster at the back slope of Linyu Mountain Villa in Huangpu, Guangzhou in June 2018.
A lot of reinforcement work has been carried out in the protection of cultural relics, such as the Wuyang Stone Statue in Yuexiu Mountain, Zhongshan Monument, Shishi Church and other national cultural relics. Although many projects have little economic benefits However, as an engineer, I am always proud to make use of my professional skills to contribute to the protection of cultural relics 。
What are you busy with recently
I mainly do some design, consulting and R&D work around service projects in daily life to create more development space for the team. In recent years, I have also invested more energy in experience summary, scientific and technological innovation, academic exchanges, platform building and other aspects. It mainly includes the following aspects:
(1) Specification preparation: At present, I am busy editing two Guangdong provincial standards, Code for Geotechnical Engineering Investigation and Building Slope Engineering Technology. There are also many specifications, such as the Technical Code for Building in Soft Soil Areas, which are being edited.
(2) Monograph compilation: Two monographs, Deep and Large Foundation Pit Engineering Technology (published in 2022) and Building Foundation in Karst Area (published in 2021), have just been published.
(3) Scientific and technological innovation: Led the establishment of the Geotechnical and Underground Space Research Center and served as the director of the center. Led by 7 post doctors in the station, he undertook 2 projects of the National Natural Science Foundation of China, 1 project of the Ministry of Housing and Urban Rural Development, 1 project of the Provincial Department of Housing and Urban Rural Development, 4 scientific and technological projects of Guangzhou Construction Group, and 2 scientific and technological projects of the Design Institute Group. The annual average horizontal scientific research funding was more than 8 million yuan. Last year, our team applied for 15 patents, published 6 papers, and won 3 first prizes of the Provincial Association's Science and Technology Progress Award. The scientific research achievements were satisfactory.
(4) Platform construction and academic exchange: In 2021, it will hold the "High Quality Development Conference of Engineering Survey and Design in Guangdong Province and the founding conference of Geotechnical and Underground Engineering Branch". In July 2022, the seventh engineering oriented foundation technology exchange meeting was held. In September 2022, the "Preparatory Meeting for Underground Space Branch of Guangzhou Engineering Survey and Design Association" was held.
▲ On April 29, 2021, Guangdong Provincial High Quality Development Conference of Engineering Survey and Design and the Founding Conference of Geotechnical and Underground Engineering Branch (awarding the letter of appointment of president)
▲ On July 2, 2022, the seventh engineering oriented foundation technology exchange meeting will be held (Guangzhou venue)
▲ On September 6, 2022, the Preparatory Meeting of Underground Space Branch of Guangzhou Engineering Survey and Design Association was held
Thoughts on industry and specialty
// Some thoughts on the current situation and future of the industry
In recent two years, the real estate market has been depressed, and many employees have been shrouded in pessimism, especially young engineers who are confused about the future. Over the past 20 years, with the explosive development of infrastructure construction and the real estate market in China, the enrollment rate of related majors in colleges and universities is also quite amazing. In the case of today's shrinking market size, the industry is facing greater internal pressure. It is believed that after this market adjustment, the scale of talent output of colleges and universities will also be reduced, which is conducive to the long-term healthy development of the industry. From the perspective of the Guangdong Hong Kong Macao Greater Bay Area, the civil engineering market is still very large, especially the underground engineering still has great potential 。 For example, in September 2021, the General Office of the People's Government of Guangdong Province issued the "14th Five Year Plan" for the Development of Guangdong's Comprehensive Transportation System, which roughly estimated that the investment in major transportation infrastructure projects alone would exceed 2 trillion yuan, and civil engineering projects in civil construction, water conservancy and waterway industries would also be maintained at a large scale. However, it is difficult for the traditional construction market to reach another peak, but Considering the growing demand for green, smart and high-quality construction such as urban renewal, resilient cities, underground space, environmental rock and soil, smart construction, and dual carbon buildings, the construction industry is still very broad in the high-quality development market.
// Some Thoughts on Innovative Development of Integration of Geology, Geotechnical and Structure
With the accelerating pace of urban modernization, the engineering conditions are complex and changeable, and the engineering difficulty is increasing day by day. All links of the project are coordinated and all parts are coordinated. Green construction and high-quality development have become the mainstream trend of the upgrading and development of the engineering industry. At this stage, engineering geology, geotechnical engineering and structural engineering are separated from each other in terms of professional practice. The technical connection and communication are not smooth enough, and a series of resource waste problems such as duplication of work, distortion of information transmission, and security of their own retention are prone to occur, even leading to engineering accidents 。 Geology, geotechnical engineering and structural engineering are mutually complementary and should be coordinated and unified Mutual combination, penetration, cohesion and interdependence Medium development.
// Some thoughts on technicians engaged in underground engineering
From my own experience, it is suggested that the technicians of geological, geotechnical, structural and other related underground works should extend more in relevant directions, Change the attitude of having boundaries and boundaries, seek opportunities to break boundaries and boundaries, actively integrate and integrate, and improve personal competitiveness and value 。
At present, the domestic survey and design model, especially the geology, geotechnical and structure related to underground engineering, is seriously fragmented, and the system is insufficient. In the underground engineering plate with the characteristics of concealment, regionalism and uncertainty, the integration and innovation development has the advantage of professional first mover and first mover.
Engineering construction is gradually entering the stock market from the incremental market. It is difficult to break through the bottleneck of the development of the traditional survey and design mode. The integration practice and R&D innovation of geological and geotechnical structures under the EPC mode are promising, especially for controlling the construction period and cost. Carry forward the spirit of craftsmanship and innovation, and continue to explore more advanced and reasonable scientific knowledge and engineering technology. Forerunners will first enjoy the dividends of innovative development of the industry value chain.
