Research conclusions:Through researching, it isunderstood thatGypsum karstbreccia has specific horizon, locating at the first segment in each formation of the medium series ofOrdovician System. Mostof it is special flexible rock with greatdifferences in strength. According to the difference of cementation, gypsum karst breccia is classified as slight cementation, weak cementation, moderate cementation, strong cementation. According to the grain composition, the material componen,t its forming environmentand the cemented degree, the gypsum karstbreccia can be divided of four kinds: the boulder shape, stone coated bymud shape, shapewith the gravel and the hard soil shape. The engineering geological survey should be strengthened forFengfeng Fm ofOrdovician system.

Research conclusions:Through the analyses of the reasons for formation of the slope deformable body and the characteristics ofslope deformable body in the creep deformation stage, the proposalwasmade the integral treatment had to be conducted. Namely, the slide -resistantpile was adopted for reinforcing the down part of the slope deformable body, the anchor-framed framework was adopted for reinforcing the steep surface and the deep foundation slide –resistant key was adopted for reinforcing the middle partof slope deformable body. After conducting these treatments,the slope deformable bodywas stable entirely andwell stood theWenchuan Earthquake and heavy rain.

Research conclusions:Zhanlongya landslide belongs to extremely big landslide with sliding volume about118x104m3 due to the effectof"5?12" Earthquake in Wenchuan. There are lots ofenvironmental conditions to form landslide and external sectors to aggrave the landslide developmen.t These conditions and sectors are still changing now to threaten the traffic safety ofPingshui Highway and safety of the house and farming fields. Once barrier lake forms, itwillproduce the serious losses ofupper and down streams. Based on the formation reasons, formation conditions and loss of landslide,the evaluation of the effectof treating landslide is made. If the landslide can be treated in time, the life environmentcan be improved much.

Research conclusions:There are Semi -fixed dune and active dune along Qinghai –Tibet Railway. The sand flow is developmentand river area is also the place where the sand storm happens frequently with complicated and violent movemen.t The control of the sand storm in this area is long-term process. The principle of" PuttingPrevention First and Combining Prevention with Control" should be followed by adopting the method ofputting the project prevention of sand storm first and adjusting measures to local conditions to conduct comprehensive contro.l During the operation of Qinghai-Tibet Railway, it isnecessary to do the studies on the technologies forcontrolling the sand storm and ensuring the safety of the railway in sand storm area and river area. The accumulated sand should be cleaned up in time and environmentprotection should be strengthened.

Research conclusions:From the analysis of the deficiency in the previous design, it is pointed out that the length of anchors(or cable -anchors) mustbe selected reasonably according to the slope -ratio and the bed parameters, and the potential sliding-surface of a slope would be determined on the base of the stability analysis at first for ensuring the anchors(cable -anchors) fixed in the stable bed. The anchors(or cable -anchors) would be painted with epoxy,chlorosulfonated polyethylene coatings, or insulated by a iron wire -netdirectly, or the integrated antisepic measures would be taken for the anchors. Adopting these measures could insulate the touch of eroding matter with the reinforcements(cables). Especially the physical insulation could cutoff the continuity of the cracks caused by the tensile force, obtaining a very good protection effectand ensuring their service life availably.

Research conclusions:From the comparison and analysis of the bench protection slope and the anchors (or cable -anchors) frame plus the vegetation concrete afforestation protection slope used for the high side slope in previous construction, it is known these two methods have deficiencies and can notmeet the stability requirement of the side slope. Through research, a new ecology protection structure is offered for crag rock -natured high side slope. This structure can combine the perfectreinforcementeffectofanchorson the shallow unstable bodywith the good effect of the vegetation concrete affore station protection slope to achieve the goals of protecting the side slope and improve the construction environmen.t This structure has been applied in protecting the high side slope of new Lijiang Railway Station, obtaining the good results.

Research conclusions:The Cambridge model belongs to the isotropic hardened elastic mode,l which is adaptive to the soft soil in the subgrade experiment section ofBeijing-Tianjin Intercity Railway with consideration of the water-press yield characteristics, the press rigidity, the shearing shrinage and the effects of load and download. The determination method for the test parameters of the model is simple for easy usage. Using the modified Cambridge model as the constitutivemodel is scientific and resonable. The testcurve is obtained from the ordianary triaxial compression test for providing the necessary parameters to the Cambridgemodel and providing the basis to numerical simulation calculation. The accuracy ofK0consolidatin test is improved and the model parameters are optimized through upgrading the triaxial device. These parameters can be as the reliable parameters to calculation of post -construction subsidence of the subgrade ofhigh -speed railwaywith Cambridgemodel.

Research conclusions:Using dry jetmixing pile to reinforce the soft soil foundation ofhigh -speed railway is feasible.There is a little difference in piling strength by using the differentmachinemodelsofdry jetmixing pile, but there isbig difference in piling strength by using differentmachine unitof the samemode.l The unconfined compression strength of dry jetmixing pile ishardly influenced by the cyclicmixing of10m pile and allpile, adding the cyclic number of mixing and the different stratum. Selection of construction ismore important than selection of constructionmachine for the dry jetmixing pile construction. When the pile length iswithin 10m, the unconfined compression strength ofdry jet mixing pile is even, achieving perfect construction quality. For ensuring the construction quality, the dry jetmixing pile construction demands strict management.

Research conclusions:The the static and dynamic analysesof the supermajoroverpasson the 3rd ring road in Chengdu show that all indexes of the bridge meet the code requirements. As the bearing force at joint point of arch beam is complicated, the three -dimensional prestressed structure should be designed, the beam end ofmain beam should be widened and heightened, andwebs should be thickened. The stress concentration happens in some partsbecause of the complicated structure. Based the research and calculation, the applicable range of tied arch structure in construction of railway bridge iswidened by adopting new scientific research achievements and theories athome and abroad and it can provide the reference to the similar works.

Research conclusions:Through establishing the dynamic analysis mechanic model for twin towers single cable –stayed bridge, the dynamic characteristics and temporal process of earthquake are analyzed for twin towers single cable –stayed bridge with finite element method. The modal analysis shows the first modal of twin towers single cable -stayed bridge is the vertical symmetrical bend ofmain beam, with bigger self -vibration frequency than the floating cable –stayed bridge, so the twin towers single cable -stayed bridge ismuch influenced by vertical earthquake, wind and vehicle vibration. The internal force and deformation law of the structure of the bridges encountered many earthquakes are studied, and the seismic performance of the cable -stayed bridge is analyzed. The study shows some cable –stayed bridge canmeet the seismic requirement stipulated in the design code under effect of encount eringmany earthquakes with the transcendental possibility of 10% in 50 years.

Research conclusions:(1) At the place of the same elevation with the box culvert axis, the soils in front of working face generate the biggest horizontal movements. (2) By monitoring the contact stresses between soil and the culvert wal,l the effort of grouting and the total jacking forces can be obtained. (3) The box culvertcan be jacked in along the design path by adjusting jacking forces. (4) The pore pressure is a sensitive and exactindex for monitoring the vibration of soil in the process of box culvert jacking.

Research conclusions:Only distortion and stressofbridge is controlled in construction and themoulding board elevation is ensured, the bridge type of line and stressdistribution can satisfy the design requirement. The distortion measurement should be conducted before sunrise to eliminate effect of temperature difference. The real field measured values of the concrete elasticmodulusmustbe adopted in computation. In construction control of this bridge, the errors happened in construction is modified by adopting parameter identification method, obtaining a good resul.t As the effect sofshrinkage and creepage are evident in stress testing, the effect should be calculated to each construction phase for the clear and easy usage.

Research conclusions:In typical geological survey for the tunnel in complicated metamorphic rock tunnel project geology, the technology with rapid and money-saving characteristics for comprehensive physical exploration was used,and with it the unfavorable geological body in deep underground was clearly revealed, the precision ofgeological survey was improved much and the accident hidden peril was lowered hugely. This can be as the reference to the similar works.

Research conclusions:Under this geological condition and specially pushing force of shield, the maximum of the ground subsidence is12. 9 mm, and the maximum rise value of ground is0. 7 mm.They satisfy the design requirements. After the completion of the existing tunnel and taking some measures, the corresponding consolidated subsidence value is 1. 8 mm. Thewidth of subsidence slotunder the tunnel floor is 60 m. The subsidence curve is relatively fla,t which satisfies the lateral differential subsidence demand of the existing tunnel.

Research conclusions:The on site monitoring resultof the settlement is greater than the calculation resul,t butitdoesnot affect the traffic safety of the railway. Due to the impact of train operation, the trough width and depth of surface settlementcaused by the under-passing railway are both greater than those of the adjacentPeace Road.

Research conclusions:As there is no uniform standard for selection of the float-resistant water level and the current theory aboutcalculating buoyant force doesnot regard the penetration of the soil layerswhere the tunnel structure is on,the design result of float-resistance deviates from the real situation. From the analysis and calculation it is concludedwhen the pile length ofupliftpile is longer than 10m, the sectional reinforcementshould be conducted to save the cost. The possibility of taking uplift pile as load bearing pile should be considered in design of the uplift pile, and the influence of installation ofupliftpile on the internal force of the tunnel structure should be calculated.

Research conclusions:The calculation method for vertical earth pressure stipulated in the current code for design of tunnel is inapplicable for the shield tunnel in soil layer. Forsoftclay stratum, the load model of allearth -pillars can be used to calculate the verticalearth pressure fordesign. Forotherstratums, no matter what the soil depth is, the Terzaghi Arch Theory can be used to calculate the verticalearth pressure, but for sand stratum, the groundwaterpressure and soil pressure should be calculated separately.

Research conclusions:(1) The scheme for treatment of inrush mud and collapse is reasonable. (2) The support in advance along with grouting reinforcement of the inrushmud and collapse areaGangcheng Tunnel is an effective way to treat collapse and inrush mud. (3) The treatment of the collapse and inrush mud of Gangcheng Tunnel shows the geological forecast in advance is essential to the safe construction of tunnel.

Research conclusions:For disaste rprevention and relief in tunnel, the principle of"putting prevention first, combining prevention with elimination, making self -relief easy and safe evacuation" should be followed. Train should be prevented to enter into the fire tunnel. The train should notstop in tunnelwhen itfires, and if the train has to enter into tunne,l itmust stop at the "emergency relief station" in the tunnel for evacuating people. When a train fires in tunnel and if it is cable tomove continuously, the basic principle of"first drawing the train outof the tunne,l then breaking up the train and treating the fire disaster" should be followed. Installation of the operational ventilation facilities should consider the requirements of the prevention and elimination of smoke and combine with the ventilation facilities for prevention ofdisaster. According to the principle of"simplicity, reliability andmoney-saving", the necessary devices for disasterprevention and relief should be installed in tunnel.

Research conclusions:The surrounding rocks of Caishenmiao Tunnel neither produces gas nor have the geological environment to storemuch gas. The gas in rock stratum comes from faraway and is of free state, so in genera,l the gas will not burst out suddently. The gas concentration will lower with the gas release through opens and ventilation.However, attention should be paid to the treatment measures and the danger of the gas and outcome caused by the gas should be known. The measres for gas prevention must be implemented one by one. The gas check and ventilation should be focused on to know the gas concentration in the tunne.l The holing must be conducted in advance while excavation ofworking face to control the gas concentration in the safe range. The gas block should be considered in tunnel strcture design to reduce gas escape asmuch as possible for ensuring the construction and service safety of the tunnel.

Research conclusions:Comparedwithwheel-rail train, the low /medium –speed Maglev train has better turning and climbing capacity and saves the engineeringworks and cos.t Compared with the urban rail transi,t the low /medium –speed Maglev train has the characteristic sofsafety, environmental protection, comfort, rapidity, low energy consumption and low cos,t and especially it is suitable for in urban mass transit.

Research conclusions:From the discussion on he overallgeological survey forMetro Line 2 inXia' n, it is concluded for the overall survey the key points and difficult points in the survey should be analyzed and judged, and the survey principle, the technical requirement and implement outline for the rock should be worked ou.t For ensuring reasonableness of the survey plan, the survey plan should be optimized, the factors and main links to influence the survey quality should be controlled, the operational procedure should be standardized, the survey report should be checked strictly, the correct geological information and the technical service should supply to the design and construction.

Research conclusions:The intercity railway is different than the other traffic modes and itmainly satisfies the travel demand of intercity passenger. There are lots of the influencing factors on intercity railway construction, mainly composes of internal factors and external factors. The internal factors include the traffic demand of intercity passenger,regional economic development leve,l urbanization process and development levelof the other traffic modes. The external factors include resource and environment benefits, passenger service quality, investment and financing modes and socially public welfare benefits. The intercity railway construction is a system aticalproject restrained bymany factors. So the comprehensive factors should be considered when making the decision to construct the intercity railway.

Research conclusions:The analyses of influencing factors on admission of intercity railway construction were made, including the traffic demand, traffic supply, construction fund, financing policy and measure and national guidance policy. The scientific sequential decision-making model was established and with it the analyses of sequential decision-making were made for four admissible railway systems. The results showed this model was scientific in method and feasible in operation, and application of this model could overcome the one -sideness of using single method and improve the believability of planning of intercity railway system.

Research conclusions:(1) For ensuring the safe construction of the entrance to the tunne,l it is necessary to take measures of reinforcing the bed ofentrance to the tunnel in advance and strengthening the primary support to the tunnel. (2) During the excavation of foundation pi,t some constructionworks for the entrance to themined tunnel can be done through reasonable construction organization fornotonly reducing the repeated works and speeding up the construction of the entrance to the tunne,l but also forensuring the stability ofopen cut foundation andmaking the tunnel safe entry.

Research conclusions:From the analyses, comparisons and field tests of several optional schemes, it is concluded the 3G system signals should be connected atend ofPOI. In the system ofcombiningmultiple networks into one network, in order to prevent the disturbances of signals each other, the insulation of the every network must be increased tomeeting the requirement. The 3G system can use the antenna subsystem of 2G system to reduce the construction cost and construction difficlty.