부산시 천성항 내 훼손이 예상되는 거머리말 서식지의 복원을 위해서 기존 서식지의 현황조사 를 실시하고 인근 두문리 해안에 대체서식지를 조성하여 모니터링을 실시하였다. 2014년 1월 항내 자생하는 거머리말은 수심 1.2∼3.1 m의 범위에서 출현하였고, 수온은 7.4℃, 염분은 29.1 psu, pH는 8.05를 나타냈다. 거머리말의 서식밀도는 167.1±16.4 shoots m-2로 조사되었고, 총길 이 48.5±18.1 cm, 엽초길이 9.1±2.8 cm, 엽폭 4.8±1.1 cm로 조사되었다. 2014년 12월에 이식을 실시한 후 다음해 8월까지 모니터링을 실시하였다. 이식 초기 서식밀도는 감소하여 1월에 8.5 shoots patch-1 값을 나타낸 이후 점차 증가하여 4월에 19.0 shoots patch-1 까지 증가하였다. 총 길이는 73.3±2.9∼121.3±6.1 cm, 엽초길이는 9.6±0.6∼21.0±1.2 cm, 엽폭은 5.7±0.1∼6.8±0.2 mm 로 조사되었고 측정값은 7월까지 꾸준히 증가하다 8월 이후에 감소하는 경향을 나타내었다. 천성항 내 거머리말 서식지와 이식 초기 대체서식지에서 관찰되지 않았던 생식지(flowering shoot)가 2015년 3월부터 나타나기 시작하여 모니터링 기간 동안 계속 관찰되었으며, 2016년 조사 시 생식지의 씨앗에서 발아한 거머리말을 대체서식지에서 관찰할 수 있었다.

A number of roller-compacted concrete pavements (RCCP) have been constructed without saw-cut joints in order to save construction cost. Then it will allow natural cracks to randomly occur at the early age after concrete placement. Crack spacing of unjointed RCCP is crucial to ensure an adequate crack width and load transfer across the cracks since large crack spacing will result in excessive crack width and reduce load transfer efficiency that may be cause faulting, excessive deflection, and further cracking in RCCP slab. Due to pavement thickness, climatic condition, and material properties, unjointed RCCP may have different natural crack spacing. In this study, an analytical approach to predict natural crack spacing of an unjointed RCCP was developed. An analytical method based on elastic theory to calculate axial restraint stress using a bilinear slab-subbase interfacial constraint assumption was conducted. Curling stress induced by temperature gradient through the depth of the slab was also considered. The analytical model incorporates the environmental effect, strength gain and modulus of elasticity, coefficient of thermal expansion, drying shrinkage, base type materials, and slab geometries. The predicted crack spacing results obtained from the predictive model were validated through field measured data. The results showed a good agreement compared with crack spacing measured in the field. Furthermore, the result from a sensitive analysis using proposed predictive model showed that crack spacing increased when thickness of RCCP increased. The predicted crack spacing results may be used as input parameters to estimate crack widths in unjointed RCCP under given climatic condition, and material properties. If estimated crack width is excessive and cannot maintain an adequate load transfer across the cracks, saw-cut joints with an appropriate spacing should be provided in order to minimize crack width, and to prevent future cracking of RCCP leading to better performance.

PURPOSES:Pavement textures can be categorized into four according to wavelength: microtexture, macrotexture, megatexture (roads), and roughness. Pavement surface texture influences a number of aspects of tire-pavement interaction such as wet-weather friction, tire-pavement noise, splash, spray, tire-wear, and rolling resistance. In particular, macrotexture is the pavement surface characteristic that considerably impacts tire-pavement noise. In general, it can be demonstrated that tire-pavement noise increases with the increase of texture depth and wavelength. Recently, mean profile depth (MPD) and wavelength have been used to evaluate tire-pavement noise. This study aimed to identify the relationship between mean profile depth and average wavelength for asphalt pavement based on the information obtained on a number of asphalt pavement sections.METHODS :Profile data were collected from a number of expressway sections in Korea. In addition, mean profile depth and average wavelength were calculated by using this profile data. Statistical analysis was performed to determine the correlationship between mean profile depth and average wavelength.RESULTS:This study demonstrates a linear relationship between mean profile depth and average wavelength for asphalt concrete pavement.CONCLUSIONS:The strong relationship between mean profile depth and average wavelength of asphalt pavement was determined in this study.