Abaqus numerical simulation was carried out for the aluminum honeycomb-polyurethane composite waterproof bottom plate and wall plate used in the prefabricated integral bathroom in the enterprise incubation base project of Sanya Central Business District.Taking the construction and use situation into full consideration,the uniform load was used to simulate the static position of large equipment and the concentrated load was used to simulate the situation of single point hanging heavy objects.The stress distribution,displacement distribution,maximum stress and maximum displacement under the concentrated load of 20 t·m-2 and 800 kN are analyzed.
Taking ordinary mortar as the research object,after standard curing and absolute wet curing for 3 d,7 d and 28 d,the mortar was subjected to high temperature treatment at 300℃,500℃and 700℃,respectively.After cooling,the mechanical properties of mortar test blocks were tested to study the effects of curing method,age and treatment temperature on mechanical properties of mortar test blocks.The test results show that with the increase of treatment temperature,the fracture resistance and compressive strength of mortar test block decrease continuously,and the earlier the age,the greater the effect of temperature.In addition,the mechanical properties of the absolute wet curing blocks were smaller than those of the standard curing blocks.
The traditional design of subsea structures pays more attention to the analysis of structural elements under normal operation,while more advanced methods are needed to deal with sudden conditions.The finite element method based on the Coupled Eulerian-lagrangian(CEL)method can efficiently deal with the transient and large deformation problems.Therefore,this method is used to simulate the collision between the liquid storage tank falling into water and the underwater structure,and the results are analyzed and discussed.
Based on the restraint mechanism of FRP-constrained concrete cylinder,the type,structure,characteristics and influencing factors of stress and strain models of FRP restraint concrete were analyzed,and then the lateral restraint and lateral expansion coefficient of restraint concrete were discussed.
Combined with the preparation method of modified aerogel,the thermal insulation coating based on polymer modified SiO2 aerogel was prepared,and the performance of modified aerogel and the thermal insulation performance of the coating were tested.The results showed that the modification scheme was feasible.
Taking a city in Shanxi Province as an example,the effect of the increase of urban vehicles on the concentration of PM2.5 in the air was studied.The results show that industrial production,agricultural activities and transportation are the main pollution sources of PM2.5 in urban air,and motor vehicle exhaust from transportation contributes significantly to the increase of PM2.5 concentration.At the same time,it is found that there are differences in PM2.5 emission between gasoline vehicles and diesel vehicles,and different models have their own emission characteristics.Through comparative analysis,the close positive correlation between PM2.5 concentration and traffic flow was established.
In view of the lack of durability of ordinary reinforced concrete,a new structure composed of FRP bars and UHPC is proposed,and the premise is that they have good bonding properties,so that they can be stressed simultaneously under load.Based on this,4 groups of central drawing specimens were made with the type,surface treatment and diameter of the rebar as variables,and the bonding properties and influencing factors of GFRP bars and UHPC were verified through laboratory tests.The results show that GFRP bars and ordinary bars have similar bond slip curve characteristics.Under the same conditions,the bonding property of ordinary steel bars and UHPC bars is better than that of GFRP bars,and the slip amount of ordinary steel bars is smaller under the same bonding stress.The bonding properties of GFRP bars with ribbed surface and UHPC are better than those of ordinary concrete.The greater the diameter of the steel bar,the ultimate bond stress decreases slowly,and the ultimate load increases gradually.
In order to explore the surrounding rock mechanical properties and construction deformation of ultra-shallow buried tunnel under the gully terrain,based on the study of the Dabao tunnel project of Leishan-Rongjiang Expressway in Guizhou,the three-dimensional numerical simulation of the tunnel construction was carried out using Flac3D based on the finite difference method,and the maximum vault settlement of the tunnel was predicted to be 8.25 mm,and the maximum horizontal displacement was 4.60 mm.The results are basically consistent with the field measurement,showing that the support system works well.The surrounding rock around the tunnel is mainly subjected to tensile yield,which is mainly concentrated in the vault,spandrel and invert.There are longitudinal differences in the settlement rate of each point on the surface of the gully.
Combined with the earthwork backfill engineering example of the independent foundation of large public buildings,this paper analyzes the main reasons for the uneven settlement between the independent foundation and the floor,studies the pre-control measures of the uneven settlement,and reduces the cracking and other diseases caused by the uneven settlement after construction of the floor.In the backfilling of the independent foundation fertilizer tank and the ground soil,three measures,including controlling the physical property index of the backfill material and the filling construction quality,adopting the co-settlement control technology of the independent foundation and the floor,and improving the overall stiffness of the concrete floor,have a good effect on the pre-control of the uneven settlement of the independent foundation and the floor.
The distribution of soil resistance around the pile shaft is one of the key parameters in the design of pile foundation engineering.Therefore,accurately obtaining the pile-side soil resistance parameters is a crucial factor in optimizing the selection and layout design of pile foundations.This paper discussed the principle of the high strain dynamic measurement technique.By conducting high strain dynamic tests on static load test piles in prestressed concrete pipe pile projects,the collected force and velocity signals are analyzed using the curve fitting method.The distribution data of soil resistance in each soil layer around the pipe piles are calculated,providing more scientifically and reasonably soil resistance parameters for optimizing the selection and layout design of engineering piles.
A powder aerogel with an average pore size of 30 nm and a specific surface area of 624.32 m2·g-1 was prepared by atmospheric drying.The results showed that the aerogel dispersion was better when the emulsifier concentration was 0.003 mol·L-1.With the increase of emulsifier concentration,the porosity gradually increased and then decreased,and the highest porosity reached 95.54%.When the content of surface modifier is 60%of gel volume,the optimal density is 0.102 g·cm-3.
The history and culture of each era have left a deep imprint on the architecture,and architectural decoration is the most classic part of traditional architecture,which has developed into a unique regional decoration after thousands of years of time changes.Through the analysis of the background,decorative elements,color,style and sculpture of the traditional residential buildings in Jingsha area,this paper discusses the characteristics of the traditional residential buildings in this area,such as the function,beautification and implication.
Based on the principle of economic reliability,the SNCR denitration scheme was adopted in the cement clinker firing system,and through the use of low NOx burner at the kiln head,the establishment of ammonia-free denitration zone of the calciner,and the optimization of the position and proportion of ammonia injection,the ultra-low emission of nitrogen oxide in the flue gas of the firing system was realized.
In order to analyze the property of corroded steel bars and their impact on concrete bond force,inspection on the corroded steel bars of a construction project on-site was carried out firstly.And then,the weight deviation and mechanical properties of the corroded steel bars were tested.Finally,bond force between corroded steel bars and concrete was tested through pull-out tests.The inspection and experimental results show that the corrosion of the steel bars has no significant impact on their weight deviation,mechanical properties,and the concrete bond force.The weight deviation and mechanical properties of the corroded steel bars meet the requirements of the specifications.The bond force between corroded steel bars and concrete is in accordance with the safety requirements.However,rust of the corroded steel bars should be cleaned before pouring concrete.
Combined with the external thermal insulation system of the building exterior wall and its technical characteristics,the warehouse type protection template with extruded polystyrene board(XPS)as insulation core layer was designed in this paper.The prepared sample test shows that the thermal conductivity of the template is 0.029 5 W·m-1·K-1,and the thermal insulation performance is good.According to GB/T 29416-2012,the third party testing institution conducted fire performance test on the composite insulation system of warehouse type protection template,and the inspection result was qualified.
Based on a certain number of acoustic sensor microphone arrays,the acoustic field environmental signals were sampled and calculated to determine the location of its sound source.In the overall design,the microphone array is used to collect the sound signals from the stationary or moving objects in the sound field environment,which are transmitted to the STM32 MCU main control core.The K210 development module uses the time delay estimation algorithm to calculate the linear distance between the microphone array and the object sound source,and then converts the angle between the two.PWM uses the pulse width wave to control the steering gear to drive the infrared laser instrument to turn to the position of the sound source,and at the same time,the accurate angle and orientation of the sound source target are displayed on the OLED screen in real time.The results show that the system can locate the single sound source with high accuracy,and can be used for information collection and location of unmanned photography and traffic intersection guidance.
Based on the terrain and landform of Southeast Guizhou,the basic form of"Semi-columnar Style"such as plane,elevation and section is analyzed,and its construction function needs and architectural characteristics are analyzed in combination with the cultural background.Through the comparative analysis of the"Semi-columnar Style"and the whole stilt structure,it is known that the force of the whole stilt timber structure is more reasonable than that of the"Semi-columnar Style".
在城市更新过程中,经常会出现历史文化遗产被破坏或流失等问题.因而在城市更新过程中注重文化传承变得尤为重要.为此以大连城市更新为研究对象,分析了其发展历程和现状.通过对文化传承的探讨,提出了在城市更新过程中注重历史文化传承的策略,并结合大连市的城市更新情况,从政策、设计和管理等方面提出了具体的实施方案.
为了探究我国建筑行业BIM应用满意度的影响机制,通过查阅文献,筛选并分析 BIM 应用满意度的影响因素,形成结构方程模型(SEM)的变量表.根据变量表设计并发放调查问卷,并使用SPSS 26 软件和Amos 23 软件对调查数据进行描述性统计、信度、效度、正态性、相关性和结构方程模型等分析.结果表明:技术因素、组织因素、环境因素和使用者意愿对我国建筑行业的BIM应用满意度有正向显著性影响.
采用Na2CO3 溶液对粒径<4.75 mm的生活焚烧炉渣进行预处理,有效去除其中残余金属Al以及部分硫化物、氯盐,增加玻璃相含量.以其部分取代河砂制备混合砂,会导致砂浆拌合物减水剂用量有所增大,但能够有效改善细骨料级配,显著提高砂浆保水能力,降低其表观密度.不同炉渣取代率的混合砂中,M5 砂浆最佳取代率为20%,M10 砂浆为40%,M15 砂浆抗压强度随着炉渣掺量的增加呈现下降的趋势.
