Research conclusions: For the last 30 years，the ground collapse of Guangzhou has been in the wave raising state with the obvious space － time distribution regulations． The human factor and heavy rain are main reasons for the ground collapse and they centrally happen in flood period from April to October． The karst collapses mainly happen in the hidden karst areas of the Huadu District，Baiyun District and Chonghua City within the Guanghua Basin． The ground collapse caused engineering mainly happens in the main city proper of Guangzhou． The underground excavation and pumping underground water can cause the ground collapses and they are proportional to the engineering volume and engineering strength． The plan as a whole，scientific site selection，adjusting structure and reasonable arrangement are the control countermeasures for the ground collapse．

Research conclusions: Based on the unsaturated silty clay and floury soil of Qingdao － Ji＇nan passenger special line，carried by the consolidation test and in － situ tests，the results show that the unsaturated silty clay and floury soil’s saturation is between 46% ～ 80% ，the compression modulus of which to calculate settlement can be comprehensively obtained through the consolidation test ，cone penetration test and standard penetration test; and the calculating settlement of which can be revised according to the empirical coefficient of the Code for design of building．

Research conclusions: The analysis allows to reach the following conclusions: ( 1) The unfaverable geological condition is mainly consisted of landslide and karst and the specific rock and soil is mainly formed by marlite and expansive soil． ( 2) The clauses stupulating no arrangement of reconnaissance point in the European Standards need to be neatly applied by engineers． ( 3) The lateral pressure test is irreplaceable for the structural design，the hole pressure test with water level gauge must be adopted in the drilling; and the deep displacement test can offer quantitive basis for the judgement of glide plane． ( 4) The readability of survey report and professional design that are combined in the filing facilitates design examination and constuction management．

Research conclusions: The results shows that the displacement － loading model provided in this paper can solve the ultimate bearing capacity of suction anchor accurately under combined vertical and horizontal loading． The ratio of horizontal and vertical loading and action point of loadings can influence the ultimate bearing capacity and the stability of the suction anchor． The contents of this research can give technical supports in engineering and theoretical direction to analysis．

Research conclusions: The maximum treatment depth of piles thrusted － expanded in column － hammer is 20 － 30 m． The result show that，dealed with 22 m piles thrusted － expanded in column － hammer，the roadbed rarely occures settment and the collapsibility of reinforced layer also eliminates． The roadbed don' t need to preload． Thus，piles thrusted － expanded in column － hammer can obtain the expected results in settlement controlling in large thickness collapsible loess site．

Research conclusions: For the great railways development，it is urgent to improve the small － sized track maintenance machinery in China． The hydraulic working principle of the rail straightener directly affects product performance，the structure design and the improvement have a direct impact on product availability and portability，the appearance design has a direct impact on product novelty，and the science of the performance test method directly affects the reliability of the product． The YZ － Q I － type rail straightener developed by reasonable design and structural improvement has the features of simple and compact structure，lightweight，safety，reliability，high speed，large load bearing capacity and convenient maintenance，and it is better than the similar products．

Research conclusions: From the research presented in this paper，it is known the right way to arrange prestressed tendons is the long tendons as the dominant role and the short tendons as the subsidiary role． The reasonable way to arrange prestressed tendons can effectively improve the structures ＇s load bearing condition，decrease the structure ＇s deformation，make the support reaction even between the internal curve and external curve，reduce the prestress loss and improve the structure＇s economical efficiency．

Research conclusions: The selection of the plan for erecting bridges is made． The working condition and the strength and current of the high voltage induction field under condition of 500 kV power line crossing in low altitude are calculated and analyzed on the base of the plan for erecting the bridge with bridge girder erection machine． The harm situation of the operational person and equipments is analyzed． The protective technical measures for ensuring the safety of the person，equipments and power facilities are offered．

Research conclusions: The comparison of the finite element calculation result with the actually measured result of the temperature field of the main cable of the bridge shows this calculation method is precise and reliable and it is available for calculating the temperature field of the main cable of the suspension bridge in the courses of design，construction and service．

Research conclusions: ( 1) The tunnel invert should be constructed to make the lining into closure condition as soon as possible during tunneling in the weak weathered granite rock section． ( 2) It is necessary for the CD method followed by invert excavation section and making the lining into a closure condition as early as possible． ( 3) Because of the possibility for the hydraulic connection between Wenxing tunnel and the reservoir，water samples should be collected in time to make a necessary chemistry and isotopic analysis to determine where the water seepage and gushing are from． ( 4) The secondary lining should be applied as soon as possible during tunneling in weak rock of the fracture zone． If necessary， a special anti water pressure composite lining design should be made． ( 5) Once the hydraulic connection between the tunnel and reservoir was confirmed and the deformation and mechanical condition of the tunnel in fault fracture zone waspoor． The cross － hole for vehicle should be kept away from the weak point，it is suitable to change forward or backward 10 meters to the weak weathered granite section．

Research conclusions: Using the ，micro bench method based on the precise blasting technique and cantilever － assembly type multi functional mould frame can effectively enhance the excavation efficiency of the tunnel with weak surrounding rock，offer the bigger working space for subsequent processes，shorten the distance between the working face and the inverted arch and the secondary lining，and be beneficial to ensuring the construction safety and schedule．

Research conclusions: With the development of ventilating device，the high wind pressure and large air volume ventilation machine with high tenacity and large － diameter flexible ventilating duct has been developed，so it is possible to use the forced ventilation technology for long tunnel． This method is simple，convenient and fast． By reasonable application，the construction cost can be cut，and the good construction environment and construction schedule can be ensured．

Research conclusions: From the study，the following conclusions can be obtained: ( 1) The complete tunnel structural health monitoring system ( TSHMS) should be composed of the data collection ＆ transmission system，data analysis ＆ processing system and structural safety evaluation ＆ alarm system． ( 2) Through the analysis of mechanical evolution characteristics of the tunnel structure，the basic idea is presented that the long － term monitoring of the stress characteristics of the secondary lining should be especially conducted． ( 3) According to the complexity and indeterminacy characteristics of tunnel engineering，the fuzzy comprehensive evaluation means is introduced on the base of the conventional safety evaluation system． ( 4) With application of the concepts mentioned above in the super － long tunnel engineering of the Cangling highway，a preliminary TSHMS is established and the evaluation results are basically consistent with the actual situation，so this system is reliable．

Research conclusions: ( 1) AHM is reinforced after measure of 0． 1 － 0． 9 is introduced and quantitative criterion is calculated to achieve attribute judgment matrix． ( 2 ) AHM takes on characteristic of simple operation， strong adaptability，less calculation and is very suitable for location selection of railway passenger station．

Research conclusions: From the research and review of the installation processes of the pipe，device and alarm system and the system linkage test of a heptafluoropropane automatic fire extinguishing system for one office building，it is concluded the steel cylinder room is the core of the system． When installing and arranging the devices in the steel cylinder room，the operation space and the passage for test and maintenance should be reserved． The main a． c power to the main fire host，linkage cabinet and multi － functional console should be fed from the special UPS dual power supply in the fire control room．

Research conclusions: ( 1) The pattern of the surface settlement caused by the construction of the air duct can bedivided into five stages: zero deformation stage， micro deformation stage， aggravating deformation stage， slowdeformation stage and basically stable stage． ( 2) The impact on the surface settlement caused by the excavation support is up to 76． 6% ～ 92． 5% of the total surface settlement． ( 3) The impact on the surface settlement by the external loadon theroad can not be neglected． It is proposed that the steel plate is paved on the road surface to buffer and diffuse theexternal load．

Research conclusions: The comprehensive assessment with the indicator system shows that the China railway not only achieves an obviously quantatitive effect in the energy saving and environment protection，but also achieves an initiative effect in adjusting and optimizing the energy consumption structure by changing the energy saving from quantity to quality．

Research conclusions: From the view of environmental protection，the paper presents principle requirements for the proposed developing goal and layout of the railways " Twelfth Five － Year" development plan． It provides reference for plan’s compilation，optimization and approval decision making． Also，it provides vital safeguards for railway’s scientific development，safe development，sustainable development in the level of planning． Simultaneously，the paper proposes some suggestions in direction for follow － up implementation．