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ISRM International Symposium on Rock Mechanics - SINOROCK 2009
Comprehensive Investigation On Roadway Intersection Stability of Coal Mines In China
Lu, T.K. (School of Energy Science and Engineering, Henan Polytechnic University) | Chen, X. (School of Energy Science and Engineering, Henan Polytechnic University) | Guo, B.H. (School of Energy Science and Engineering, Henan Polytechnic University) | Mao, J.S. (School of Civil Engineering, Xian University of Science and Technology)
ABSTRACT There are large numbers of roadway intersections constructed annually in Chinese coal mines with various geometries, such as, three-way intersection, four-way intersection, two dimensional roadway intersection and three dimensional roadway intersection, etc. With continually increasing the depth of cover, the stability of roadway intersection is susceptible to ground control problems due to inherently wide roof spans and complicated intersection geometry used. The paper presents the comprehensive results obtained from the field monitoring and numerical modeling related to the stability of the roadway intersection in coal mine. Firstly, the basic geomechanical behavior of roadway intersection has been determined by using underground monitoring in great depth of cover, and then the numerical modeling is conducted to determine the stability behavior of intersection associated with the different geometrical shapes, the depth of cover, and construction sequence and direction on the stability of intersection. The results clearly indicated that large span of the opening and great depth of cover are major factors, which may influence the stability of the roadway intersections. Comparing different geometrical shapes of the two-dimensional intersections, the most unstable one is the cross-intersection, and results indicated that the construction sequence and direction are also sensitive factors for the stability of roadway intersection. 1 INTRODUCTION From the statistical data, it is noted that the roof failure mainly occurred around the large span of underground opening, and the situation is getting worth, when the complex geometrical structures and deep mining conditions are encountered. This paper is describes the stability and failure characteristics of intersection on the basis of literature review and study of the stability and failure behaviour of different geometrical structure of intersection, which commonly used in underground of coal mine in China, associated with various depths of cover using numerical simulation. It is noted that the geometrical shapes used in China coal mining industry is much complex, comparing with major coal mining countries in overseas, such as Australia and USA. With increasing the depth of cover, it is susceptible to ground control problems due to the complex geometries of underground structure. 2 PREVIOUS INVESTIGATION ON UNDERGROUND INTERSECTION IN COAL MINES Stability of underground intersection had been paid attention previously, even in the shallow condition. The investigations had been conducted to study the structural characteristics, stability and failure bahaviour in the shallow condition by former US Bureau of Mine (Hanna, 1991). In 1976, Balachandra studied the stability of intersection using underground monitoring and computer simulation. The department of mining engineering from West Virginia University studied the stability of three-way intersection with different geometrical parameters, and it found that the tensile stress is the main reason to cause the failure of the intersection. Comparatively, the threeway intersection is more likely having shear failure than the cross intersection. It is concluded that the tensile and shear failure on the roof strata increased with the reducing of angle between two roadways (Peng, 1978). The department of mining engineering from University of Wollongong also studied the stability of the T-intersection (Singh, 2001).
- Asia > China (1.00)
- North America > United States > Virginia (0.24)
- North America > United States > West Virginia (0.24)
- Transportation > Ground > Road (1.00)
- Materials > Metals & Mining > Coal (1.00)
ABSTRACT A Regulation 33 Geotechnical Assessmnet was carried out for Castle Cement Limited, in accordance with the Quarries Regulations 1999, approved Code of Practice (ACoP), at their Grange Top Quarry near Ketton, Rutland, UK in 2008. The assessment identified a total of 10 tips within the quarry for which the operator faced various constraints and could not undertake operations practically and in accordance with a completely โlow riskโ methodology. In order to reduce the impact of the constraints a methodology was formulated which entailed increasing stockpile height some by 100%, increasing face angles and utilizing rock fill for features such as noise bunds. The proposed methodology was categorized as a medium risk. Once the methodology had been formulated it was proven by a range of numerical models including limit state and finite element and probabilistic analysis relating to material parameters, slope angles, groundwater, precipitation and also impact on third parties. Finally, upon commencing works, a monitoring regime was put in place to ensure that the proven methodology could be observed and any divergences could be highlighted and input back into the probablistic analysis in order to devise a new way forward for that particular constraint. 1 INTRODUCTION This paper documents the approach undertaken for Castle Cement Limited in order to identify the factors affecting the safety and stability of stockpiles within their Grange Top quarry facility in the context of a Regulation 33 โGeotechnical Assessmentโ and formulation of โExcavation and Tip Rulesโ. Both were undertaken in accordance with the UK Quarries Regulations 1999, Approved Code of Practice (ACoP). Particular emphasis is placed on how the identified hazards were assessed and how a pragmatic and economic solution to the ongoing requirements of complying with the Quarries Regulations 1999 was arrived at. 1.1 Base Geology Data An initial Regulation 33 Assessment appraisal in 2001 summarised the engineering characteristics of the strata within the Quarry. This is presented in Table 1 (below). (Table in full paper) The report did not identify the stockpiles within the quarry to be significant hazards in accordance with the Approved Code of Practice (ASoP) and were described as generally small in volume. It was proposed that stockpiles within the quarry area be limited to less than 7.5m in height and graded in all cases to inherently safe angles of less than 22. 2 GEOTECHNICAL ASSESSMENTS 2008 2.1 Methodology The 2008 Geotechnical Assessment comprised of field reconnaissance, measurements and observations of rock and soil formations, faces, slopes, tips, stockpiles, ramps and lagoons recorded at key areas around and topographical survey. These built upon and developed information from the previous assessment which also included intrusive ground investigations and laboratory testing. The assessment comprised inspection and evaluation as follows:Qualitative assessment of the stockpiles and slopes were undertaken, providing a stability risk (potential for failure) and safety risk (consequences of failure) associated with the geotechnical characteristics at each location; The hazard associated with each feature was evaluated and classified as significant.
ABSTRACT Chatree Gold Mine is the largest open pit mine in Central Thailand which produced 74,137 ounces of gold in July 2007 โ June 2008. The Chatree deposits consist of complex andesitic centers adjacent to the rhyolitic centers. Structural geological of interested area (CH pit) can be divided in to 3 main structures: sheared zone, andesite dykes and faults. The point discussed in this paper is general production blasting practice and controlled in 6 meters bench using three main blast patterns with powder factor between 0.35 and 0.80 correlated to rock type. Trim blasting and pre-split blasting have been proposed, trialed are also include. The present practices are mentioned. 1 INTRODUCTION 1.1 Background The Chatree Gold Mine is located 300km north of Bangkok in Thailand. The Chatree deposit was discovered in 1995 in an area not previously recognized as having potential for significant gold mineralization. Mining leases were applied for and granted in 2000 and Chatree North Project mining leases were granted in 2008. The Chatree Gold Mine commenced production in November 2001 after a 12 month construction period. Load and haul is done using a fleet comprising of O&K RH40E excavators, Cat 773 and 740 trucks, Cat 14M Grader and Cat D8 and D9 Dozers. Mining and haulage are done by local Thai contractor, Lotus Hall Mining. This contract was updated in 2007 to allow for a new and expanded mining fleet, supported by Caterpillar, for increased production at Chatree for the year ended 30 June 2008 was 74,137 ounces of gold and 232,039 ounces of silver. The mine is conventional open pit operation consisting of three currently operating mine areas (A,K east and C cutback) and six closed pits (p, CH,H west, H south, D and S). the mine area spans approximately 7.5 km by 205 km and the deepest pit wall is 153 meters from surface (Plate 1). (Plate in full paper) The slope angle is designed correlated to rock types, which are 35The slope angle is designed correlated to rock types, which are 35 in laterite layers, 45 โ 50 in transitional rock and sheared rock, and 60- 65 in fresh rock. Catch benches of 5โ6 meters are introduced every 18 meters bench height. Blasting is done every 6 meters for two excavation flitches of 3 meters. This paper detailed the procedures and practices that have been developed for a production blasting and anear-wall blasting in Chatree Gold Mine closed and currently operating pits. 1.2 Geology The Chatree deposits are located in the Western-Edge Khorat Plateau Gold Belt at the boundary of Phichit and Phetchabun Provinces, central Thailand. The deposits consist of complex andesitic centers interdigitate and are overlain by fine-grained volcaniclastics and epiclastic siltstones, mudstones and fossiliferous limestones. Instructions of diorite to dolerite occur in the region. There are also stocks and swarms of ddykes and faults in the area and granitic intrusions are associated with regional structural trends. While CH pit is dominantly composed of lithic rich fiamme breccias, polymitic and andesite to andesite porphyry.
- Asia > Thailand > PheTchabun > Phetchabun (0.24)
- Asia > Thailand > Bangkok > Bangkok (0.24)
- Geology > Mineral > Native Element Mineral > Gold (1.00)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock (0.53)
ABSTRACT The Deep Underground Science and Engineering Laboratory (DUSEL) is being constructed within the footprint of the defunct Homestake Gold Mine, located near Rapid City, in South Dakota, United States of America. The DUSEL will provide scientists and engineers with a dedicated facility capable of supporting a broad spectrum of fundamental and applied research within the Earth's crust to depths in excess of two kilometers. Major research partners of this multi-disciplinary facility are physicists, biologists, geochemists and rock engineers. The potential range of experiments is bored and as plan are developed it is expected that opportunities for cross-cutting, synergistic research will emerge. Physics proposals call for the construction of rock caverns with excavated volumes in excess of half a million cubic metres, spans of over 50 metres, sited at depths of up to 1.5 km. the paper will outline the range of rock mass conditions anticipated at the site and discuss key end-user requirements and design criteria that are likely to play determinant roles in the selection of preferred sites and experimental options. The paper will underline the need for upfront investigation of candidate sites and the potential benefits of incorporating engineering research into the design and construction programme. 1 INTRODUCTION The Deep Underground Science and Engineering Laboratory (DUSEL) will be a new facility dedicated to underground research. DUSEL will bring together a diverse group of science and engineering partners interested in conducting a new generation of experiments deep within the Earth's crust. To accomplish its goals, DUSEL is being planned as a multi-level underground facility with laboratory campuses sires from near surface to over two kilometres in depth. The main campus facilities will include dedicated space for laboratories, workshops and offices, all connecting to a site-wide infrastructure network. "Outpost facilities" are also planned to provide for drilling and sampling in zones of geologic and biologic interest. Additionally, rock mass volumes may be isolated under user-controlled conditions to study key topics in rock mechanics and the earth sciences, such as rock mass behaviour under stress and water flow in fractured aquifers. DUSEL will offer rock engineers opportunities to test new techniques, equipment and materials, both as an integral part of the DUSEL design and construction process, and as independent engineering research tasks, undertaken at dedicated experimental sites. Existing underground physic laboratories have more typically been built within mine footprints or adjacent to road tunnels. These laboratories benefit from access to underground expertise and cost defrayment for construction, access, infrastructure and operation, but suffer the constraints that a junior partnership necessarily entails. Unlike such "parasite sites", the DUSEL facilities will be purpose- built and operated for research alone. According to Kotcher (2008) half a billion dollars have been indentified to finance the construction and operation of the DUSEL facility. This budget is intended to support the reopening of the Homestake mine to its full depth and fund frontier research in a broad range of disciplines.
- Geology > Geological Subdiscipline (1.00)
- Geology > Structural Geology > Tectonics > Plate Tectonics (0.44)
Development of the 3D Underground Space Information Management System (USIMS) For the Maintenance And Health Assessment of Tunnels
Nakai, T. (Earthtech Toyo Co. Ltd) | Ryu, M. (Earthtech Toyo Co. Ltd) | Koyama, T. (Kyoto University) | Nishiyama, S. (Kyoto University) | Ohnishi, Y. (Kyoto University)
ABSTRACT For the construction, maintenance and reinforcement of the tunnels, the new concept called asset management has been introduced and paid attention recently. For the asset management, the key issue is how to define, monitor and assess the performance of the tunnels. The newly developed three-dimensional Underground Space Information Management System (USIMS) enables to store and integrate all types of information related to the construction, inspection, maintenance and reinforcement systematically with a 3-D virtual world. In this study, for the purpose of the tunnel maintenance and health assessment of thetunnels, the comprehensive tunnel database was constructed using USIMS based on the geological data at the tunnel site, construction data, regular inspection records and photo, and etc., which were stored as a hard copy and/or digital format. By updating this tunnel database, time evolution of the tunnel status such as deformation etc. can be presented with clear 3D vision. 1 INTRODUCTION Due to the economical, political and social changes in Japan, the construction industry has to shift the focus from building new infrastructures to maintaining existing infrastructures. The life of the infrastructures will be extended by regular maintenance considerably and this is especially true for tunnels, the new concept called asset management has been also introduced and paid attention. One of the key issues for asset management for tunnel is how to define, monitor and assess the performance of the tunnels. It is also important to register geological and construction related data and store them for the future use such as the maintenance and repair/ reinforcement of the tunnels. At each stage (construction, maintenance and repair/reinforcement), large amount of data are gathered that should be stored and retrieved for the later stage. The newly developed three-dimensional Underground Space Information Management System (USIMS) as presented in Ohnishi et al. (2005) enables to stores and integrate all types of information related to the construction, inspection, maintenance and reinforcement systematically with a 3-D virtual world. In this study, for the purpose ofthe tunnel maintenance and health assessment of the tunnels, the comprehensive tunnel database was constructed using USIMS based on the geological data at the tunnel site, construction data, regular inspection records and photos, and etc., which were stored as a hard copy and/or digital format. By updating this tunnel status such as deformation, cracks etc. can be presented with clear 3D vision. 2 The USIMS: outline The USIMS was developed and extended to construct comprehensive tunnel database and used for the regular inspection work of tunnel without any difficulties and time consuming works for tunnel engineers and managers. The basic tunnel database mainly consists of the geological data at the tunnel site (rock type, fractures, etc), tunnel profiles (length, cross, section, etc.), tunnel construction data (excavation method, tunnel support patterns, concrete lining, excavation face, etc). The main features of USIMS are as follows;pre-existing documents (hard copies) such as old construction data, inspection results, etc can be transcribed and treated together with current CAD based data,
ABSTRACT Sub- level open stoping method was implemented on an experimental basis in an underground manganese mine situated in central India. The objective was to evaluate its feasibility as a routine method of mining over the conventional cut and fill stoping method. This paper presents the investigations conducted for stability assessment ofthe hang wall and the crown pillar during excavation from this experimental stope vof 22.5 m length and 33.3 m height. The manganese ore body at this mine was 13 to 20 m thick with a dip of around 75โ80ยฐ. The hang wall consisted of week decomposed quartz free schist whereas the foot wall consisted of a strong quartz muscovite schist and quartzite. Multipoint Borehole Extensometers were installed to monitor the hang wall deformation during the excavation from this stope. The crown pillar stability was monitored through acoustic emission sensors. The monitoring results revealed no significant movement of hang wall rock and crown pillar. The stope was successfully excavated in around thirteen months period and remained fairly stable without any backfilling. This study had critically helped the mine management to evaluate the feasibility of sub level open stoping method in the given geo-mining conditions of this mine. 1.0 INTRODUCTION The Indian Manganese deposits are normally found as bedded sedimentary deposits associated with Gondite series. The manganese mining in India is principally done by Manganese Ore India Limited, a Government of India undertaking company. It has eight underground manganese mines all of which are situated in the central region of India. The geological formation of manganese deposits in all the mines are found to be of same age and hosted by similar rocks. The common mineral contents are pyrolusite, psilomelane, braunite, bixbyite and mangnite. They are normally fine grained which renders the ore body weaker. The host rocks which are quartz, muscovite schist and quartzite are also not strong at all places. The ore body is steeply dipping and as such, the underground mining is not only difficult but unproductive also due to limited mechanized operations. The conditions are expected to be more severe in the coming years with gradual increase in the depth of workings. The sub level stoping is a proven method of mining in strong rock condition where the ore body and both hanging wall and foot wall are strong enough to withstand the heavier mining practices. This method is considerably productive, safe and economical. The cut and fill method of stoping was typically characterized with low productivity and limited mechanization at almost all underground manganese mines in India. This led to the proposal for evaluating the techno economic feasibility of sub level open stoping method on an experimental basis. The Chikla Mine, which was situated in the central region of India was selected for this experiment for its suitable rock conditions. The cut and fill stoping method was otherwise routinely used at this
- Geology > Mineral > Silicate > Tectosilicate > Quartz (0.64)
- Geology > Rock Type > Metamorphic Rock > Quartzite (0.44)
- Geology > Rock Type > Sedimentary Rock > Organic-Rich Rock > Coal (0.40)
Stability Monitoring of a Sub-Level Open Stope Through Rock Mechanics Instrumentation And Acoustic Emission Measurements In a Manganese Mine In India
Jhanwar, J.C. (Central Institute Of Mining And Fuel Research Regional Centre) | Chakeaborty, A.K. (Central Institute Of Mining And Fuel Research Regional Centre)
ABSTRACT Sub- level open stoping method was implemented on an experimental basis in an underground manganese mine situated in central India. The objective was to evaluate its feasibility as a routine method of mining over the conventional cut and fill stoping method. This paper presents the investigations conducted for stability assessment ofthe hang wall and the crown pillar during excavation from this experimental stope vof 22.5 m length and 33.3 m height. The manganese ore body at this mine was 13 to 20 m thick with a dip of around 75โ80ยฐ. The hang wall consisted of week decomposed quartz free schist whereas the foot wall consisted of a strong quartz muscovite schist and quartzite. Multipoint Borehole Extensometers were installed to monitor the hang wall deformation during the excavation from this stope. The crown pillar stability was monitored through acoustic emission sensors. The monitoring results revealed no significant movement of hang wall rock and crown pillar. The stope was successfully excavated in around thirteen months period and remained fairly stable without any backfilling. This study had critically helped the mine management to evaluate the feasibility of sub level open stoping method in the given geo-mining conditions of this mine. 1.0 INTRODUCTION The Indian Manganese deposits are normally found as bedded sedimentary deposits associated with Gondite series. The manganese mining in India is principally done by Manganese Ore India Limited, a Government of India undertaking company. It has eight underground manganese mines all of which are situated in the central region of India. The geological formation of manganese deposits in all the mines are found to be of same age and hosted by similar rocks. The common mineral contents are pyrolusite, psilomelane, braunite, bixbyite and mangnite. They are normally fine grained which renders the ore body weaker. The host rocks which are quartz, muscovite schist and quartzite are also not strong at all places. The ore body is steeply dipping and as such, the underground mining is not only difficult but unproductive also due to limited mechanized operations. The conditions are expected to be more severe in the coming years with gradual increase in the depth of workings. The sub level stoping is a proven method of mining in strong rock condition where the ore body and both hanging wall and foot wall are strong enough to withstand the heavier mining practices. This method is considerably productive, safe and economical. The cut and fill method of stoping was typically characterized with low productivity and limited mechanization at almost all underground manganese mines in India. This led to the proposal for evaluating the techno economic feasibility of sub level open stoping method on an experimental basis. The Chikla Mine, which was situated in the central region of India was selected for this experiment for its suitable rock conditions. The cut and fill stoping method was otherwise routinely used at this mine. The stability of hangwall(H/W)and crown pillar were considered as key to the successful implementation of sub level stoping method at this mine.
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Mineral > Silicate > Tectosilicate > Quartz (0.64)
- Geology > Rock Type > Metamorphic Rock > Quartzite (0.44)
ABSTRACT A new commuter train tunnel under Stockholm City is currently being designed. The main portion of the tunnel is to be constructed in crystalline bedrock using drill and blast methods together with conventional support elements in the form of shotcrete and rock bolts. Standard rock reinforcement classes, which are dependent on excavation span and rock mass quality, will be used to determine the required reinforcement for the majority of the tunnel system. The rock mass was divided into four rock classes (A-D) and the tunnel into four categories for excavation span. Potential failure mechanisms were identified for the different combinations of rock mass quality and excavation span and appropriate analysis methods were selected for the various combinations. For all analyses, a range of material properties and initial stress conditions were used to account for natural variation in the input data. Preliminary standard reinforcement classes were determined by evaluating the results from all analyses and using the application of engineering judgment. Numerical analyses, including the preliminary reinforcement were then carried out for chosen combinations of rock types and tunnel sizes. 1 INTRODUCTION A new commuter train tunnel under Stockholm City, denoted the City Line, is currently being designed. The tunnel comprises a 6 km long double-track tunnel with two underground stations (Odenplan and City), service tunnel and exits to ground surface and existing subway tunnels. The main portion of the tunnel is planned to be constructed in crystalline bedrock using drill and blast methods, with conventional support elements in the form of shotcrete and rock bolts. The City Line connects to the existing rail network at Tomteboda in the north and to the existing station Stockholms Sรถdra in the south, see Figure 1. This paper presents the methodology used to design the standard rock reinforcement classes for the City Line. The standard reinforcement classes are to be used for the majority of the planned tunnel system. Standard reinforcement classes will not be used in areas with low rock cover (less than half of the tunnel width), crossing points with existing tunnels, tunnels with a span greater than 20 m, and poor rock quality. The City Line is, with respect to civil works, divided into 5 different contracts: a) Odenplan/Vasa, including single- and double-track train tunnels, service tunnels and an underground station, b) Norrmalm, including single- and double-track train tunnels and service tunnel, c) Norrstrรถm, including single- and double-track train tunnels, service tunnels and an underground station d) Sรถderstrรถm, including a submerged concrete tunnel (not included in these analyses), and finally e) Sรถdermalm, including single- and double-track train tunnels and service tunnels. The same design methodology was used for all contracts. (Figure in full paper) 2 INPUT DATA FOR ANALYSES A comprehensive geotechnical site investigation was conductedtocharacterizethegeologyalongthe plannedtunnelalignmentforeachcontract. Project guidelinesformappingandcoreloggingwere establishedearlyinthedesignphasetoensure consistencyinthedescriptionandcharacterizationof therockmass.
- Transportation > Ground > Rail (1.00)
- Transportation > Passenger (0.81)
ABSTRACT Drilling and blasting is an old and known method of excavation, both for underground and surface applications. Over the years, many researchers have investigated on different aspects of this method while determination of specific charge has been one of the most challenging topic. Many specifications of rock and explosive material are influencing the amount of required charge for each application and the conventional methods can not easily incorporate all of them. This research focuses on using "artificial neural networks" for prediction of specific charge based on certain input parameters. Results show that the method is very powerful to do so with high accuracy. However, increase of number of data can significantly improve the performance of the model. 1 INTRODUCTION Drilling and blasting (DAB) is one of oldest methods for rock excavation in underground and surface structure. This method is vastly used in Iran for mining as well as many civil engineering tunnels e.g. road tunnels, water tunnels, underground power planets, etc. Existence of large mountain chain in Iran necessitates a lot of tunnels, in different shape and size, for various applications. DAB method is more suitable for most cases, comparing to mechanized excavation, due to its significant flexibility, low investment cost and not requiring high technology. Results of any blasting operation are affected by interaction between explosive materials and rock mass. Thus, knowledge of rock parameters can lead to optimization of blast results and powder factor. Parameters affecting blast results may be categorized as followings [1]:Explosive specifications Rock mass specifications Tunnel and blast hole geometry Many models have been proposed for prediction of specific charge; most of which are mainly developed using a technique for regression analysis. A few decades ago the idea of artificial intelligence system was presented. Since then, the system was employed to solve many problems and could even serve to daily industrial problems. Artificial neural networks (ANNs), as one of the powerful tools in this system, have been able to bring advantages for solving engineering problems. Application of ANNs, as a pattern recognizer for nonlinear behavior prediction of specific charge in underground excavations, forms the core of this research. Using suitable input parameters, could lead to a reliable ANNs models for accurate prediction of specific charge in tunneling. 2 DATA USED TO DEVELOP THE MODEL The data used in this research was measured in filed by Chakraborty et.al in India [2]. As seen in Table 1 these data are from four cases, field investigations were conducted by Chakraborty in inclined drifts of a coal mine, development galleries of two metal mines and a tunnel of a hydro-electric project. The sites are listed in Table 1. Certain methodologies were adopted for obtaining data; reader is referred to Chakraborty et.al [2] for more information. (Table in full paper) 3 INFLUENCING PARAMETERS 3.1 Relevant parameters Using a specific type of explosive, rock mass characteristics and geometry of tunnel and blast holes are the main parameters, which affect the specific charge.
- Research Report > Experimental Study (0.69)
- Research Report > New Finding (0.54)
ABSTRACT Wuncunshan tunnel on JC3 bid section of airport Highway in Xiamen, which locates in busy downtown area and goes underneath 67 buildings with shallow foundation, is expected to control the surface settlement caused by tunnel excavation. Multi-arch tunnel method and neighborhood tunnel method were both tested by design and excavation unit in order to understand which is more effective to control the surface settlement. Based on in-situ measurement and numerical simulation, this paper contrasts and analyzes measurement data and numerical results of the two excavation methods including transverse and longitudinal surface settlement and individual effect of sub-hole excavating and dismantlement supports. Some conclusions are obtained, which provide good reference for design and excavation of similar tunnels. 1 INTRODUCTION With the development of high-grade highway construction, space between left and right of twin-tunnel can't satisfy the request of permitted limits, owing to the especial geology, landform condition, join means, collectivity line type and engineering cost. Considering of techno-economy and environment benefit, multi-arch tunnel and neighborhood tunnel become important choice schemes, especially in short or medium length tunnel and the adit of long length tunnel. Multi-arch tunnels are wide application to the special sections of the high-grade highway, since the Baiyushan tunnel in Guangzhou, which is the first multi-arch tunnel in china completed in 1993. Compare to general twin-hole tunnel, multi-arch tunnel requires little of connection landform, and links conveniently and smoothly to outer line. However, there are still some problems including much procedure, frequent transformation of structure force, high construction difficulty and high engineering cost and water leakage of the middle wall. Neighborhood tunnel is one kind of structural style between the ordinary separate tunnel and multi-arch tunnel, which can reduce construction procedure and lower engineering financing, especially solve the problem of waterproof and drainage completely. However, as neighborhood tunnel has been less built in China, some key construction technologies need further study. The main problem for neighborhood tunnel is that, according to different surroundings, how much space and which necessary measures can meet engineering requirements and guarantee its security. Wuncunshan tunnel on JC3 bid section of airport Highway in Xiamen, locating in busy downtown area and going underneath 67 buildings with shallow foundation, is required to strictly control the surface settlement caused by tunnel excavation. Multi-arch tunnel method and neighborhood tunnel method were both tested by design and construction unit in order to understand which is more effective to control the surface settlement. This paper contrasts and analyzes monitoring data and numerical result of the two tunnel methods based on in-situ monitoring and numerical simulation, and some useful conclusions for design and construction of similar tunnels are obtained. 2 PROJECT PRENSENTATION 2.1 Project background Wuncunshan tunnel on JC3 bid section of airport Highway in Xiamen, locating in busy downtown area, is a highway tunnel consisting of 3 lanes in each direction. As the tunnel goes underneath 67 buildings with shallow foundation, the surface settlement caused by tunnel excavation need to be controlled strictly.