屋面防水浅议

简述了屋面产生渗漏的主要原因及注意事项；科学先进的防水设计、优质的防水材料和精心的施工是屋面防水质量的保证。     

Passive solar systems for heating, daylighting and ventilation for rooms without an equator-facing facade

Spaces without northerly orientations have an impact on the ‘energy behaviour’ of a building. This paper outlines possible energy savings and better performance achieved by different zenithal solar passive strategies (skylights, roof monitors and clerestory roof windows) and element arrangements across the roof in zones of cold to temperate climates typical of the central and central-southern Argentina. Analyses were undertaken considering daylighting, thermal and ventilation performances of the different strategies. The results indicate that heating, ventilation and lighting loads in spaces without an equator-facing facade can be significantly reduced by implementing solar passive strategies. In the thermal aspect, the solar saving fraction reached for the different strategies were averaged 43.16% for clerestories, 41.4% for roof monitors and 38.86% for skylights for a glass area of 9% to the floor area. The results also indicate average illuminance levels above 500 lux for the different clerestory and monitor arrangements, uniformity ratios of 0.66–0.82 for the most distributed arrangements and daylighting factors between 11.78 and 20.30% for clear sky conditions, depending on the strategy. In addition, minimum air changes rates of 4 were reached for the most extreme conditions.     

焦作煤田大煤顶分层沿空留巷合理支护形式分析

文章通过对焦作煤田大煤顶分层沿空留巷大量观测资料的分析,闸明在大煤既定的围岩特征和留巷所采用的支护方式条件下,“支驾——围岩”这一对相互作用的力学力系,在采场支承压力作用下趋向平衡时所呈现的矿压规律。从而分析留巷所采用的梯形“工”字钢支架,巷内架设抬棚的支护方式的合理性。     

热塑性硬质聚氨酯泡沫在汽车顶内饰中的应用

概述了汽车顶内饰用热塑性聚氨酯硬质泡沫塑料进展状况，介绍了硬泡及顶内饰成型方法，对影响该硬泡性能的一些因素进行了讨论。指出该顶内饰已批量生产。     

Development of a six drillhead roof bolting machine

In underground mining, machine design is predominantly dictated by mine conditions and individual customer desires. In partnership with Foresight Energy, J. H. Fletcher Company was tasked to design and manufacture a new roof bolting machine with six independent drilling apparatus on board capable of drilling and bolting the roof and ribs with material handling. The objective was to produce a machine capable of drilling and installing six bolts simultaneously with a limited number of operators. The goal of the mine is to decrease the time to bolt a cut to improve the safety level of the current roof bolting method, improve efficiency and to improve the bottom line cost of entry development. The customer wanted four drills at the front of the machine dedicated to installing roof bolts and then another two drills behind them dedicated to rib bolts. This dictated the requirement of latched controls, which would allow the operator to start drilling one hole and then latch the controls to be able to move on to the next.The result of the design is a machine with a single platform and six independent masts with drillheads:four masts strictly for drilling and installing roof bolts on the front of the platform and two masts on the back of the platform for rib bolts. The controls at each operator's station include a latch control for drilling. The six-head roof bolter allows fewer operators to drill and install roof and rib bolts, which in turn lowers the miners' roof exposure per cut. This design reduces the operator's exposure from the inherent pinch points and rotary hazards once he has engaged the latch drilling. Therefore, the machine will help to decrease the time to bolt a cut, improving productivity while enhancing the ability to operate the machine safely.     

Gateside packwall design in solid backfill mining-A case study

Based upon characteristic movement features of the overlying strata in solid backfill mining and in-situ observations,an associated model representing a roadway support system has been developed.Based on the Winkler foundation and beam model,the current study presents a static analysis of the model,thus permitting acquisition of a theoretical formula pertaining to roof convergence.Through use of working face 6304-1(Jisan Colliery) as the research setting,the association between roof convergence magnitude and both packwall strength and width have been elucidated.Based upon observed conditions at the working face,realistic packwall parameters have been formulated,with numerical simulation results and field application results indicating that design parameters garnered from the developed formula successfully adapted to local geological movement and deformation.Accordingly,roadway deformation was shown to be within the permissible range,thus satisfying mine production requirements.The proposed method in the current study may give a design basis for pack design in the context of SBM under similar conditions.     

Vertical load capacities of roof truss cross members

Trusses used for roof support in coal mines are constructed of two grouted bolts installed at opposing forty-five degree angles into the roof and a cross member that ties the angled bolts together. The load on the cross member is vertical, which is transverse to the longitudinal axis, and therefore the cross member is loaded in the weakest direction. Laboratory tests were conducted to determine the vertical load capacity and deflection of three different types of cross members. Single-point load tests, with the load applied in the center of the specimen and double-point load tests, with a span of 2.4 m, were conducted. For the single-point load configuration, the yield of the 25 mm solid bar cross member was nominally 98 kN of vertical load, achieved at 42 cm of deflection. For cable cross members, yield was not achieved even after 45 cm of deflection. Peak vertical loads were about 89 kN for 17 mm cables and67 kN for the 15 mm cables. For the double-point load configurations, the 25 mm solid bar cross members yielded at 150 kN of vertical load and 25 cm of deflection. At 25 cm of deflection individual cable strands started breaking at 133 and 111 kN of vertical load for the 17 and 15 mm cable cross members respectively.     

Mechanical analysis of roof stability under nonlinear compaction of solid backfill body

Based on the compaction characteristic test and the nonlinear compaction deformation characteristics of backfill material, this paper applies the theory of nonlinear elastic foundation of thin plate to establish a mechanical model of backfill body and roof in solid dense backfill coal mining. This study critically analyses the deflection equation of the roof by the energy method, derives the conditions of roof breakage and combined with concrete engineering practice analyses, determines roof movement regularity and stability in solid dense backfill mining. Analysis of the engineering practice of the 13,120 backfill panel of Pingmei 12# mine shows the theoretical maximum of roof convergence in backfill mining to be415 mm which is in significant agreement with the measured value. During the advancing process of solid backfill mining at the panel, the maximum tensile stress on the roof is less than its tensile strength which does not satisfy the conditions for roof breakage. Drilling results on the roof and ground pressure monitoring show that the integrity of roof is strong, which is consistent with the theoretical calculations described in this study. The results presented in the study provide a basis for further investigation into strata movement theory in solid dense backfill mining.     

A videogrammetric as-built data collection method for digital fabrication of sheet metal roof panels

A roofing contractor typically needs to acquire as-built dimensions of a roof structure several times over the course of its build because a structure is never built to the exact drawing dimensions. In the construction phase and in order to digitally fabricate sheet metal roof panels, the contractor has to measure end-to-end dimensions of boundaries of every roof plane with a certain level of accuracy (i.e., errors less than ±2 cm). This is necessary to be able to cut sheet metal coil such that different pieces perfectly fit together. Obtaining these measurements using the exiting roof surveying methods could be costly in terms of equipment, labor, and/or worker exposure to safety hazards. This paper presents a video-based surveying framework as an alternative method which is simple to use, automated, less expensive, and safe. When using this framework, the contractor collects video streams with a calibrated stereo camera set. The captured data is processed to automatically generate a 3D wire-diagram of the target roof. Measurements from the wire-diagram are saved in a digital file (XML format) which could be loaded into an on-site sheet metal folding and cutting machine. Experimental analyses demonstrate applicability of the proposed framework.     

Combined freeze-sealing and New Tubular Roof construction methods for seaside urban tunnel in soft ground

Construction of seaside urban tunnels is significantly difficult due to the densely adjacent buildings and underground facilities in conjunction with unfavourable geological conditions. For this, this paper investigates the construction methods used for Gongbei Tunnel, which is a typical seaside tunnel connecting Hong Kong-Zhuhai-Macau Bridge in China. The construction methods and stability of the undercutting section will be focused. In the tunnel section of interest, dozens of thick steel tubes are jacked into the soft soil, and freeze-sealing method is applied to form a thick water-proofing wall. In this study, the combined freezing and New Tubular Roof (NTR) method are simulated by thermo-mechanical coupling analysis. The temperature field obtained in the freezing process indicates that the thickness of frozen wall grows approx. 2.0 m after 50 days of freezing. Besides, the stability of the surrounding ground and supporting structures in the bench-cutting stage are also investigated. Then the thawing process is simulated and associated suggestions for post-grouting to prevent excessive thawing settlement are proposed. The numerical results show that the tunnel is stable and the influence of tunnel excavation on adjacent buildings is within the permissible range. It also shows that the designed construction methods can be used to adequately meet safety and stability standards when adopting the proposed construction and supporting system.